// OTIVM server — OTIVM-IV
// Per-player SQLite integration.
// TESSERA world database (data/otivm.sqlite3) — read-only, unchanged.
// Player databases (data/saves/{token}.sqlite3) — one per player,
//   write-safe (single writer), created from data/create_player_db.sql
//   on first access.
// JSON save files (data/saves/{token}.json) — never deleted, migrated
//   transparently on first SQLite access if present.
// Frontend interface unchanged — GET/POST /api/save/:token same as before.
//
// Change 1 (OTIVM-IV): on dispatch_start event, create ventures +
//   venture_legs rows. On dispatch_complete, close venture with outcome_net.
// Change 2 (OTIVM-IV): on den change, write parameter_drift_log row
//   (trigger_type = 'venture_complete'). On aut change, write
//   parameter_drift_log row (trigger_type = 'interval_complete').
//
// Cost split — placeholder pending a proper cost model:
//   cost_vectura  = 60% of route cost  (VECTVRA — freight charge)
//   cost_portoria = 25% of route cost  (PORTORIUM — customs duty)
//   cost_other    = 15% of route cost  (horreum, incidentals)
// These proportions are fixed constants here, not in the schema.
// When a real cost model is designed, this is the only place to change.

import Fastify from 'fastify'
import fastifyStatic from '@fastify/static'
import { readFile, mkdir } from 'fs/promises'
import { join, dirname } from 'path'
import { fileURLToPath } from 'url'
import { existsSync } from 'fs'
import { readFileSync } from 'fs'
import Database from 'better-sqlite3'

const __dirname = dirname(fileURLToPath(import.meta.url))
const ROOT        = join(__dirname, '..')
const DIST        = join(ROOT, 'dist')
const SAVES_DIR   = join(ROOT, 'data', 'saves')
const DB_PATH     = join(ROOT, 'data', 'otivm.sqlite3')
const SCHEMA_PATH = join(ROOT, 'data', 'create_player_db.sql')

await mkdir(SAVES_DIR, { recursive: true })

// ── Cost split constants ─────────────────────────────────────────────────────
// Placeholder proportions — change here only when a real cost model is defined.
const COST_VECTURA_RATIO  = 0.60
const COST_PORTORIA_RATIO = 0.25
// cost_other = remainder (1 - 0.60 - 0.25 = 0.15)

// Route mode classification — used for venture_legs.mode
// 'olive' and 'wine' are road; 'grain', 'linen' are sea.
// Extend this map when new routes are added.
const ROUTE_MODE = {
  olive:  'road',
  wine:   'road',
  grain:  'sea',
  linen:  'sea',
}

// Route cargo definitions — used for ventures.cargo_type / cargo_unit
const ROUTE_CARGO = {
  olive: { type: 'Olive oil, Garum',         unit: 'amphora' },
  wine:  { type: 'Campanian wine, Wool',      unit: 'amphora' },
  grain: { type: 'Adriatic grain, Amber',     unit: 'modius'  },
  linen: { type: 'Berber linen, Frankincense',unit: 'talent'  },
}

// Route H3 waypoints — origin and destination res-5 cell IDs
// Sourced from src/constants.js WAYPOINTS and ROUTES
const ROUTE_H3 = {
  olive: { origin: '851e805bfffffff', destination: '851e8333fffffff' },
  wine:  { origin: '851e8333fffffff', destination: '851e8ba3fffffff' },
  grain: { origin: '851e8ba3fffffff', destination: '85386e23fffffff' },
  linen: { origin: '85386e23fffffff', destination: '853f5ba7fffffff' },
}

// Route cost and profit — sourced from src/constants.js ROUTES
// Duplicated here so server/index.js has no dependency on frontend constants.
const ROUTE_ECONOMICS = {
  olive: { cost: 8,  profit: 12, duration_ms: 6000  },
  wine:  { cost: 14, profit: 22, duration_ms: 9000  },
  grain: { cost: 24, profit: 40, duration_ms: 12000 },
  linen: { cost: 38, profit: 70, duration_ms: 18000 },
}

// MS_PER_SIM_DAY — must match src/constants.js
const MS_PER_SIM_DAY = 3_000

// ── TESSERA world database (read-only) ──────────────────────────────────────

const db = new Database(DB_PATH, { readonly: true })

const stmtEpoch = db.prepare(
  'SELECT sl_offset_cm FROM paleo_epochs WHERE epoch_key = ?'
)

const stmtH7 = db.prepare(`
  SELECT
    h7,
    AVG(lat)                                                                   AS lat,
    AVG(lon)                                                                   AS lon,
    SUM(CASE WHEN elev_cm > ? THEN 1 ELSE 0 END)                               AS h7_land,
    COUNT(*)                                                                   AS h9_total
  FROM tessera_cells
  WHERE h5 = ? AND status = 2
  GROUP BY h7
`)

function h3HexToInt(hexStr) {
  return BigInt('0x' + hexStr)
}

// ── Per-player database ──────────────────────────────────────────────────────

const PLAYER_SCHEMA_SQL = readFileSync(SCHEMA_PATH, 'utf8')

function openPlayerDb(token) {
  const path = join(SAVES_DIR, `${token}.sqlite3`)
  const isNew = !existsSync(path)
  const pdb = new Database(path)
  pdb.pragma('journal_mode = WAL')
  pdb.pragma('foreign_keys = ON')
  if (isNew) {
    pdb.exec(PLAYER_SCHEMA_SQL)
  }
  return pdb
}

// ── UUID generator ───────────────────────────────────────────────────────────
// Simple RFC4122 v4 UUID — no external dependency needed.
function uuid() {
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, c => {
    const r = Math.random() * 16 | 0
    return (c === 'x' ? r : (r & 0x3 | 0x8)).toString(16)
  })
}

// ── JSON → SQLite migration ──────────────────────────────────────────────────

function migrateJsonToSqlite(token, pdb, json) {
  const now = new Date().toISOString()
  const actorId = token
  const sessionId = token

  const background = json.background_id || 'unknown'
  const name       = json.actor_name    || 'Mercator'
  const epoch      = 'roman_14bce'

  pdb.prepare(`
    INSERT OR IGNORE INTO actor_profile
      (actor_id, session_id, background_id, actor_name, epoch, schema_version, recorded_at)
    VALUES (?, ?, ?, ?, ?, 5, ?)
  `).run(actorId, sessionId, background, name, epoch, now)

  pdb.prepare(`
    INSERT OR IGNORE INTO actor_parameters
      (actor_id, parameter_token, scope, layer,
       value_true, value_perceived, value_social,
       confidence_tag, observable_level, drift_source, recorded_at)
    SELECT
      ?, parameter_token, 'actor',
      CASE WHEN parameter_token IN ('auctoritas','clientela','liquiditas','fama',
           'disciplina','mercatus_scientia','itineris_scientia','ius_accessus',
           'periculum_tolerantia','negotiatio','litterae','officia_burden')
           THEN 'roman' ELSE 'universal' END,
      value_true, value_perceived, NULL,
      confidence_tag, observable_level, 'migration', ?
    FROM background_starting_values
    WHERE background_id = ?
  `).run(actorId, now, background)

  if (json.den !== undefined) {
    pdb.prepare(`
      INSERT INTO actor_parameters
        (actor_id, parameter_token, scope, layer,
         value_true, value_perceived, confidence_tag, observable_level,
         drift_source, recorded_at)
      VALUES (?, 'liquiditas', 'actor', 'roman',
              ?, ?, 'measured', 'full', 'migration', ?)
    `).run(actorId, String(json.den), String(json.den), now)
  }

  if (json.aut !== undefined) {
    const band = autBand(json.aut)
    pdb.prepare(`
      INSERT INTO actor_parameters
        (actor_id, parameter_token, scope, layer,
         value_true, value_perceived, value_social,
         confidence_tag, observable_level, drift_source, recorded_at)
      VALUES (?, 'auctoritas', 'actor', 'roman',
              ?, ?, ?, 'indicated', 'partial', 'migration', ?)
    `).run(actorId, band, band, band, now)
  }

  const insertEvent = pdb.prepare(`
    INSERT INTO events (actor_id, event_type, ref_id, ref_type, payload, recorded_at)
    VALUES (?, ?, ?, ?, ?, ?)
  `)
  for (const ev of (json.events || [])) {
    insertEvent.run(
      actorId,
      ev.type || 'unknown',
      ev.route_id || null,
      ev.route_id ? 'venture' : null,
      JSON.stringify(ev),
      ev.timestamp_utc || now
    )
  }

  insertEvent.run(
    actorId, 'session_start', null, null,
    JSON.stringify({ source: 'json_migration', schema_version: 5 }),
    now
  )
}

function autBand(aut) {
  if (aut >= 30) return 'distinguished'
  if (aut >= 15) return 'high'
  if (aut >= 5)  return 'medium'
  return 'low'
}

// ── Read player state ────────────────────────────────────────────────────────

function readPlayerState(token, pdb) {
  const params = pdb.prepare(`
    SELECT parameter_token, value_true, value_perceived, value_social,
           confidence_tag, observable_level
    FROM actor_parameters
    WHERE actor_id = ? AND superseded_at IS NULL
    ORDER BY recorded_at DESC
  `).all(token)

  const paramMap = {}
  for (const p of params) {
    paramMap[p.parameter_token] = p
  }

  const den = parseInt(paramMap['liquiditas']?.value_true || '0', 10)
  const autStr = paramMap['auctoritas']?.value_true || 'low'
  const aut = autToInt(autStr)

  const events = pdb.prepare(`
    SELECT event_type AS type, ref_id AS route_id, payload, recorded_at AS timestamp_utc
    FROM events
    WHERE actor_id = ?
    ORDER BY recorded_at ASC
  `).all(token)

  let dispatches = 0
  const route_dispatches = {}
  const journal_seen = []
  let active_dispatch = null
  let chapter = 1

  for (const ev of events) {
    if (ev.type === 'dispatch_complete' && ev.route_id) {
      dispatches++
      route_dispatches[ev.route_id] = (route_dispatches[ev.route_id] || 0) + 1
    }
    if (ev.type === 'journal_unlock' && ev.route_id) {
      journal_seen.push({
        routeId: ev.route_id,
        dispatch: route_dispatches[ev.route_id] || 1,
      })
    }
    if (ev.type === 'venture_start' || ev.type === 'dispatch_start') {
      try {
        const p = JSON.parse(ev.payload || '{}')
        active_dispatch = {
          route_id:    ev.route_id || p.route_id,
          started_utc: ev.timestamp_utc,
          duration_ms: p.duration_ms || 0,
        }
      } catch { /* ignore malformed payload */ }
    }
    if (ev.type === 'venture_complete' || ev.type === 'dispatch_complete') {
      active_dispatch = null
    }
  }

  if (aut >= 30 && den >= 800) chapter = 5
  else if (aut >= 15 && den >= 350) chapter = 4
  else if (aut >= 5  && den >= 120) chapter = 3
  else if (den >= 40) chapter = 2

  const profile = pdb.prepare(
    'SELECT * FROM actor_profile WHERE actor_id = ? ORDER BY recorded_at DESC LIMIT 1'
  ).get(token)

  return {
    token,
    background_id:    profile?.background_id || 'unknown',
    actor_name:       profile?.actor_name    || 'Mercator',
    den,
    aut,
    chapter,
    dispatches,
    route_dispatches,
    journal_seen,
    active_dispatch,
    events: events.map(e => ({
      type:          e.type,
      route_id:      e.route_id,
      timestamp_utc: e.timestamp_utc,
    })),
    created_at: profile?.recorded_at || new Date().toISOString(),
    schema_version: 5,
  }
}

function autToInt(band) {
  switch (band) {
    case 'distinguished': return 35
    case 'high':          return 20
    case 'medium':        return 7
    default:              return 1
  }
}

// ── Venture helpers ──────────────────────────────────────────────────────────

// Find the open (active) venture for this actor, if any.
function findActiveVenture(pdb, actorId) {
  return pdb.prepare(`
    SELECT venture_id, venture_label FROM ventures
    WHERE actor_id = ? AND status = 'active'
    ORDER BY recorded_at DESC LIMIT 1
  `).get(actorId)
}

// Create a venture + venture_leg row on dispatch_start.
// Returns the new venture_id.
function createVenture(pdb, actorId, routeId, now) {
  const eco   = ROUTE_ECONOMICS[routeId]
  const cargo = ROUTE_CARGO[routeId]
  const h3    = ROUTE_H3[routeId]
  const mode  = ROUTE_MODE[routeId] || 'road'

  if (!eco || !cargo || !h3) return null  // unknown route — skip silently

  const ventureId = uuid()
  const legId     = uuid()

  const costVectura  = Math.round(eco.cost * COST_VECTURA_RATIO  * 100) / 100
  const costPortoria = Math.round(eco.cost * COST_PORTORIA_RATIO * 100) / 100
  const costOther    = Math.round((eco.cost - costVectura - costPortoria) * 100) / 100
  const durationDays = Math.round(eco.duration_ms / MS_PER_SIM_DAY)  // INTEGER

  const label = `${routeId.charAt(0).toUpperCase() + routeId.slice(1)} route`

  pdb.prepare(`
    INSERT INTO ventures
      (venture_id, actor_id, venture_label, status,
       cargo_type, cargo_unit, cost_total,
       recorded_at, started_at)
    VALUES (?, ?, ?, 'active', ?, ?, ?, ?, ?)
  `).run(ventureId, actorId, label, cargo.type, cargo.unit,
         eco.cost, now, now)

  pdb.prepare(`
    INSERT INTO venture_legs
      (leg_id, venture_id, leg_sequence,
       origin_h3, destination_h3, mode,
       duration_days, cost_vectura, cost_portoria, cost_other, cost_total,
       status, recorded_at, started_at)
    VALUES (?, ?, 1, ?, ?, ?, ?, ?, ?, ?, ?, 'active', ?, ?)
  `).run(legId, ventureId, h3.origin, h3.destination, mode,
         durationDays, costVectura, costPortoria, costOther, eco.cost,
         now, now)

  return ventureId
}

// Close the active venture on dispatch_complete.
// Writes outcome_net, completed_at, and closes the leg.
function closeVenture(pdb, actorId, routeId, ventureId, now) {
  const eco = ROUTE_ECONOMICS[routeId]
  if (!eco) return

  const outcomeNet = eco.profit - eco.cost

  pdb.prepare(`
    UPDATE ventures
    SET status = 'complete', revenue_total = ?, outcome_net = ?, completed_at = ?
    WHERE venture_id = ?
  `).run(eco.profit, outcomeNet, now, ventureId)

  pdb.prepare(`
    UPDATE venture_legs
    SET status = 'complete', completed_at = ?
    WHERE venture_id = ? AND status = 'active'
  `).run(now, ventureId)
}

// ── Drift log helpers ────────────────────────────────────────────────────────

function writeDriftLog(pdb, actorId, paramToken, triggerType, triggerRef,
                       valueBefore, valueAfter, deltaNote, now) {
  pdb.prepare(`
    INSERT INTO parameter_drift_log
      (actor_id, parameter_token, trigger_type, trigger_ref,
       value_before, value_after, delta_note, recorded_at)
    VALUES (?, ?, ?, ?, ?, ?, ?, ?)
  `).run(actorId, paramToken, triggerType, triggerRef,
         String(valueBefore), String(valueAfter), deltaNote, now)
}

// ── Write player state ───────────────────────────────────────────────────────

function writePlayerState(token, pdb, body) {
  const now = new Date().toISOString()
  const actorId = token

  // Ensure actor_profile exists
  const profile = pdb.prepare(
    'SELECT actor_id FROM actor_profile WHERE actor_id = ? LIMIT 1'
  ).get(actorId)

  if (!profile) {
    const backgroundId = body.background_id || 'unknown'
    const actorName    = body.actor_name    || 'Mercator'

    pdb.prepare(`
      INSERT OR IGNORE INTO actor_profile
        (actor_id, session_id, background_id, actor_name, epoch, schema_version, recorded_at)
      VALUES (?, ?, ?, ?, 'roman_14bce', 5, ?)
    `).run(actorId, actorId, backgroundId, actorName, now)

    pdb.prepare(`
      INSERT OR IGNORE INTO actor_parameters
        (actor_id, parameter_token, scope, layer,
         value_true, value_perceived, value_social,
         confidence_tag, observable_level, drift_source, recorded_at)
      SELECT
        ?, parameter_token, 'actor',
        CASE WHEN parameter_token IN ('auctoritas','clientela','liquiditas','fama',
             'disciplina','mercatus_scientia','itineris_scientia','ius_accessus',
             'periculum_tolerantia','negotiatio','litterae','officia_burden')
             THEN 'roman' ELSE 'universal' END,
        value_true, value_perceived,
        CASE WHEN parameter_token = 'auctoritas' THEN value_true ELSE NULL END,
        confidence_tag, observable_level, 'initial', ?
      FROM background_starting_values
      WHERE background_id = ?
    `).run(actorId, now, backgroundId)

    if (body.den !== undefined) {
      pdb.prepare(`
        UPDATE actor_parameters
        SET superseded_at = ?
        WHERE actor_id = ? AND parameter_token = 'liquiditas' AND superseded_at IS NULL
      `).run(now, actorId)
      pdb.prepare(`
        INSERT INTO actor_parameters
          (actor_id, parameter_token, scope, layer,
           value_true, value_perceived,
           confidence_tag, observable_level, drift_source, recorded_at)
        VALUES (?, 'liquiditas', 'actor', 'roman',
                ?, ?, 'measured', 'full', 'initial', ?)
      `).run(actorId, String(body.den), String(body.den), now)
    }
  }

  // Read current den/aut before any update — needed for drift log
  const currentLiq = pdb.prepare(`
    SELECT value_true FROM actor_parameters
    WHERE actor_id = ? AND parameter_token = 'liquiditas' AND superseded_at IS NULL
    ORDER BY recorded_at DESC LIMIT 1
  `).get(actorId)
  const currentAut = pdb.prepare(`
    SELECT value_true FROM actor_parameters
    WHERE actor_id = ? AND parameter_token = 'auctoritas' AND superseded_at IS NULL
    ORDER BY recorded_at DESC LIMIT 1
  `).get(actorId)

  const prevDen = currentLiq?.value_true ?? '0'
  const prevAut = currentAut?.value_true ?? 'low'

  // ── Process new events (Change 1 + Change 2) ─────────────────────────────

  const lastRecorded = pdb.prepare(`
    SELECT recorded_at FROM events
    WHERE actor_id = ?
    ORDER BY recorded_at DESC LIMIT 1
  `).get(actorId)
  const lastTs = lastRecorded?.recorded_at || '1970-01-01T00:00:00.000Z'

  const insertEvent = pdb.prepare(`
    INSERT INTO events (actor_id, event_type, ref_id, ref_type, payload, recorded_at)
    VALUES (?, ?, ?, ?, ?, ?)
  `)

  for (const ev of (body.events || [])) {
    const ts = ev.timestamp_utc || now
    if (ts <= lastTs) continue

    const routeId = ev.route_id || null

    // Change 1 — venture creation on dispatch_start
    if (ev.type === 'dispatch_start' && routeId) {
      const ventureId = createVenture(pdb, actorId, routeId, ts)
      insertEvent.run(
        actorId, ev.type, routeId, 'venture',
        JSON.stringify({ ...ev, venture_id: ventureId }),
        ts
      )
      continue
    }

    // Change 1 — venture closure on dispatch_complete
    if (ev.type === 'dispatch_complete' && routeId) {
      const active = findActiveVenture(pdb, actorId)
      if (active) {
        closeVenture(pdb, actorId, routeId, active.venture_id, ts)
        insertEvent.run(
          actorId, ev.type, routeId, 'venture',
          JSON.stringify({ ...ev, venture_id: active.venture_id }),
          ts
        )
      } else {
        insertEvent.run(
          actorId, ev.type, routeId, 'venture',
          JSON.stringify(ev), ts
        )
      }
      continue
    }

    // All other events — write as-is
    insertEvent.run(
      actorId,
      ev.type || 'unknown',
      routeId,
      routeId ? 'venture' : null,
      JSON.stringify(ev),
      ts
    )
  }

  // ── Update parameters + drift log (Change 2) ─────────────────────────────

  if (body.den !== undefined) {
    const newDen = String(body.den)
    if (newDen !== prevDen) {
      // Find the venture that just completed, if any — use as trigger_ref
      const lastVenture = pdb.prepare(`
        SELECT venture_id, venture_label FROM ventures
        WHERE actor_id = ? AND status = 'complete'
        ORDER BY completed_at DESC LIMIT 1
      `).get(actorId)

      updateParam(pdb, actorId, 'liquiditas', newDen, newDen, now)

      writeDriftLog(
        pdb, actorId, 'liquiditas',
        'venture_complete',
        lastVenture?.venture_id || null,
        prevDen, newDen,
        lastVenture?.venture_label || null,
        now
      )
    }
  }

  if (body.aut !== undefined) {
    const newBand = autBand(body.aut)
    if (newBand !== prevAut) {
      updateParamWithSocial(pdb, actorId, 'auctoritas', newBand, newBand, newBand, now)

      writeDriftLog(
        pdb, actorId, 'auctoritas',
        'interval_complete',
        null,
        prevAut, newBand,
        'otium rest',
        now
      )
    }
  }
}

function updateParam(pdb, actorId, token, valueTrue, valuePerceived, now) {
  pdb.prepare(`
    UPDATE actor_parameters
    SET superseded_at = ?
    WHERE actor_id = ? AND parameter_token = ? AND superseded_at IS NULL
  `).run(now, actorId, token)

  pdb.prepare(`
    INSERT INTO actor_parameters
      (actor_id, parameter_token, scope, layer,
       value_true, value_perceived,
       confidence_tag, observable_level, drift_source, recorded_at)
    VALUES (?, ?, 'actor', 'roman', ?, ?, 'measured', 'full', 'game_state', ?)
  `).run(actorId, token, valueTrue, valuePerceived, now)
}

function updateParamWithSocial(pdb, actorId, token, valueTrue, valuePerceived, valueSocial, now) {
  pdb.prepare(`
    UPDATE actor_parameters
    SET superseded_at = ?
    WHERE actor_id = ? AND parameter_token = ? AND superseded_at IS NULL
  `).run(now, actorId, token)

  pdb.prepare(`
    INSERT INTO actor_parameters
      (actor_id, parameter_token, scope, layer,
       value_true, value_perceived, value_social,
       confidence_tag, observable_level, drift_source, recorded_at)
    VALUES (?, ?, 'actor', 'roman', ?, ?, ?, 'indicated', 'partial', 'game_state', ?)
  `).run(actorId, token, valueTrue, valuePerceived, valueSocial, now)
}

// ── Fastify server ───────────────────────────────────────────────────────────

const fastify = Fastify({ logger: false })

await fastify.register(fastifyStatic, {
  root:   DIST,
  prefix: '/',
})

fastify.get('/api/map/:h5/:epoch', async (req, reply) => {
  const { h5: h5param, epoch: epochKey } = req.params

  if (!/^[0-9a-f]{15}$/.test(h5param)) {
    return reply.code(400).send({ error: 'Invalid H5 ID' })
  }
  if (!/^[a-z0-9_]+$/.test(epochKey)) {
    return reply.code(400).send({ error: 'Invalid epoch key' })
  }

  const epoch = stmtEpoch.get(epochKey)
  if (!epoch) {
    return reply.code(404).send({ error: `Unknown epoch: ${epochKey}` })
  }

  let h5int
  try {
    h5int = h3HexToInt(h5param)
  } catch {
    return reply.code(400).send({ error: 'Malformed H5 ID' })
  }

  const rows = stmtH7.all(epoch.sl_offset_cm, h5int)

  if (!rows.length) {
    return reply.code(404).send({ error: `No data for H5: ${h5param}` })
  }

  const cells = rows.map(row => ({
    h7:       row.h7.toString(16),
    lat:      row.lat,
    lon:      row.lon,
    h7_land:  row.h7_land,
    h9_total: row.h9_total,
    is_land:  row.h7_land * 2 > row.h9_total ? 1 : 0,
  }))

  return reply.send({
    epoch_key:    epochKey,
    sl_offset_cm: epoch.sl_offset_cm,
    h5:           h5param,
    cells,
  })
})

fastify.get('/api/save/:token', async (req, reply) => {
  const { token } = req.params
  if (!/^[0-9a-f]{8}$/.test(token)) {
    return reply.code(400).send({ error: 'Invalid token' })
  }

  const sqlitePath = join(SAVES_DIR, `${token}.sqlite3`)
  const jsonPath   = join(SAVES_DIR, `${token}.json`)

  if (existsSync(sqlitePath)) {
    try {
      const pdb   = openPlayerDb(token)
      const state = readPlayerState(token, pdb)
      pdb.close()
      return reply.send(state)
    } catch (err) {
      console.error(`[save GET] SQLite read failed for ${token}:`, err.message)
      return reply.code(500).send({ error: 'Failed to read player database' })
    }
  }

  if (existsSync(jsonPath)) {
    try {
      const raw  = await readFile(jsonPath, 'utf8')
      const json = JSON.parse(raw)
      const pdb  = openPlayerDb(token)
      migrateJsonToSqlite(token, pdb, json)
      const state = readPlayerState(token, pdb)
      pdb.close()
      console.log(`[save GET] Migrated ${token}.json → ${token}.sqlite3`)
      return reply.send(state)
    } catch (err) {
      console.error(`[save GET] Migration failed for ${token}:`, err.message)
      return reply.code(500).send({ error: 'Failed to migrate save' })
    }
  }

  return reply.code(404).send({ error: 'Save not found' })
})

fastify.post('/api/save/:token', async (req, reply) => {
  const { token } = req.params
  if (!/^[0-9a-f]{8}$/.test(token)) {
    return reply.code(400).send({ error: 'Invalid token' })
  }
  if (!req.body || typeof req.body !== 'object') {
    return reply.code(400).send({ error: 'Invalid body' })
  }

  try {
    const pdb = openPlayerDb(token)
    writePlayerState(token, pdb, req.body)
    pdb.close()
    return reply.send({ ok: true })
  } catch (err) {
    console.error(`[save POST] SQLite write failed for ${token}:`, err.message)
    return reply.code(500).send({ error: 'Failed to write player database' })
  }
})

fastify.setNotFoundHandler((req, reply) => {
  reply.sendFile('index.html')
})

try {
  await fastify.listen({ port: 3000, host: '0.0.0.0' })
  console.log('OTIVM server running on port 3000 — OTIVM-IV (Changes 1+2)')
} catch (err) {
  console.error(err)
  process.exit(1)
}