const os = require('os');
const fs = require('fs');
const path = require('path');
const { openRuntimeDb } = require('../src/db/runtime');
const { initAutonomySchema } = require('../src/autonomy/schema');
const { enqueueJob, leaseNextJob, completeJob, failJob } = require('../src/autonomy/jobs');
const { callCoordinator } = require('../src/autonomy/llm');
const { acceptProposal, recordRejectedProposal, INSTRUMENT_RULES } = require('../src/autonomy/coordinator');
const { EVENT_FAMILY_NAMES } = require('../src/autonomy/calibration');

function sleep(ms) { return new Promise((resolve) => setTimeout(resolve, ms)); }

function loadConfig() {
  const configPath = path.resolve(process.env.DURIIN_CONFIG || path.join(__dirname, '..', 'config.json'));
  const raw = JSON.parse(fs.readFileSync(configPath, 'utf8'));
  require('dotenv').config({ path: path.resolve(path.dirname(configPath), '.env') });
  raw.openRouter = { ...(raw.openRouter || {}) };
  if (process.env.OPEN_ROUTER_API_KEY) raw.openRouter.apiKey = process.env.OPEN_ROUTER_API_KEY;
  if (process.env.OPEN_ROUTER_LLM_MODEL) raw.openRouter.llmModel = process.env.OPEN_ROUTER_LLM_MODEL;
  return raw;
}

function articleTimeColumns(archiveDb) {
  const columns = new Set(archiveDb.prepare('PRAGMA table_info(articles)').all().map((row) => row.name));
  const candidates = ['pub_date_effective', 'pub_date', 'ingested_at'].filter((name) => columns.has(name));
  if (!candidates.length) throw new Error('archive articles need publication or ingestion timestamps for replay');
  return { columns, effective: candidates.length === 1 ? candidates[0] : `COALESCE(${candidates.join(', ')})` };
}

// bumped when the prompt changes in a way that changes what a prediction means.
const STRATEGY_VERSION = 'autonomy-2';
const PROMPT_VERSION = 'replay-coordinator-2';

function replayPrompt(article, feedbackBrief = '') {
  return `Historical evidence cutoff: ${article.effective_at}\n\n` +
    (feedbackBrief ? `${feedbackBrief}\n\n` : '') +
    `[Evidence 1] article_id=${article.id}\nTitle: ${article.title || ''}\n${String(article.content || article.description || '').slice(0, 6000)}\n\n` +
    `Return JSON only in this shape:\n${JSON.stringify({ predictions: [{
      instrument: '<ticker supported by the evidence>', direction: '<positive or negative>',
      event_type: '<one value from the event_type list below>',
      causal_channel: '<short description>', horizon_days: '<one of 1, 5, 10, 20, 30, 60, 90>',
      evidence_article_ids: ['<article_id values from the evidence above>'],
      invalidation_condition: '<what would falsify this>',
    }] }, null, 2)}\n\n` +
    'Every value in that shape is a placeholder describing the field. Do not copy them. Choose instrument, direction and horizon_days from the evidence in front of you.\n\n' +
    `event_type must be exactly one of: ${EVENT_FAMILY_NAMES.join(', ')}. Pick the closest one. Use "other" only when none of them genuinely apply, and never invent a value outside this list.\n\n` +
    `${INSTRUMENT_RULES}\n\n` +
    'Use only this dated evidence. Return an empty predictions array when there is no clear, tradable hypothesis. Never include probabilities, returns, confidence, position sizes, or actions.';
}

function activeRun(db, config) {
  let run = db.prepare("SELECT * FROM autonomy_replay_runs WHERE status = 'running' ORDER BY id DESC LIMIT 1").get();
  if (run) return run;

  // A fresh run used to recompute its watermark from today, so the run after a
  // pause covered a different archive slice and could never be compared with
  // the one before it. Inherit instead, and only fall back to the env window
  // when there is genuinely no predecessor.
  const previous = db.prepare('SELECT * FROM autonomy_replay_runs ORDER BY id DESC LIMIT 1').get();
  const watermarkDays = Math.max(1, Number(process.env.AUTONOMY_REPLAY_WATERMARK_DAYS) || 7);
  const watermark = previous && previous.watermark_at ? previous.watermark_at : null;
  const result = watermark
    ? db.prepare(`INSERT INTO autonomy_replay_runs (watermark_at, strategy_version, prompt_version, coordinator_model, parent_run_id)
        VALUES (?, ?, ?, ?, ?)`).run(watermark, STRATEGY_VERSION, PROMPT_VERSION, config.openRouter.llmModel || 'unknown', previous.id)
    : db.prepare(`INSERT INTO autonomy_replay_runs (watermark_at, strategy_version, prompt_version, coordinator_model)
        VALUES (datetime('now', ?), ?, ?, ?)`).run(`-${watermarkDays} days`, STRATEGY_VERSION, PROMPT_VERSION, config.openRouter.llmModel || 'unknown');
  return db.prepare('SELECT * FROM autonomy_replay_runs WHERE id = ?').get(result.lastInsertRowid);
}

// A run that has been handed an explicit article set walks only that set. This
// is what makes two runs comparable, they answer the same articles instead of
// two different windows of the archive.
function pinnedArticles(db, run, cursorEffectiveAt, cursorArticleId, limit) {
  const cursorFilter = cursorEffectiveAt
    ? 'AND (effective_at > ? OR (effective_at = ? AND article_id > ?))'
    : '';
  const params = [run.id];
  if (cursorEffectiveAt) params.push(cursorEffectiveAt, cursorEffectiveAt, cursorArticleId);
  return db.prepare(`
    SELECT article_id, effective_at FROM autonomy_replay_run_articles
    WHERE run_id = ? ${cursorFilter}
    ORDER BY effective_at ASC, article_id ASC LIMIT ${limit}
  `).all(...params);
}

function hasPinnedSet(db, run) {
  return !!db.prepare('SELECT 1 FROM autonomy_replay_run_articles WHERE run_id = ? LIMIT 1').get(run.id);
}

function scheduleNext(db, archiveDb, run) {
  if (hasPinnedSet(db, run)) return schedulePinned(db, archiveDb, run);
  const { columns, effective } = articleTimeColumns(archiveDb);
  const content = columns.has('content') ? "content IS NOT NULL AND content != ''" : '1=1';
  const indexFilter = columns.has('is_index_page') ? 'AND (is_index_page = 0 OR is_index_page IS NULL)' : '';
  let cursorEffectiveAt = run.cursor_effective_at;
  let cursorArticleId = run.cursor_article_id;

  for (let skipped = 0; skipped < 100; skipped += 1) {
    const cursorFilter = cursorEffectiveAt
      ? `AND (datetime(${effective}) > datetime(?) OR (datetime(${effective}) = datetime(?) AND id > ?))`
      : '';
    const params = [run.watermark_at];
    if (cursorEffectiveAt) params.push(cursorEffectiveAt, cursorEffectiveAt, cursorArticleId);
    const article = archiveDb.prepare(`
      SELECT id, title, description, content, ${effective} AS effective_at
      FROM articles
      WHERE ${content} ${indexFilter} AND datetime(${effective}) <= datetime(?) ${cursorFilter}
      ORDER BY datetime(${effective}) ASC, id ASC LIMIT 1
    `).get(...params);
    if (!article) return null;

    const idempotencyKey = `replay:${run.id}:article:${article.id}`;
    const existing = db.prepare('SELECT status, last_error FROM autonomy_jobs WHERE idempotency_key = ?').get(idempotencyKey);
    if (existing && ['complete', 'dead_letter'].includes(existing.status)) {
      db.prepare(`
        UPDATE autonomy_replay_runs
        SET cursor_article_id=?, cursor_effective_at=?, last_error=?, updated_at=datetime('now')
        WHERE id=?
      `).run(article.id, article.effective_at, existing.status === 'dead_letter'
        ? `Skipped dead-letter replay job for article ${article.id}: ${existing.last_error || 'unknown error'}`
        : run.last_error, run.id);
      cursorEffectiveAt = article.effective_at;
      cursorArticleId = article.id;
      continue;
    }

    enqueueJob(db, {
      jobType: 'replay_article', lane: 'historical', priority: 1, entityType: 'article', entityId: article.id,
      idempotencyKey,
    });
    return article;
  }
  throw new Error('replay scheduler skipped too many terminal jobs in one pass');
}

function schedulePinned(db, archiveDb, run) {
  const { effective } = articleTimeColumns(archiveDb);
  let cursorEffectiveAt = run.cursor_effective_at;
  let cursorArticleId = run.cursor_article_id;

  for (let skipped = 0; skipped < 100; skipped += 1) {
    const [next] = pinnedArticles(db, run, cursorEffectiveAt, cursorArticleId, 1);
    if (!next) return null;
    const article = archiveDb.prepare(
      `SELECT id, title, description, content, ${effective} AS effective_at FROM articles WHERE id = ?`
    ).get(next.article_id);

    const idempotencyKey = `replay:${run.id}:article:${next.article_id}`;
    const existing = db.prepare('SELECT status, last_error FROM autonomy_jobs WHERE idempotency_key = ?').get(idempotencyKey);
    const terminal = existing && ['complete', 'dead_letter'].includes(existing.status);
    if (!article || terminal) {
      db.prepare(`UPDATE autonomy_replay_runs SET cursor_article_id=?, cursor_effective_at=?, last_error=?, updated_at=datetime('now') WHERE id=?`)
        .run(next.article_id, next.effective_at, !article
          ? `Pinned article ${next.article_id} is no longer in the archive`
          : (existing.status === 'dead_letter'
            ? `Skipped dead-letter replay job for article ${next.article_id}: ${existing.last_error || 'unknown error'}`
            : run.last_error), run.id);
      if (!article) console.error(`[replay] run ${run.id} pinned article ${next.article_id} is missing from the archive, skipping`);
      cursorEffectiveAt = next.effective_at;
      cursorArticleId = next.article_id;
      continue;
    }

    enqueueJob(db, {
      jobType: 'replay_article', lane: 'historical', priority: 1, entityType: 'article', entityId: next.article_id,
      idempotencyKey,
    });
    return article;
  }
  throw new Error('pinned replay scheduler skipped too many terminal jobs in one pass');
}

// leaseNextJob hands back any pending replay_article job, it knows nothing
// about runs. Attributing whatever comes back to the currently active run means
// one recovered dead letter from an older run gets that run's article stamped
// with the new run's id, the new run's brief in its prompt, and worst of all
// drags the new run's cursor to wherever that old article sat in the archive.
// A pinned run would then find its set "finished" after a couple of articles.
// The job says which run it belongs to, so ask the job.
function runForJob(db, job, fallback) {
  const match = /^replay:(\d+):article:/.exec(String(job.idempotency_key || ''));
  if (!match) {
    console.error(`[replay] job ${job.id} has no run in its idempotency key`
      + ` (${job.idempotency_key}), attributing it to run ${fallback.id}`);
    return fallback;
  }
  const run = db.prepare('SELECT * FROM autonomy_replay_runs WHERE id = ?').get(Number(match[1]));
  if (!run) {
    console.error(`[replay] job ${job.id} points at run ${match[1]} which no longer exists,`
      + ` attributing it to run ${fallback.id}`);
    return fallback;
  }
  return run;
}

async function runReplayWorker({ archivePath, intelligencePath, workerId = `replay-${os.hostname()}-${process.pid}`, pollMs = 15000 } = {}) {
  const archiveDb = openRuntimeDb(archivePath, { schema: 'archive', readonly: true });
  const db = openRuntimeDb(intelligencePath, { schema: 'intelligence' });
  db.pragma('journal_mode = WAL');
  db.pragma('busy_timeout = 5000');
  initAutonomySchema(db);
  const config = loadConfig();
  const dailyBudget = Math.max(1, Number(process.env.AUTONOMY_REPLAY_DAILY_BUDGET) || 100);
  while (true) {
    try {
      const completedToday = db.prepare("SELECT COUNT(*) AS count FROM autonomy_jobs WHERE job_type='replay_article' AND status='complete' AND date(completed_at) = date('now')").get().count;
      if (completedToday >= dailyBudget) { await sleep(Math.max(pollMs, 60000)); continue; }
      const run = activeRun(db, config);
      scheduleNext(db, archiveDb, run);
      const job = leaseNextJob(db, workerId, 300, ['replay_article']);
      if (!job) { await sleep(pollMs); continue; }
      const owner = runForJob(db, job, run);
      try {
        const { effective } = articleTimeColumns(archiveDb);
        const article = archiveDb.prepare(`SELECT id, title, description, content, ${effective} AS effective_at FROM articles WHERE id=?`).get(job.entity_id);
        if (!article || !article.effective_at) throw new Error(`replay article ${job.entity_id} is unavailable`);
        const raw = await callCoordinator(config, replayPrompt(article, owner.feedback_brief || ''));
        try {
          acceptProposal(db, archiveDb, raw, {
            informationCutoff: article.effective_at, model: config.openRouter.llmModel || 'unknown',
            promptVersion: owner.prompt_version || PROMPT_VERSION,
            strategyVersion: owner.strategy_version || STRATEGY_VERSION, learningEligible: false,
            origin: 'replay', replayRunId: owner.id,
          });
        } catch (validationError) {
          console.error(`[${workerId}] replay proposal rejected for article ${article.id}:`, validationError.message);
          recordRejectedProposal(db, raw, { informationCutoff: article.effective_at, model: config.openRouter.llmModel || 'unknown', promptVersion: owner.prompt_version || PROMPT_VERSION, origin: 'replay' }, validationError.message);
        }
        db.prepare(`UPDATE autonomy_replay_runs SET cursor_article_id=?, cursor_effective_at=?, processed_articles=processed_articles+1, updated_at=datetime('now') WHERE id=?`)
          .run(article.id, article.effective_at, owner.id);
        completeJob(db, job.id, workerId);
      } catch (error) { failJob(db, job.id, workerId, error); }
    } catch (error) { console.error(`[${workerId}] replay error:`, error.message); }
    await sleep(pollMs);
  }
}

module.exports = { articleTimeColumns, replayPrompt, scheduleNext, schedulePinned, runForJob,
  runReplayWorker, STRATEGY_VERSION, PROMPT_VERSION };