#!/usr/bin/env python3
"""
Burn Rate & Runway Calculator
==============================
Models startup runway across base/bull/bear scenarios, incorporating
a hiring plan and revenue trajectory. Outputs months of runway,
cash-out dates, and decision trigger points.

Usage:
    python burn_rate_calculator.py
    python burn_rate_calculator.py --csv  # export to CSV

Stdlib only. No dependencies.
"""

import argparse
import csv
import io
import sys
from dataclasses import dataclass, field
from datetime import date, timedelta
from typing import Optional


# ---------------------------------------------------------------------------
# Data structures
# ---------------------------------------------------------------------------

@dataclass
class HiringEntry:
    """A planned hire."""
    month: int          # months from model start (1-indexed)
    role: str
    department: str     # "sales", "engineering", "cs", "ga"
    annual_salary: float
    benefits_pct: float = 0.22  # benefits as % of salary
    recruiting_cost: float = 0.0  # one-time recruiting fee


@dataclass
class RevenueEntry:
    """Monthly revenue data point (historical or projected)."""
    month: int
    mrr: float          # monthly recurring revenue
    one_time: float = 0.0


@dataclass
class ModelConfig:
    """Master configuration for a runway scenario."""
    name: str
    starting_cash: float
    starting_mrr: float
    starting_headcount: int
    avg_loaded_salary: float        # average fully-loaded salary per current employee
    base_non_headcount_opex: float  # monthly non-headcount costs (infra, tools, etc.)
    gross_margin_pct: float         # 0.0–1.0
    mrr_growth_rate: float          # monthly MoM growth rate, 0.0–1.0
    hiring_plan: list[HiringEntry] = field(default_factory=list)
    model_months: int = 24
    start_date: Optional[date] = None


@dataclass
class MonthResult:
    """Single month output."""
    month: int
    label: str              # e.g. "Month 1 (Apr 2025)"
    mrr: float
    gross_profit: float
    headcount: int
    headcount_cost: float   # total loaded headcount cost this month
    other_opex: float
    gross_burn: float
    net_burn: float
    cash_start: float
    cash_end: float
    runway_months: float    # projected runway from this month
    cumulative_new_arr: float   # for burn multiple


# ---------------------------------------------------------------------------
# Core calculator
# ---------------------------------------------------------------------------

class RunwayCalculator:

    def __init__(self, config: ModelConfig):
        self.cfg = config

    def run(self) -> list[MonthResult]:
        cfg = self.cfg
        results = []

        # Build headcount schedule: month -> list of new hires starting that month
        hire_by_month: dict[int, list[HiringEntry]] = {}
        for h in cfg.hiring_plan:
            hire_by_month.setdefault(h.month, []).append(h)

        # Track existing employees
        active_employees: list[dict] = []
        for _ in range(cfg.starting_headcount):
            active_employees.append({
                "monthly_loaded": cfg.avg_loaded_salary / 12 * 1.0,
                "start_month": 0,
            })

        cash = cfg.starting_cash
        mrr = cfg.starting_mrr
        cumulative_new_arr = 0.0
        starting_mrr = cfg.starting_mrr

        for m in range(1, cfg.model_months + 1):
            # Process new hires this month
            one_time_recruiting = 0.0
            if m in hire_by_month:
                for hire in hire_by_month[m]:
                    monthly_loaded = (
                        hire.annual_salary * (1 + hire.benefits_pct) / 12
                    )
                    active_employees.append({
                        "monthly_loaded": monthly_loaded,
                        "start_month": m,
                    })
                    one_time_recruiting += hire.recruiting_cost

            # Revenue this month
            mrr = mrr * (1 + cfg.mrr_growth_rate)
            gross_profit = mrr * cfg.gross_margin_pct

            # Headcount cost
            headcount_cost = sum(e["monthly_loaded"] for e in active_employees)
            headcount_cost += one_time_recruiting

            # Other opex (infra, SaaS tools, office, etc.)
            other_opex = cfg.base_non_headcount_opex

            # Burn
            gross_burn = headcount_cost + other_opex
            net_burn = gross_burn - gross_profit

            # Cash
            cash_start = cash
            cash = cash - net_burn
            cash_end = cash

            # Projected runway from this month (using current net burn rate)
            runway = cash_end / net_burn if net_burn > 0 else float("inf")

            # Cumulative new ARR (for burn multiple calc)
            new_mrr_added = mrr - starting_mrr if m == 1 else mrr - results[-1].mrr
            cumulative_new_arr += new_mrr_added * 12

            # Label
            if cfg.start_date:
                month_date = date(
                    cfg.start_date.year,
                    cfg.start_date.month,
                    1,
                ) + timedelta(days=32 * (m - 1))
                month_date = month_date.replace(day=1)
                label = f"Month {m:02d} ({month_date.strftime('%b %Y')})"
            else:
                label = f"Month {m:02d}"

            results.append(MonthResult(
                month=m,
                label=label,
                mrr=mrr,
                gross_profit=gross_profit,
                headcount=len(active_employees),
                headcount_cost=headcount_cost,
                other_opex=other_opex,
                gross_burn=gross_burn,
                net_burn=net_burn,
                cash_start=cash_start,
                cash_end=cash_end,
                runway_months=runway,
                cumulative_new_arr=cumulative_new_arr,
            ))

            # Stop if cash runs out
            if cash_end <= 0:
                break

        return results

    def cash_out_date(self, results: list[MonthResult]) -> Optional[str]:
        """Return the label of the month cash runs out, or None if model survives."""
        for r in results:
            if r.cash_end <= 0:
                return r.label
        return None

    def burn_multiple(self, results: list[MonthResult]) -> float:
        """Burn multiple = total net burn / total net new ARR over model period."""
        total_net_burn = sum(r.net_burn for r in results if r.net_burn > 0)
        first_mrr = results[0].mrr / (1 + self.cfg.mrr_growth_rate)  # starting mrr
        total_new_arr = (results[-1].mrr - first_mrr) * 12
        if total_new_arr <= 0:
            return float("inf")
        return total_net_burn / total_new_arr


# ---------------------------------------------------------------------------
# Reporting
# ---------------------------------------------------------------------------

def fmt_k(value: float) -> str:
    """Format as $Xk or $X.XM."""
    if abs(value) >= 1_000_000:
        return f"${value/1_000_000:.2f}M"
    if abs(value) >= 1_000:
        return f"${value/1_000:.0f}K"
    return f"${value:.0f}"


def print_summary(name: str, results: list[MonthResult], calc: RunwayCalculator) -> None:
    cash_out = calc.cash_out_date(results)
    bm = calc.burn_multiple(results)
    last = results[-1]
    first = results[0]

    print(f"\n{'='*60}")
    print(f"  SCENARIO: {name}")
    print(f"{'='*60}")
    print(f"  Months modeled:    {len(results)}")
    print(f"  Cash out:          {cash_out or 'Does not run out in model period'}")
    print(f"  Ending cash:       {fmt_k(last.cash_end)}")
    print(f"  Final runway:      {last.runway_months:.1f} months")
    print(f"  Starting MRR:      {fmt_k(first.mrr)}")
    print(f"  Ending MRR:        {fmt_k(last.mrr)}")
    print(f"  Ending headcount:  {last.headcount}")
    print(f"  Burn multiple:     {bm:.2f}x")
    print(f"  Avg net burn:      {fmt_k(sum(r.net_burn for r in results)/len(results))}/mo")

    # Decision triggers
    print(f"\n  Decision Triggers:")
    triggers = {9: "⚠️  START FUNDRAISE", 6: "🔴 COST REDUCTION PLAN", 4: "🚨 EXECUTE CUTS / BRIDGE"}
    shown = set()
    for r in results:
        for threshold, label in triggers.items():
            if r.runway_months <= threshold and threshold not in shown:
                print(f"    {r.label}: {label} (runway = {r.runway_months:.1f} mo)")
                shown.add(threshold)


def print_monthly_table(results: list[MonthResult], max_rows: int = 24) -> None:
    header = f"{'Month':<22} {'MRR':>10} {'Hdct':>6} {'Net Burn':>12} {'Cash':>12} {'Runway':>8}"
    print(f"\n{header}")
    print("-" * len(header))
    for r in results[:max_rows]:
        runway_str = f"{r.runway_months:.1f}mo" if r.runway_months != float("inf") else "∞"
        print(
            f"{r.label:<22} "
            f"{fmt_k(r.mrr):>10} "
            f"{r.headcount:>6} "
            f"{fmt_k(r.net_burn):>12} "
            f"{fmt_k(r.cash_end):>12} "
            f"{runway_str:>8}"
        )


def export_csv(scenarios: list[tuple[str, list[MonthResult]]]) -> str:
    buf = io.StringIO()
    writer = csv.writer(buf)
    writer.writerow([
        "Scenario", "Month", "Label", "MRR", "Gross Profit", "Headcount",
        "Headcount Cost", "Other Opex", "Gross Burn", "Net Burn",
        "Cash Start", "Cash End", "Runway Months"
    ])
    for name, results in scenarios:
        for r in results:
            writer.writerow([
                name, r.month, r.label,
                round(r.mrr, 2), round(r.gross_profit, 2), r.headcount,
                round(r.headcount_cost, 2), round(r.other_opex, 2),
                round(r.gross_burn, 2), round(r.net_burn, 2),
                round(r.cash_start, 2), round(r.cash_end, 2),
                round(r.runway_months, 2),
            ])
    return buf.getvalue()


# ---------------------------------------------------------------------------
# Sample data
# ---------------------------------------------------------------------------

def make_sample_configs() -> list[ModelConfig]:
    """
    Sample company: Series A SaaS startup
      - $3M cash on hand (post Series A)
      - $125K MRR (~$1.5M ARR)
      - 18 employees, $150K avg salary
      - $80K/mo non-headcount opex (infra, tools, office)
      - 72% gross margin
    """
    common_kwargs = dict(
        starting_cash=3_000_000,
        starting_mrr=125_000,
        starting_headcount=18,
        avg_loaded_salary=150_000,
        base_non_headcount_opex=80_000,
        gross_margin_pct=0.72,
        model_months=24,
        start_date=date(2025, 1, 1),
    )

    # Base: 10% MoM growth, moderate hiring
    base_hiring = [
        HiringEntry(month=2,  role="AE #1",         department="sales",       annual_salary=120_000, recruiting_cost=18_000),
        HiringEntry(month=3,  role="Senior SWE #1",  department="engineering", annual_salary=160_000, recruiting_cost=24_000),
        HiringEntry(month=5,  role="SDR #1",         department="sales",       annual_salary=80_000,  recruiting_cost=12_000),
        HiringEntry(month=6,  role="CSM #1",         department="cs",          annual_salary=90_000,  recruiting_cost=13_500),
        HiringEntry(month=8,  role="AE #2",          department="sales",       annual_salary=120_000, recruiting_cost=18_000),
        HiringEntry(month=9,  role="Senior SWE #2",  department="engineering", annual_salary=165_000, recruiting_cost=24_750),
        HiringEntry(month=12, role="Controller",     department="ga",          annual_salary=130_000, recruiting_cost=19_500),
        HiringEntry(month=14, role="AE #3",          department="sales",       annual_salary=125_000, recruiting_cost=18_750),
        HiringEntry(month=15, role="ML Engineer",    department="engineering", annual_salary=175_000, recruiting_cost=26_250),
        HiringEntry(month=18, role="AE #4",          department="sales",       annual_salary=125_000, recruiting_cost=18_750),
    ]

    # Bull: 15% MoM growth, full hiring plan
    bull_hiring = base_hiring + [
        HiringEntry(month=4,  role="Marketing Manager", department="sales",       annual_salary=110_000, recruiting_cost=16_500),
        HiringEntry(month=7,  role="Senior SWE #3",     department="engineering", annual_salary=165_000, recruiting_cost=24_750),
        HiringEntry(month=10, role="AE #5",              department="sales",       annual_salary=125_000, recruiting_cost=18_750),
        HiringEntry(month=13, role="DevOps Engineer",    department="engineering", annual_salary=150_000, recruiting_cost=22_500),
        HiringEntry(month=16, role="AE #6",              department="sales",       annual_salary=125_000, recruiting_cost=18_750),
    ]

    # Bear: 5% MoM growth, hiring freeze after month 3
    bear_hiring = [
        HiringEntry(month=2, role="AE #1",        department="sales",       annual_salary=120_000, recruiting_cost=18_000),
        HiringEntry(month=3, role="Senior SWE #1", department="engineering", annual_salary=160_000, recruiting_cost=24_000),
    ]

    return [
        ModelConfig(name="BULL  (15% MoM, full hiring)",       mrr_growth_rate=0.15, hiring_plan=bull_hiring,  **common_kwargs),
        ModelConfig(name="BASE  (10% MoM, planned hiring)",     mrr_growth_rate=0.10, hiring_plan=base_hiring,  **common_kwargs),
        ModelConfig(name="BEAR  ( 5% MoM, hiring freeze M3+)", mrr_growth_rate=0.05, hiring_plan=bear_hiring,  **common_kwargs),
        ModelConfig(name="DISTRESS (0% growth, freeze now)",    mrr_growth_rate=0.00, hiring_plan=[],           **common_kwargs),
    ]


# ---------------------------------------------------------------------------
# Entry point
# ---------------------------------------------------------------------------

def main() -> None:
    parser = argparse.ArgumentParser(description="Startup Burn Rate & Runway Calculator")
    parser.add_argument("--csv", action="store_true", help="Export full monthly data as CSV to stdout")
    parser.add_argument("--scenario", choices=["bull", "base", "bear", "distress", "all"], default="all")
    args = parser.parse_args()

    configs = make_sample_configs()
    if args.scenario != "all":
        configs = [c for c in configs if args.scenario.upper() in c.name.upper()]

    all_results: list[tuple[str, list[MonthResult]]] = []

    print("\n" + "="*60)
    print("  BURN RATE & RUNWAY CALCULATOR")
    print("  Sample Company: Series A SaaS Startup")
    print("  Starting cash: $3M | Starting MRR: $125K | 18 employees")
    print("="*60)

    for cfg in configs:
        calc = RunwayCalculator(cfg)
        results = calc.run()
        all_results.append((cfg.name, results))
        print_summary(cfg.name, results, calc)
        print_monthly_table(results)

    # Comparison summary
    print("\n" + "="*60)
    print("  SCENARIO COMPARISON")
    print("="*60)
    print(f"  {'Scenario':<40} {'Runway':>8} {'Cash Out':<30} {'Burn Mult':>10}")
    print("  " + "-"*88)
    for cfg, (name, results) in zip(configs, all_results):
        calc = RunwayCalculator(cfg)
        cash_out = calc.cash_out_date(results) or "Survives model period"
        bm = calc.burn_multiple(results)
        final_runway = results[-1].runway_months
        runway_str = f"{final_runway:.1f}mo" if final_runway != float("inf") else "∞"
        bm_str = f"{bm:.2f}x" if bm != float("inf") else "∞"
        print(f"  {name:<40} {runway_str:>8} {cash_out:<30} {bm_str:>10}")

    print("\n  Decision Trigger Reference:")
    print("    9 months runway → Start fundraise process")
    print("    6 months runway → Begin cost reduction planning")
    print("    4 months runway → Execute cuts; explore bridge financing")
    print("    3 months runway → Emergency plan only")

    if args.csv:
        print("\n\n--- CSV EXPORT ---\n")
        sys.stdout.write(export_csv(all_results))


if __name__ == "__main__":
    main()

#!/usr/bin/env python3
"""
Fundraising Model
==================
Cap table management, dilution modeling, and multi-round scenario planning.
Know exactly what you're giving up before you walk into any negotiation.

Covers:
  - Cap table state at each round
  - Dilution per shareholder per round
  - Option pool shuffle impact
  - Multi-round projections (Seed → A → B → C)
  - Return scenarios at different exit valuations

Usage:
    python fundraising_model.py
    python fundraising_model.py --exit 150  # model at $150M exit
    python fundraising_model.py --csv

Stdlib only. No dependencies.
"""

import argparse
import csv
import io
import sys
from dataclasses import dataclass, field
from typing import Optional


# ---------------------------------------------------------------------------
# Data structures
# ---------------------------------------------------------------------------

@dataclass
class Shareholder:
    """A shareholder in the cap table."""
    name: str
    share_class: str        # "common", "preferred", "option"
    shares: float
    invested: float = 0.0   # total cash invested
    is_option_pool: bool = False


@dataclass
class RoundConfig:
    """Configuration for a financing round."""
    name: str                       # e.g. "Series A"
    pre_money_valuation: float
    investment_amount: float
    new_option_pool_pct: float = 0.0    # % of POST-money to allocate to new options
    option_pool_pre_round: bool = True  # True = pool created before round (dilutes founders)
    lead_investor_name: str = "New Investor"
    share_price_override: Optional[float] = None  # if None, computed from valuation


@dataclass
class CapTableEntry:
    """A row in the cap table at a point in time."""
    name: str
    share_class: str
    shares: float
    pct_ownership: float
    invested: float
    is_option_pool: bool = False


@dataclass
class RoundResult:
    """Snapshot of cap table after a round closes."""
    round_name: str
    pre_money_valuation: float
    investment_amount: float
    post_money_valuation: float
    price_per_share: float
    new_shares_issued: float
    option_pool_shares_created: float
    total_shares: float
    cap_table: list[CapTableEntry]


@dataclass
class ExitAnalysis:
    """Proceeds to each shareholder at an exit."""
    exit_valuation: float
    shareholder: str
    shares: float
    ownership_pct: float
    proceeds_common: float          # if all preferred converts to common
    invested: float
    moic: float                     # multiple on invested capital (for investors)


# ---------------------------------------------------------------------------
# Core cap table engine
# ---------------------------------------------------------------------------

class CapTable:
    """Manages a cap table through multiple rounds."""

    def __init__(self):
        self.shareholders: list[Shareholder] = []
        self._total_shares: float = 0.0

    def add_shareholder(self, sh: Shareholder) -> None:
        self.shareholders.append(sh)
        self._total_shares += sh.shares

    def total_shares(self) -> float:
        return sum(s.shares for s in self.shareholders)

    def snapshot(self, label: str = "") -> list[CapTableEntry]:
        total = self.total_shares()
        return [
            CapTableEntry(
                name=s.name,
                share_class=s.share_class,
                shares=s.shares,
                pct_ownership=s.shares / total if total > 0 else 0,
                invested=s.invested,
                is_option_pool=s.is_option_pool,
            )
            for s in self.shareholders
        ]

    def execute_round(self, config: RoundConfig) -> RoundResult:
        """
        Execute a financing round:
        1. (Optional) Create option pool pre-round (dilutes existing shareholders)
        2. Issue new shares to investor at round price
        Returns a RoundResult with full cap table snapshot.
        """
        current_total = self.total_shares()

        # Step 1: Option pool shuffle (if pre-round)
        option_pool_shares_created = 0.0
        if config.new_option_pool_pct > 0 and config.option_pool_pre_round:
            # Target: post-round option pool = new_option_pool_pct of total post-money shares
            # Solve: pool_shares / (current_total + pool_shares + new_investor_shares) = target_pct
            # This requires iteration because new_investor_shares also depends on pool_shares
            # Simplification: create pool based on post-round total (slightly approximated)
            target_post_round_pct = config.new_option_pool_pct
            post_money = config.pre_money_valuation + config.investment_amount

            # Estimate shares per dollar (price per share)
            price_per_share = config.pre_money_valuation / current_total
            new_investor_shares_estimate = config.investment_amount / price_per_share

            # Pool shares needed so that pool / total_post = target_pct
            total_post_estimate = current_total + new_investor_shares_estimate
            pool_shares_needed = (target_post_round_pct * total_post_estimate) / (1 - target_post_round_pct)

            # Check if existing pool is sufficient
            existing_pool = next(
                (s.shares for s in self.shareholders if s.is_option_pool), 0
            )
            additional_pool_needed = max(0, pool_shares_needed - existing_pool)

            if additional_pool_needed > 0:
                option_pool_shares_created = additional_pool_needed
                # Add to existing pool or create new
                pool_sh = next((s for s in self.shareholders if s.is_option_pool), None)
                if pool_sh:
                    pool_sh.shares += additional_pool_needed
                else:
                    self.shareholders.append(Shareholder(
                        name="Option Pool",
                        share_class="option",
                        shares=additional_pool_needed,
                        is_option_pool=True,
                    ))

        # Step 2: Price per share (after pool creation)
        current_total_post_pool = self.total_shares()
        if config.share_price_override:
            price_per_share = config.share_price_override
        else:
            price_per_share = config.pre_money_valuation / current_total_post_pool

        # Step 3: New shares for investor
        new_shares = config.investment_amount / price_per_share

        # Step 4: Add investor to cap table
        self.shareholders.append(Shareholder(
            name=config.lead_investor_name,
            share_class="preferred",
            shares=new_shares,
            invested=config.investment_amount,
        ))

        post_money = config.pre_money_valuation + config.investment_amount
        total_post = self.total_shares()

        return RoundResult(
            round_name=config.name,
            pre_money_valuation=config.pre_money_valuation,
            investment_amount=config.investment_amount,
            post_money_valuation=post_money,
            price_per_share=price_per_share,
            new_shares_issued=new_shares,
            option_pool_shares_created=option_pool_shares_created,
            total_shares=total_post,
            cap_table=self.snapshot(),
        )

    def analyze_exit(self, exit_valuation: float) -> list[ExitAnalysis]:
        """
        Simple exit analysis: all preferred converts to common, proceeds split pro-rata.
        (Does not model liquidation preferences — see fundraising_playbook.md for that.)
        """
        total = self.total_shares()
        price_per_share = exit_valuation / total
        results = []
        for s in self.shareholders:
            if s.is_option_pool:
                continue  # unissued options don't receive proceeds
            proceeds = s.shares * price_per_share
            moic = proceeds / s.invested if s.invested > 0 else 0.0
            results.append(ExitAnalysis(
                exit_valuation=exit_valuation,
                shareholder=s.name,
                shares=s.shares,
                ownership_pct=s.shares / total,
                proceeds_common=proceeds,
                invested=s.invested,
                moic=moic,
            ))
        return sorted(results, key=lambda x: x.proceeds_common, reverse=True)


# ---------------------------------------------------------------------------
# Reporting
# ---------------------------------------------------------------------------

def fmt(value: float, prefix: str = "$") -> str:
    if value == float("inf"):
        return "∞"
    if abs(value) >= 1_000_000:
        return f"{prefix}{value/1_000_000:.2f}M"
    if abs(value) >= 1_000:
        return f"{prefix}{value/1_000:.0f}K"
    return f"{prefix}{value:.2f}"


def print_round_result(result: RoundResult, prev_cap_table: Optional[list[CapTableEntry]] = None) -> None:
    print(f"\n{'='*70}")
    print(f"  {result.round_name.upper()}")
    print(f"{'='*70}")
    print(f"  Pre-money valuation:   {fmt(result.pre_money_valuation)}")
    print(f"  Investment:            {fmt(result.investment_amount)}")
    print(f"  Post-money valuation:  {fmt(result.post_money_valuation)}")
    print(f"  Price per share:       {fmt(result.price_per_share, '$')}")
    print(f"  New shares issued:     {result.new_shares_issued:,.0f}")
    if result.option_pool_shares_created > 0:
        print(f"  Option pool created:   {result.option_pool_shares_created:,.0f} shares")
        print(f"  ⚠️  Pool created pre-round: dilutes existing shareholders, not new investor")
    print(f"  Total shares post:     {result.total_shares:,.0f}")

    print(f"\n  {'Shareholder':<22} {'Shares':>12} {'Ownership':>10}  {'Invested':>10}  {'Δ Ownership':>12}")
    print("  " + "-"*68)

    prev_map = {e.name: e.pct_ownership for e in prev_cap_table} if prev_cap_table else {}

    for entry in result.cap_table:
        delta = ""
        if entry.name in prev_map:
            change = (entry.pct_ownership - prev_map[entry.name]) * 100
            delta = f"{change:+.1f}pp"
        elif not entry.is_option_pool:
            delta = "new"

        invested_str = fmt(entry.invested) if entry.invested > 0 else "-"
        print(
            f"  {entry.name:<22} {entry.shares:>12,.0f} "
            f"{entry.pct_ownership*100:>9.2f}%  {invested_str:>10}  {delta:>12}"
        )


def print_exit_analysis(results: list[ExitAnalysis], exit_valuation: float) -> None:
    print(f"\n{'='*70}")
    print(f"  EXIT ANALYSIS @ {fmt(exit_valuation)} (all preferred converts to common)")
    print(f"{'='*70}")
    print(f"\n  {'Shareholder':<22} {'Ownership':>10} {'Proceeds':>12} {'Invested':>10} {'MOIC':>8}")
    print("  " + "-"*65)
    for r in results:
        moic_str = f"{r.moic:.1f}x" if r.moic > 0 else "n/a"
        invested_str = fmt(r.invested) if r.invested > 0 else "-"
        print(
            f"  {r.shareholder:<22} {r.ownership_pct*100:>9.2f}% "
            f"{fmt(r.proceeds_common):>12} {invested_str:>10} {moic_str:>8}"
        )
    print(f"\n  Note: Does not model liquidation preferences.")
    print(f"  Participating preferred reduces founder proceeds in most real exits.")
    print(f"  See references/fundraising_playbook.md for full liquidation waterfall.")


def print_dilution_summary(rounds: list[RoundResult]) -> None:
    print(f"\n{'='*70}")
    print(f"  DILUTION SUMMARY — FOUNDER PERSPECTIVE")
    print(f"{'='*70}")

    # Find all founders (common shareholders who aren't investors or option pool)
    founder_names = []
    for entry in rounds[0].cap_table:
        if entry.share_class == "common" and not entry.is_option_pool:
            founder_names.append(entry.name)

    if not founder_names:
        print("  No common shareholders found in initial cap table.")
        return

    header = f"  {'Round':<16}" + "".join(f"  {n:<16}" for n in founder_names) + f"  {'Total Inv':>12}"
    print(header)
    print("  " + "-" * (16 + 18 * len(founder_names) + 14))

    for result in rounds:
        cap_map = {e.name: e for e in result.cap_table}
        total_invested = sum(e.invested for e in result.cap_table if not e.is_option_pool)
        row = f"  {result.round_name:<16}"
        for name in founder_names:
            pct = cap_map[name].pct_ownership * 100 if name in cap_map else 0
            row += f"  {pct:>6.2f}%         "
        row += f"  {fmt(total_invested):>12}"
        print(row)


def export_csv_rounds(rounds: list[RoundResult]) -> str:
    buf = io.StringIO()
    writer = csv.writer(buf)
    writer.writerow(["Round", "Shareholder", "Share Class", "Shares", "Ownership Pct",
                     "Invested", "Pre Money", "Post Money", "Price Per Share"])
    for r in rounds:
        for entry in r.cap_table:
            writer.writerow([
                r.round_name, entry.name, entry.share_class,
                round(entry.shares, 0), round(entry.pct_ownership * 100, 4),
                round(entry.invested, 2), round(r.pre_money_valuation, 0),
                round(r.post_money_valuation, 0), round(r.price_per_share, 4),
            ])
    return buf.getvalue()


# ---------------------------------------------------------------------------
# Sample data: typical two-founder Series A/B/C startup
# ---------------------------------------------------------------------------

def build_sample_model() -> tuple[CapTable, list[RoundResult]]:
    """
    Sample company:
      - 2 founders, started with 10M shares each
      - 1M shares for early advisor
      - Raises Pre-seed → Seed → Series A → Series B → Series C
    """
    cap = CapTable()
    SHARES_PER_FOUNDER = 4_000_000
    SHARES_ADVISOR = 200_000

    # Founding state
    cap.add_shareholder(Shareholder("Founder A (CEO)", "common", SHARES_PER_FOUNDER))
    cap.add_shareholder(Shareholder("Founder B (CTO)", "common", SHARES_PER_FOUNDER))
    cap.add_shareholder(Shareholder("Advisor",         "common", SHARES_ADVISOR))

    rounds: list[RoundResult] = []
    prev_cap = cap.snapshot()

    # Round 1: Pre-seed — $500K at $4.5M pre, 10% option pool created
    r1 = cap.execute_round(RoundConfig(
        name="Pre-seed",
        pre_money_valuation=4_500_000,
        investment_amount=500_000,
        new_option_pool_pct=0.10,
        option_pool_pre_round=True,
        lead_investor_name="Angel Syndicate",
    ))
    rounds.append(r1)
    prev_r1 = r1.cap_table[:]

    # Round 2: Seed — $2M at $9M pre, expand option pool to 12%
    r2 = cap.execute_round(RoundConfig(
        name="Seed",
        pre_money_valuation=9_000_000,
        investment_amount=2_000_000,
        new_option_pool_pct=0.12,
        option_pool_pre_round=True,
        lead_investor_name="Seed Fund",
    ))
    rounds.append(r2)

    # Round 3: Series A — $12M at $38M pre, refresh option pool to 15%
    r3 = cap.execute_round(RoundConfig(
        name="Series A",
        pre_money_valuation=38_000_000,
        investment_amount=12_000_000,
        new_option_pool_pct=0.15,
        option_pool_pre_round=True,
        lead_investor_name="Series A Fund",
    ))
    rounds.append(r3)

    # Round 4: Series B — $25M at $95M pre, refresh pool to 12%
    r4 = cap.execute_round(RoundConfig(
        name="Series B",
        pre_money_valuation=95_000_000,
        investment_amount=25_000_000,
        new_option_pool_pct=0.12,
        option_pool_pre_round=True,
        lead_investor_name="Series B Fund",
    ))
    rounds.append(r4)

    # Round 5: Series C — $40M at $185M pre, refresh pool to 10%
    r5 = cap.execute_round(RoundConfig(
        name="Series C",
        pre_money_valuation=185_000_000,
        investment_amount=40_000_000,
        new_option_pool_pct=0.10,
        option_pool_pre_round=True,
        lead_investor_name="Series C Fund",
    ))
    rounds.append(r5)

    return cap, rounds


# ---------------------------------------------------------------------------
# Entry point
# ---------------------------------------------------------------------------

def main() -> None:
    parser = argparse.ArgumentParser(description="Fundraising Model — Cap Table & Dilution")
    parser.add_argument("--exit", type=float, default=250.0,
                        help="Exit valuation in $M for return analysis (default: 250)")
    parser.add_argument("--csv", action="store_true", help="Export round data as CSV to stdout")
    args = parser.parse_args()

    exit_valuation = args.exit * 1_000_000

    print("\n" + "="*70)
    print("  FUNDRAISING MODEL — CAP TABLE & DILUTION ANALYSIS")
    print("  Sample Company: Two-founder SaaS startup")
    print("  Pre-seed → Seed → Series A → Series B → Series C")
    print("="*70)

    cap, rounds = build_sample_model()

    # Print each round
    prev = None
    for r in rounds:
        print_round_result(r, prev)
        prev = r.cap_table

    # Dilution summary table
    print_dilution_summary(rounds)

    # Exit analysis at specified valuation
    exit_results = cap.analyze_exit(exit_valuation)
    print_exit_analysis(exit_results, exit_valuation)

    # Also print at 2x and 5x for sensitivity
    print("\n  Exit Sensitivity — Founder A Proceeds:")
    print(f"  {'Exit Valuation':<20} {'Founder A %':>12} {'Founder A $':>14} {'MOIC':>8}")
    print("  " + "-"*56)
    for mult in [0.5, 1.0, 1.5, 2.0, 3.0, 5.0]:
        val = rounds[-1].post_money_valuation * mult
        ex = cap.analyze_exit(val)
        founder_a = next((r for r in ex if r.shareholder == "Founder A (CEO)"), None)
        if founder_a:
            print(f"  {fmt(val):<20} {founder_a.ownership_pct*100:>11.2f}% "
                  f"{fmt(founder_a.proceeds_common):>14}  {'n/a':>8}")

    print("\n  Key Takeaways:")
    final = rounds[-1].cap_table
    total = sum(e.shares for e in final)
    founder_a_final = next((e for e in final if e.name == "Founder A (CEO)"), None)
    if founder_a_final:
        print(f"    Founder A final ownership: {founder_a_final.pct_ownership*100:.2f}%")
    total_raised = sum(e.invested for e in final)
    print(f"    Total capital raised:      {fmt(total_raised)}")
    print(f"    Total shares outstanding:  {total:,.0f}")
    print(f"    Final post-money:          {fmt(rounds[-1].post_money_valuation)}")
    print("\n    Run with --exit <$M> to model proceeds at different exit valuations.")
    print("    Example: python fundraising_model.py --exit 500")

    if args.csv:
        print("\n\n--- CSV EXPORT ---\n")
        sys.stdout.write(export_csv_rounds(rounds))


if __name__ == "__main__":
    main()

#!/usr/bin/env python3
"""
Unit Economics Analyzer
========================
Per-cohort LTV, per-channel CAC, payback periods, and LTV:CAC ratios.
Never blended averages — those hide what's actually happening.

Usage:
    python unit_economics_analyzer.py
    python unit_economics_analyzer.py --csv

Stdlib only. No dependencies.
"""

import argparse
import csv
import io
import sys
from dataclasses import dataclass, field
from typing import Optional


# ---------------------------------------------------------------------------
# Data structures
# ---------------------------------------------------------------------------

@dataclass
class CohortData:
    """
    Revenue data for a group of customers acquired in the same period.
    Revenue is tracked monthly: revenue[0] = month 1, revenue[1] = month 2, etc.
    """
    label: str                      # e.g. "Q1 2024"
    acquisition_period: str         # human-readable label
    customers_acquired: int
    total_cac_spend: float          # total S&M spend to acquire this cohort
    monthly_revenue: list[float]    # revenue per month from this cohort
    gross_margin_pct: float = 0.70  # blended gross margin for this cohort


@dataclass
class ChannelData:
    """Acquisition cost and customer data for a single channel."""
    channel: str
    spend: float
    customers_acquired: int
    avg_arpa: float                 # average revenue per account (monthly)
    gross_margin_pct: float = 0.70
    avg_monthly_churn: float = 0.02 # monthly churn rate for customers from this channel


@dataclass
class UnitEconomicsResult:
    """Computed unit economics for a cohort or channel."""
    label: str
    customers: int
    cac: float
    arpa: float                 # average revenue per account per month
    gross_margin_pct: float
    monthly_churn: float
    ltv: float
    ltv_cac_ratio: float
    payback_months: float
    # Cohort-specific
    m1_revenue: Optional[float] = None
    m6_revenue: Optional[float] = None
    m12_revenue: Optional[float] = None
    m24_revenue: Optional[float] = None
    m12_ltv: Optional[float] = None   # realized LTV through month 12
    retention_m6: Optional[float] = None    # % of M1 revenue retained at M6
    retention_m12: Optional[float] = None


# ---------------------------------------------------------------------------
# Calculators
# ---------------------------------------------------------------------------

def calc_ltv(arpa: float, gross_margin_pct: float, monthly_churn: float) -> float:
    """
    LTV = (ARPA × Gross Margin) / Monthly Churn Rate
    Assumes constant churn (simplified; cohort method is more accurate).
    """
    if monthly_churn <= 0:
        return float("inf")
    return (arpa * gross_margin_pct) / monthly_churn


def calc_payback(cac: float, arpa: float, gross_margin_pct: float) -> float:
    """
    CAC Payback (months) = CAC / (ARPA × Gross Margin)
    """
    denominator = arpa * gross_margin_pct
    if denominator <= 0:
        return float("inf")
    return cac / denominator


def analyze_cohort(cohort: CohortData) -> UnitEconomicsResult:
    """Compute full unit economics for a cohort."""
    n = cohort.customers_acquired
    if n == 0:
        raise ValueError(f"Cohort {cohort.label}: customers_acquired cannot be 0")

    cac = cohort.total_cac_spend / n

    # ARPA from month 1 revenue
    m1_rev = cohort.monthly_revenue[0] if cohort.monthly_revenue else 0
    arpa = m1_rev / n if n > 0 else 0

    # Observed monthly churn from cohort data
    # Use revenue decline from M1 to M12 to estimate churn
    months_available = len(cohort.monthly_revenue)
    if months_available >= 12:
        m12_rev = cohort.monthly_revenue[11]
        # Revenue retention over 12 months: (M12/M1)^(1/11) per month on average
        # Implied monthly retention rate
        if m1_rev > 0 and m12_rev > 0:
            monthly_retention = (m12_rev / m1_rev) ** (1 / 11)
            monthly_churn = 1 - monthly_retention
        else:
            monthly_churn = 0.02  # default
    elif months_available >= 6:
        m6_rev = cohort.monthly_revenue[5]
        if m1_rev > 0 and m6_rev > 0:
            monthly_retention = (m6_rev / m1_rev) ** (1 / 5)
            monthly_churn = 1 - monthly_retention
        else:
            monthly_churn = 0.02
    else:
        monthly_churn = 0.02  # default if < 6 months data

    # Clamp to reasonable range
    monthly_churn = max(0.001, min(monthly_churn, 0.30))

    ltv = calc_ltv(arpa, cohort.gross_margin_pct, monthly_churn)
    payback = calc_payback(cac, arpa, cohort.gross_margin_pct)
    ltv_cac = ltv / cac if cac > 0 else float("inf")

    # Snapshot revenues
    def rev_at(month_idx: int) -> Optional[float]:
        if months_available > month_idx:
            return cohort.monthly_revenue[month_idx]
        return None

    m6 = rev_at(5)
    m12 = rev_at(11)
    m24 = rev_at(23)

    # Realized LTV through observed months (actual gross profit)
    m12_ltv = sum(cohort.monthly_revenue[:12]) * cohort.gross_margin_pct if months_available >= 12 else None

    # Retention rates
    ret_m6 = (m6 / m1_rev) if (m6 is not None and m1_rev > 0) else None
    ret_m12 = (m12 / m1_rev) if (m12 is not None and m1_rev > 0) else None

    return UnitEconomicsResult(
        label=cohort.label,
        customers=n,
        cac=cac,
        arpa=arpa,
        gross_margin_pct=cohort.gross_margin_pct,
        monthly_churn=monthly_churn,
        ltv=ltv,
        ltv_cac_ratio=ltv_cac,
        payback_months=payback,
        m1_revenue=m1_rev,
        m6_revenue=m6,
        m12_revenue=m12,
        m24_revenue=m24,
        m12_ltv=m12_ltv,
        retention_m6=ret_m6,
        retention_m12=ret_m12,
    )


def analyze_channel(ch: ChannelData) -> UnitEconomicsResult:
    """Compute unit economics for an acquisition channel."""
    if ch.customers_acquired == 0:
        raise ValueError(f"Channel {ch.channel}: customers_acquired cannot be 0")

    cac = ch.spend / ch.customers_acquired
    ltv = calc_ltv(ch.avg_arpa, ch.gross_margin_pct, ch.avg_monthly_churn)
    payback = calc_payback(cac, ch.avg_arpa, ch.gross_margin_pct)
    ltv_cac = ltv / cac if cac > 0 else float("inf")

    return UnitEconomicsResult(
        label=ch.channel,
        customers=ch.customers_acquired,
        cac=cac,
        arpa=ch.avg_arpa,
        gross_margin_pct=ch.gross_margin_pct,
        monthly_churn=ch.avg_monthly_churn,
        ltv=ltv,
        ltv_cac_ratio=ltv_cac,
        payback_months=payback,
    )


# ---------------------------------------------------------------------------
# Blended metrics (for comparison)
# ---------------------------------------------------------------------------

def blended_cac(channels: list[ChannelData]) -> float:
    total_spend = sum(c.spend for c in channels)
    total_customers = sum(c.customers_acquired for c in channels)
    return total_spend / total_customers if total_customers > 0 else 0


def blended_ltv(channels: list[ChannelData]) -> float:
    """Weighted average LTV by customers acquired."""
    total_customers = sum(c.customers_acquired for c in channels)
    if total_customers == 0:
        return 0
    weighted = sum(
        calc_ltv(c.avg_arpa, c.gross_margin_pct, c.avg_monthly_churn) * c.customers_acquired
        for c in channels
    )
    return weighted / total_customers


# ---------------------------------------------------------------------------
# Reporting
# ---------------------------------------------------------------------------

def fmt(value: float, prefix: str = "$", decimals: int = 0) -> str:
    if value == float("inf"):
        return "∞"
    if abs(value) >= 1_000_000:
        return f"{prefix}{value/1_000_000:.2f}M"
    if abs(value) >= 1_000:
        return f"{prefix}{value/1_000:.1f}K"
    return f"{prefix}{value:.{decimals}f}"


def pct(value: Optional[float]) -> str:
    if value is None:
        return "n/a"
    return f"{value*100:.1f}%"


def rating(ltv_cac: float, payback: float) -> str:
    if ltv_cac == float("inf"):
        return "∞"
    if ltv_cac >= 5 and payback <= 12:
        return "🟢 Excellent"
    if ltv_cac >= 3 and payback <= 18:
        return "🟡 Good"
    if ltv_cac >= 2 and payback <= 24:
        return "🟠 Marginal"
    return "🔴 Poor"


def print_cohort_analysis(results: list[UnitEconomicsResult]) -> None:
    print("\n" + "="*80)
    print("  COHORT ANALYSIS")
    print("="*80)
    print(f"  {'Cohort':<12} {'Cust':>5} {'CAC':>8} {'ARPA/mo':>9} {'Churn/mo':>10} "
          f"{'LTV':>10} {'LTV:CAC':>8} {'Payback':>9} {'Ret@M12':>8}")
    print("  " + "-"*88)
    for r in results:
        payback_str = f"{r.payback_months:.1f}mo" if r.payback_months != float("inf") else "∞"
        ltv_str = fmt(r.ltv) if r.ltv != float("inf") else "∞"
        ltv_cac_str = f"{r.ltv_cac_ratio:.1f}x" if r.ltv_cac_ratio != float("inf") else "∞"
        print(
            f"  {r.label:<12} {r.customers:>5} {fmt(r.cac):>8} {fmt(r.arpa):>9} "
            f"{pct(r.monthly_churn):>10} {ltv_str:>10} {ltv_cac_str:>8} "
            f"{payback_str:>9} {pct(r.retention_m12):>8}"
        )

    # Trend analysis
    print("\n  Cohort Trend (is the business getting better or worse?):")
    if len(results) >= 3:
        ltv_cac_values = [r.ltv_cac_ratio for r in results if r.ltv_cac_ratio != float("inf")]
        cac_values = [r.cac for r in results]
        churn_values = [r.monthly_churn for r in results]

        if len(ltv_cac_values) >= 2:
            ltv_cac_trend = "↑ Improving" if ltv_cac_values[-1] > ltv_cac_values[0] else "↓ Deteriorating"
        else:
            ltv_cac_trend = "n/a"

        cac_trend = "↓ Decreasing (good)" if cac_values[-1] < cac_values[0] else "↑ Increasing"
        churn_trend = "↓ Improving" if churn_values[-1] < churn_values[0] else "↑ Worsening"

        print(f"    LTV:CAC:    {ltv_cac_trend}")
        print(f"    CAC:        {cac_trend}")
        print(f"    Churn rate: {churn_trend}")


def print_channel_analysis(results: list[UnitEconomicsResult], channels: list[ChannelData]) -> None:
    print("\n" + "="*80)
    print("  CHANNEL ANALYSIS (Per-Channel vs Blended)")
    print("="*80)
    print(f"  {'Channel':<22} {'Spend':>9} {'Cust':>5} {'CAC':>8} {'LTV':>10} {'LTV:CAC':>8} {'Payback':>9} {'Rating'}")
    print("  " + "-"*90)
    for r, ch in zip(results, channels):
        payback_str = f"{r.payback_months:.1f}mo" if r.payback_months != float("inf") else "∞"
        ltv_str = fmt(r.ltv) if r.ltv != float("inf") else "∞"
        ltv_cac_str = f"{r.ltv_cac_ratio:.1f}x" if r.ltv_cac_ratio != float("inf") else "∞"
        print(
            f"  {r.label:<22} {fmt(ch.spend):>9} {r.customers:>5} {fmt(r.cac):>8} "
            f"{ltv_str:>10} {ltv_cac_str:>8} {payback_str:>9}  {rating(r.ltv_cac_ratio, r.payback_months)}"
        )

    # Blended comparison
    b_cac = blended_cac(channels)
    b_ltv = blended_ltv(channels)
    b_ltv_cac = b_ltv / b_cac if b_cac > 0 else 0
    total_spend = sum(c.spend for c in channels)
    total_customers = sum(c.customers_acquired for c in channels)
    avg_payback = sum(
        calc_payback(b_cac, c.avg_arpa, c.gross_margin_pct) * c.customers_acquired
        for c in channels
    ) / total_customers

    print("  " + "-"*90)
    print(
        f"  {'BLENDED (dangerous)':<22} {fmt(total_spend):>9} {total_customers:>5} "
        f"{fmt(b_cac):>8} {fmt(b_ltv):>10} {b_ltv_cac:.1f}x{'':<7} "
        f"{avg_payback:.1f}mo{'':<4}  {rating(b_ltv_cac, avg_payback)}"
    )
    print("\n  ⚠️  Blended numbers hide channel-level problems. Manage channels individually.")

    # Budget reallocation
    print("\n  Recommended Budget Reallocation:")
    sorted_results = sorted(zip(results, channels), key=lambda x: x[0].ltv_cac_ratio, reverse=True)
    for r, ch in sorted_results:
        if r.ltv_cac_ratio >= 3:
            action = "✅ Scale"
        elif r.ltv_cac_ratio >= 2:
            action = "🔄 Optimize"
        else:
            action = "❌ Cut / pause"
        print(f"    {ch.channel:<22} LTV:CAC = {r.ltv_cac_ratio:.1f}x  → {action}")


def export_csv_results(cohort_results: list[UnitEconomicsResult], channel_results: list[UnitEconomicsResult]) -> str:
    buf = io.StringIO()
    writer = csv.writer(buf)
    writer.writerow(["Type", "Label", "Customers", "CAC", "ARPA_Monthly", "Gross_Margin_Pct",
                     "Monthly_Churn", "LTV", "LTV_CAC_Ratio", "Payback_Months",
                     "Retention_M6", "Retention_M12"])
    for r in cohort_results:
        writer.writerow(["cohort", r.label, r.customers, round(r.cac, 2), round(r.arpa, 2),
                         r.gross_margin_pct, round(r.monthly_churn, 4),
                         round(r.ltv, 2) if r.ltv != float("inf") else "inf",
                         round(r.ltv_cac_ratio, 2) if r.ltv_cac_ratio != float("inf") else "inf",
                         round(r.payback_months, 2) if r.payback_months != float("inf") else "inf",
                         round(r.retention_m6, 3) if r.retention_m6 else "",
                         round(r.retention_m12, 3) if r.retention_m12 else ""])
    for r in channel_results:
        writer.writerow(["channel", r.label, r.customers, round(r.cac, 2), round(r.arpa, 2),
                         r.gross_margin_pct, round(r.monthly_churn, 4),
                         round(r.ltv, 2) if r.ltv != float("inf") else "inf",
                         round(r.ltv_cac_ratio, 2) if r.ltv_cac_ratio != float("inf") else "inf",
                         round(r.payback_months, 2) if r.payback_months != float("inf") else "inf",
                         "", ""])
    return buf.getvalue()


# ---------------------------------------------------------------------------
# Sample data
# ---------------------------------------------------------------------------

def make_sample_cohorts() -> list[CohortData]:
    """
    Series A SaaS company, 8 quarters of cohort data.
    Shows a business improving on all dimensions over time.
    """
    return [
        CohortData(
            label="Q1 2023", acquisition_period="Jan-Mar 2023",
            customers_acquired=12, total_cac_spend=54_000,
            gross_margin_pct=0.68,
            monthly_revenue=[
                10_200, 9_600, 9_100, 8_700, 8_300, 8_000,  # M1-M6
                7_800, 7_600, 7_400, 7_200, 7_000, 6_800,   # M7-M12
                6_700, 6_600, 6_500, 6_400, 6_300, 6_200,   # M13-M18
                6_100, 6_000, 5_900, 5_800, 5_700, 5_600,   # M19-M24
            ],
        ),
        CohortData(
            label="Q2 2023", acquisition_period="Apr-Jun 2023",
            customers_acquired=15, total_cac_spend=60_000,
            gross_margin_pct=0.69,
            monthly_revenue=[
                13_500, 12_900, 12_500, 12_100, 11_800, 11_500,
                11_300, 11_100, 10_900, 10_700, 10_500, 10_300,
                10_200, 10_100, 10_000, 9_900, 9_800, 9_700,
            ],
        ),
        CohortData(
            label="Q3 2023", acquisition_period="Jul-Sep 2023",
            customers_acquired=18, total_cac_spend=63_000,
            gross_margin_pct=0.70,
            monthly_revenue=[
                16_200, 15_800, 15_400, 15_100, 14_800, 14_600,
                14_400, 14_200, 14_000, 13_900, 13_800, 13_700,
                13_600, 13_500, 13_400, 13_300,
            ],
        ),
        CohortData(
            label="Q4 2023", acquisition_period="Oct-Dec 2023",
            customers_acquired=22, total_cac_spend=70_400,
            gross_margin_pct=0.71,
            monthly_revenue=[
                20_900, 20_500, 20_200, 19_900, 19_700, 19_500,
                19_300, 19_100, 19_000, 18_900, 18_800, 18_700,
            ],
        ),
        CohortData(
            label="Q1 2024", acquisition_period="Jan-Mar 2024",
            customers_acquired=28, total_cac_spend=81_200,
            gross_margin_pct=0.72,
            monthly_revenue=[
                27_200, 26_900, 26_600, 26_400, 26_200, 26_000,
                25_800, 25_700, 25_600, 25_500,
            ],
        ),
        CohortData(
            label="Q2 2024", acquisition_period="Apr-Jun 2024",
            customers_acquired=34, total_cac_spend=91_800,
            gross_margin_pct=0.72,
            monthly_revenue=[
                33_300, 33_000, 32_800, 32_600, 32_400, 32_200,
            ],
        ),
        CohortData(
            label="Q3 2024", acquisition_period="Jul-Sep 2024",
            customers_acquired=40, total_cac_spend=100_000,
            gross_margin_pct=0.73,
            monthly_revenue=[
                39_600, 39_400, 39_200,
            ],
        ),
        CohortData(
            label="Q4 2024", acquisition_period="Oct-Dec 2024",
            customers_acquired=47, total_cac_spend=112_800,
            gross_margin_pct=0.73,
            monthly_revenue=[
                47_000,
            ],
        ),
    ]


def make_sample_channels() -> list[ChannelData]:
    """
    Q4 2024 channel breakdown. Blended looks fine; per-channel reveals problems.
    """
    return [
        ChannelData("Organic / SEO",     spend=9_500,  customers_acquired=14, avg_arpa=950,  gross_margin_pct=0.73, avg_monthly_churn=0.015),
        ChannelData("Paid Search (SEM)",  spend=48_000, customers_acquired=18, avg_arpa=980,  gross_margin_pct=0.73, avg_monthly_churn=0.020),
        ChannelData("Paid Social",        spend=32_000, customers_acquired=8,  avg_arpa=900,  gross_margin_pct=0.72, avg_monthly_churn=0.025),
        ChannelData("Content / Inbound",  spend=11_000, customers_acquired=6,  avg_arpa=1100, gross_margin_pct=0.74, avg_monthly_churn=0.012),
        ChannelData("Outbound SDR",       spend=22_000, customers_acquired=4,  avg_arpa=1200, gross_margin_pct=0.73, avg_monthly_churn=0.022),
        ChannelData("Events / Webinars",  spend=18_500, customers_acquired=3,  avg_arpa=1050, gross_margin_pct=0.72, avg_monthly_churn=0.028),
        ChannelData("Partner / Referral", spend=7_800,  customers_acquired=7,  avg_arpa=1000, gross_margin_pct=0.73, avg_monthly_churn=0.013),
    ]


# ---------------------------------------------------------------------------
# Entry point
# ---------------------------------------------------------------------------

def main() -> None:
    parser = argparse.ArgumentParser(description="Unit Economics Analyzer")
    parser.add_argument("--csv", action="store_true", help="Export results as CSV to stdout")
    args = parser.parse_args()

    cohorts = make_sample_cohorts()
    channels = make_sample_channels()

    print("\n" + "="*80)
    print("  UNIT ECONOMICS ANALYZER")
    print("  Sample Company: Series A SaaS | Q4 2024 Snapshot")
    print("  Gross Margin: ~72% | Monthly Churn: derived from cohort data")
    print("="*80)

    cohort_results = [analyze_cohort(c) for c in cohorts]
    channel_results = [analyze_channel(c) for c in channels]

    print_cohort_analysis(cohort_results)
    print_channel_analysis(channel_results, channels)

    # Health summary
    print("\n" + "="*80)
    print("  HEALTH SUMMARY")
    print("="*80)
    latest = cohort_results[-1]
    prev = cohort_results[-4] if len(cohort_results) >= 4 else cohort_results[0]

    print(f"\n  Latest Cohort ({latest.label}):")
    print(f"    CAC:          {fmt(latest.cac)}")
    ltv_str = fmt(latest.ltv) if latest.ltv != float("inf") else "∞"
    ltv_cac_str = f"{latest.ltv_cac_ratio:.1f}x" if latest.ltv_cac_ratio != float("inf") else "∞"
    payback_str = f"{latest.payback_months:.1f} months" if latest.payback_months != float("inf") else "∞"
    print(f"    LTV:          {ltv_str}")
    print(f"    LTV:CAC:      {ltv_cac_str}  (target: > 3x)")
    print(f"    CAC Payback:  {payback_str}  (target: < 18mo)")
    print(f"    Rating:       {rating(latest.ltv_cac_ratio, latest.payback_months)}")

    # Trend vs 4 quarters ago
    print(f"\n  Trend vs {prev.label}:")
    cac_delta = (latest.cac - prev.cac) / prev.cac * 100
    ltv_delta_str = "n/a"
    if latest.ltv != float("inf") and prev.ltv != float("inf"):
        ltv_delta = (latest.ltv - prev.ltv) / prev.ltv * 100
        ltv_delta_str = f"{ltv_delta:+.1f}%"
    cac_str = "↓ Better" if cac_delta < 0 else "↑ Worse"
    print(f"    CAC:    {cac_delta:+.1f}%  ({cac_str})")
    print(f"    LTV:    {ltv_delta_str}")

    print("\n  Benchmark Reference:")
    print("    LTV:CAC > 5x  → Scale aggressively")
    print("    LTV:CAC 3-5x  → Healthy; grow at current pace")
    print("    LTV:CAC 2-3x  → Marginal; optimize before scaling")
    print("    LTV:CAC < 2x  → Acquiring unprofitably; stop and fix")
    print("    Payback < 12mo → Outstanding capital efficiency")
    print("    Payback 12-18mo → Good for B2B SaaS")
    print("    Payback > 24mo → Requires long-dated capital to scale")

    if args.csv:
        print("\n\n--- CSV EXPORT ---\n")
        sys.stdout.write(export_csv_results(cohort_results, channel_results))


if __name__ == "__main__":
    main()