/**
 * Dogfood (#31): run CommiTea's own deterministic engine against the live
 * christian/commitea backlog and print the project report each screen derives —
 * board, critical path, schedule, Monte Carlo forecast, per-milestone runway.
 *
 * This is the core brain (schedule + forecast + capacity), the exact code the
 * desktop app runs. Read-only. Run:  yarn tsx scripts/dogfood-report.ts
 */
import { readFileSync } from 'node:fs'
import { dirname, join } from 'node:path'
import { fileURLToPath } from 'node:url'

import {
  createGiteaClient,
  forecast,
  inferLifecycle,
  parseCapacityConfig,
  capacityPerWorkday,
  schedule,
  type GiteaIssue,
  type DependencyEdge,
  type Worker,
} from '@commitea/core'

const here = dirname(fileURLToPath(import.meta.url))

function token(): string {
  let dir = here
  for (let i = 0; i < 6; i++) {
    try {
      const m = /^GITEA_TOKEN\s*=\s*(.+?)\s*$/m.exec(readFileSync(join(dir, '.env.local'), 'utf8'))
      if (m) return m[1].trim()
    } catch {
      /* keep walking up */
    }
    dir = dirname(dir)
  }
  throw new Error('no GITEA_TOKEN in any .env.local up the tree')
}

/** working-day offset → calendar date (skip Sat/Sun), then a short label. */
function addWorkingDays(base: Date, n: number): Date {
  const d = new Date(base)
  let left = Math.ceil(n)
  while (left > 0) {
    d.setDate(d.getDate() + 1)
    const day = d.getDay()
    if (day !== 0 && day !== 6) left--
  }
  return d
}
const fmt = (d: Date) => d.toLocaleDateString('en-US', { month: 'short', day: 'numeric' })

async function main() {
  const client = createGiteaClient(
    { baseUrl: 'https://gitea.stephenmann.io', owner: 'christian', repo: 'commitea', token: token() },
    fetch,
  )

  const all = await client.listIssues({ state: 'all' })
  const open = all.filter((i) => i.state === 'open')
  const closed = all.filter((i) => i.state === 'closed')

  // Real dependency edges (open issues only — the scheduler drops out-of-scope endpoints anyway).
  const edges: DependencyEdge[] = []
  for (const i of open) {
    for (const dep of await client.getIssueDependencies(i.number)) edges.push({ issue: i.number, dependsOn: dep })
  }

  // Capacity lanes from the pm-state repo (a separate repo, exactly like the app's
  // pmStateClient — NOT the managed repo).
  const pmClient = createGiteaClient(
    { baseUrl: 'https://gitea.stephenmann.io', owner: 'christian', repo: 'commitea-pm-state', token: token() },
    fetch,
  )
  let workers: Worker[] = []
  try {
    const f = await pmClient.getFile('capacity/members.json')
    if (f) {
      const members = parseCapacityConfig(JSON.parse(Buffer.from(f.contentBase64, 'base64').toString('utf8')))
      workers = members.map((m) => ({ person: m.person, speed: capacityPerWorkday(m) }))
    }
  } catch {
    /* no capacity → single serial worker */
  }

  const toSchedulable = (issues: GiteaIssue[]) =>
    issues.map((i) => ({
      number: i.number,
      title: i.title,
      labels: i.labels,
      estimateDays: i.facts.estimateDays,
      priority: i.facts.priority,
      assignee: i.assignee,
    }))

  const plan = schedule(toSchedulable(open), edges)
  const today = new Date()
  const f = forecast(toSchedulable(open), edges, { workers })

  const bar = '─'.repeat(64)
  console.log(`\n${bar}\n CommiTea, on itself — ${fmt(today)} ${today.getFullYear()}\n${bar}`)
  console.log(` Board: ${open.length} open · ${closed.length} done`)
  console.log(` Team:  ${workers.length ? workers.map((w) => `${w.person} (${w.speed.toFixed(2)}/day)`).join(', ') : 'single serial worker'}`)
  const unassigned = open.filter((i) => !i.assignee).length
  if (unassigned) console.log(` ⚠  ${unassigned}/${open.length} open issues have no assignee`)

  console.log(`\n Schedule (dependency + priority order, ${workers.length || 1} lane${workers.length === 1 ? '' : 's'}):`)
  for (const it of plan.items) {
    const crit = it.critical ? ' ★crit' : ''
    const blocks = it.blocks.length ? `  blocks ${it.blocks.map((b) => '#' + b).join(',')}` : ''
    console.log(
      `  #${String(it.number).padEnd(3)} ${fmt(addWorkingDays(today, it.startDay))}→${fmt(addWorkingDays(today, it.endDay))}${crit.padEnd(7)} ${it.title.slice(0, 40)}${blocks}`,
    )
  }
  if (plan.cycle) console.log(`  ⚠ dependency cycle: ${plan.cycle.join(' → ')}`)

  const p90 = f.curve.length ? f.curve[f.curve.length - 1].p90Day : f.p95Day
  console.log(`\n Forecast (Monte Carlo, ${f.trials} trials, ${f.coldStart ? 'cold-start priors' : 'fitted'}):`)
  console.log(`  whole backlog lands  p50 ${fmt(addWorkingDays(today, f.p50Day))} · p80 ${fmt(addWorkingDays(today, f.p80Day))} · p90 ${fmt(addWorkingDays(today, p90))}`)

  // Per-milestone runway.
  const ms = await client.listMilestones()
  console.log(`\n Runway (per open milestone):`)
  for (const m of ms.filter((x) => x.state === 'open')) {
    const scope = open.filter((i) => i.milestone?.id === m.id)
    if (!scope.length) continue
    const mf = forecast(toSchedulable(scope), edges, { workers })
    const mp90 = mf.curve.length ? mf.curve[mf.curve.length - 1].p90Day : mf.p95Day
    const due = m.dueOn ? fmt(new Date(m.dueOn)) : 'no due date'
    console.log(
      `  ${m.title.padEnd(28)} ${scope.length} open · p50 ${fmt(addWorkingDays(today, mf.p50Day))}–p90 ${fmt(addWorkingDays(today, mp90))}  (due: ${due})`,
    )
  }
  console.log(`\n${bar}\n`)
}

main().catch((e) => {
  console.error(e)
  process.exit(1)
})