/**
 * Pure helpers for the per-worktree environment provisioning in
 * `scripts/worktree.mjs` — deterministic port + database names derived from
 * the branch, so parallel agents (each in their own worktree) never fight
 * over port 3000, the shared `teqo_test` database, or a second Postgres
 * container on 5432.
 *
 * Contract: `slot` is the single collision domain. Port and BOTH database
 * names derive from the final slot, so a bumped slot frees all three at
 * once. Deterministic for a given (branch, code, live taken-slots set) —
 * the same "depends on live state" determinism the claim-queue branch picker
 * already has.
 */

/** Dev-server ports start here: slot 15 → http://localhost:3115. */
export const DEV_PORT_BASE = 3100

/** Marker line identifying a generated env file (never overwrite manual ones). */
export const GENERATED_ENV_MARKER = '# teqo worktree env (generated by pnpm worktree next)'

/** Slot cap — ports above 3100 + 999 would leave the usual ephemeral range. */
const MAX_SLOT = 999

/** First run of digits in the issue code (`C15` → 15, `B164` → 164); null when none. */
export const numericSlotOfCode = (code) => {
  const match = /([0-9]+)/.exec(code ?? '')
  return match ? Number(match[1]) : null
}

/** Stable 32-bit FNV-1a hash → slot in [0, MAX_SLOT] for codes without digits. */
export const hashSlotOf = (value) => {
  let hash = 0x811c9dc5
  for (const byte of Buffer.from(String(value), 'utf8')) {
    hash ^= byte
    hash = Math.imul(hash, 0x01000193) >>> 0
  }
  return hash % (MAX_SLOT + 1)
}

/** The slot a branch prefers before collision resolution. */
const preferredSlotForBranch = (branch, code) => {
  const numeric = numericSlotOfCode(code)
  return numeric !== null && numeric <= MAX_SLOT ? numeric : hashSlotOf(branch)
}

export const devPortForSlot = (slot) => DEV_PORT_BASE + slot
export const devDatabaseForSlot = (slot) => `teqo_wt${slot}`
export const testDatabaseForSlot = (slot) => `teqo_wt${slot}_test`

/** DB name charset guard — derived names are fed into `CREATE DATABASE` SQL. */
export const isGeneratedDatabaseName = (name) => /^teqo_wt[0-9]+(_test)?$/.test(name ?? '')

/**
 * Final environment for a branch. `takenSlots` = slots already claimed by
 * OTHER live worktrees; bumps +1 until free (bounded — live slot sets are
 * tiny). Every value a consumer needs derives from the one final slot.
 */
export const worktreeEnvironment = ({ branch, code, takenSlots = new Set() }) => {
  let slot = preferredSlotForBranch(branch, code)
  while (takenSlots.has(slot)) slot += 1
  return {
    slot,
    devPort: devPortForSlot(slot),
    devDatabase: devDatabaseForSlot(slot),
    testDatabase: testDatabaseForSlot(slot),
  }
}

/**
 * Line arrays for `.env.local` (dev) and `.env.test.local` (test) of a
 * provisioned worktree. `NEXT_PUBLIC_SITE_URL` and `PLAYWRIGHT_BASE_URL` must
 * point BOTH files at the SAME slot port — the parity is what keeps a parallel
 * e2e run in another worktree from falling back to port 3000 (OPS20: they had
 * drifted — the dev file carried PLAYWRIGHT_BASE_URL, the test file didn't, and
 * playwright.config.ts only reads `.env.test.local`). Building both from one
 * `url` makes the drift structurally impossible.
 *
 * @param {{ branch: string, issueLabel?: string, generatedBy: string, env: { slot: number, devPort: number, devDatabase: string, testDatabase: string }, payloadSecret: string, copiedLines?: string[] }} options
 * @returns {{ dev: string[], test: string[] }}
 */
export const worktreeEnvFileContents = ({
  branch,
  issueLabel = '',
  generatedBy,
  env,
  payloadSecret,
  copiedLines = [],
}) => {
  // Both DATABASE_URLs derive from the same slot as the port (module contract).
  const devUrl = `postgresql://teqo:teqo@localhost:5432/${env.devDatabase}`
  const testUrl = `postgresql://teqo:teqo@localhost:5432/${env.testDatabase}`
  const url = `http://localhost:${env.devPort}`
  const header = [
    GENERATED_ENV_MARKER,
    `# branch ${branch}${issueLabel} · slot ${env.slot} — ${generatedBy}`,
  ]
  return {
    dev: [
      ...header,
      `DATABASE_URL=${devUrl}`,
      `PORT=${env.devPort}`,
      `NEXT_PUBLIC_SITE_URL=${url}`,
      `PLAYWRIGHT_BASE_URL=${url}`,
      `PAYLOAD_SECRET=${payloadSecret}`,
      ...copiedLines,
      '',
    ],
    test: [
      ...header,
      '# Lido DEPOIS de .env.test (vitest.setup.ts / playwright.config.ts) — suites isoladas.',
      `DATABASE_URL=${testUrl}`,
      `NEXT_PUBLIC_SITE_URL=${url}`,
      `PLAYWRIGHT_BASE_URL=${url}`,
      '',
    ],
  }
}