// MySQL data layer (Marty: real concurrency over flat files).
// DATABASE_URL present  -> mysql2 pool, schema bootstrap, one-time import of
//                          any existing volume JSON (accounts/sessions/
//                          campaigns) so nothing is lost on the switch.
// DATABASE_URL absent   -> db.enabled() is false and the modules fall back to
//                          their JSON stores (local dev keeps working).
// The chain index stays a file: it is a rebuildable cache of the blockchain.
const fs = require('fs');
const path = require('path');

let pool = null;
let DATA_DIR = null;

function enabled() { return !!process.env.DATABASE_URL; }

async function init(opts) {
  DATA_DIR = opts.dataDir;
  if (!enabled()) return false;
  const mysql = require('mysql2/promise');
  pool = mysql.createPool(process.env.DATABASE_URL + '?connectionLimit=10&charset=utf8mb4');
  await bootstrap();
  await importJsonOnce();
  console.log('db: MySQL connected, schema ready');
  return true;
}
const q = async (sql, params) => (await pool.query(sql, params))[0];

async function bootstrap() {
  await q(`CREATE TABLE IF NOT EXISTS accounts (
    email VARCHAR(190) PRIMARY KEY,
    pass VARCHAR(200) NULL,
    sponsor_ref VARCHAR(32) NOT NULL DEFAULT '',
    code VARCHAR(16) NOT NULL UNIQUE,
    address VARCHAR(64) NULL UNIQUE,
    created BIGINT NOT NULL,
    last_seen BIGINT NULL
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4`);
  await q(`CREATE TABLE IF NOT EXISTS sessions (
    token VARCHAR(80) PRIMARY KEY,
    email VARCHAR(190) NULL,
    address VARCHAR(64) NULL,
    member_id INT NOT NULL DEFAULT 0,
    expires BIGINT NOT NULL,
    INDEX (expires)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4`);
  await q(`CREATE TABLE IF NOT EXISTS campaigns (
    id INT AUTO_INCREMENT PRIMARY KEY,
    owner_email VARCHAR(190) NOT NULL,
    member_id INT NOT NULL,
    type VARCHAR(12) NOT NULL,
    name VARCHAR(80) NOT NULL,
    target_url VARCHAR(500) NOT NULL,
    image_url VARCHAR(500) NULL,
    title VARCHAR(80) NULL,
    body VARCHAR(200) NULL,
    budget INT NOT NULL,
    spent INT NOT NULL DEFAULT 0,
    accrued INT NOT NULL DEFAULT 0,
    imps INT NOT NULL DEFAULT 0,
    clicks INT NOT NULL DEFAULT 0,
    batch_imps INT NOT NULL DEFAULT 0,
    status VARCHAR(12) NOT NULL DEFAULT 'active',
    last_day_charged VARCHAR(10) NULL,
    created BIGINT NOT NULL,
    INDEX (owner_email), INDEX (type, status), INDEX (member_id)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4`);
  await q(`CREATE TABLE IF NOT EXISTS earned_credits (
    email VARCHAR(190) PRIMARY KEY,
    balance INT NOT NULL DEFAULT 0,
    granted_welcome TINYINT NOT NULL DEFAULT 0,
    updated BIGINT NOT NULL
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4`);
  const alterSafe0 = async sql => { try { await q(sql); } catch (e) { if (!['ER_DUP_FIELDNAME', 'ER_DUP_KEYNAME'].includes(e.code)) throw e; } };
  await alterSafe0('ALTER TABLE earned_credits ADD COLUMN milestones VARCHAR(255) NULL'); // comma-joined granted milestone keys
  // additive columns (MySQL 8 has no IF NOT EXISTS for columns)
  const alterSafe = async sql => {
    try { await q(sql); }
    catch (e) { if (!['ER_DUP_FIELDNAME', 'ER_DUP_KEYNAME'].includes(e.code)) throw e; }
  };
  await alterSafe('ALTER TABLE accounts ADD COLUMN username VARCHAR(30) NULL');
  await alterSafe('ALTER TABLE accounts ADD UNIQUE KEY uq_username (username)');
  await alterSafe('ALTER TABLE accounts ADD COLUMN member_id INT NULL');
  await alterSafe('ALTER TABLE accounts ADD KEY idx_member (member_id)');
  await alterSafe('ALTER TABLE accounts ADD COLUMN avatar_url VARCHAR(500) NULL');
  await alterSafe('ALTER TABLE accounts ADD COLUMN bio VARCHAR(600) NULL');
  await alterSafe('ALTER TABLE accounts ADD COLUMN line_banner_url VARCHAR(500) NULL');
  await alterSafe('ALTER TABLE accounts ADD COLUMN line_target_url VARCHAR(500) NULL');
  await q(`CREATE TABLE IF NOT EXISTS daily_views (
    email VARCHAR(190) NOT NULL,
    day CHAR(10) NOT NULL,
    views INT NOT NULL DEFAULT 0,
    claimed TINYINT NOT NULL DEFAULT 0,
    last_ts BIGINT NOT NULL DEFAULT 0,
    PRIMARY KEY (email, day)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4`);
  await alterSafe('ALTER TABLE daily_views ADD COLUMN video_count INT NOT NULL DEFAULT 0'); // watch-to-earn videos/day
  await q(`CREATE TABLE IF NOT EXISTS solo_inbox (
    id INT AUTO_INCREMENT PRIMARY KEY,
    campaign_id INT NOT NULL,
    email VARCHAR(190) NOT NULL,
    delivered BIGINT NOT NULL,
    read_ts BIGINT NULL,
    visited_ts BIGINT NULL,
    rewarded TINYINT NOT NULL DEFAULT 0,
    rewarded_day CHAR(10) NULL,
    UNIQUE KEY uq_solo (campaign_id, email),
    INDEX (email), INDEX (email, rewarded, rewarded_day)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4`);
  await alterSafe('ALTER TABLE solo_inbox ADD COLUMN visited_ts BIGINT NULL');
  // solo message bodies are sanitized rich text; TEXT gives them room
  await alterSafe('ALTER TABLE campaigns MODIFY body TEXT NULL');
  await alterSafe('ALTER TABLE campaigns ADD COLUMN cta_label VARCHAR(40) NULL');
  await alterSafe('ALTER TABLE campaigns ADD COLUMN width INT NULL');   // banner size (IAB) → also NAS width
  await alterSafe('ALTER TABLE campaigns ADD COLUMN height INT NULL');  // banner size (IAB) → also NAS height
  await alterSafe('ALTER TABLE campaigns ADD COLUMN nas_ad_id INT NULL');          // syndicated NAS sponsorads.ID
  await alterSafe('ALTER TABLE campaigns ADD COLUMN nas_served INT NOT NULL DEFAULT 0'); // NAS impressions already reconciled into spend
  await alterSafe('ALTER TABLE campaigns ADD COLUMN expires BIGINT NULL'); // featured rotation end time
  await q(`CREATE TABLE IF NOT EXISTS sponsor_messages (
    id INT AUTO_INCREMENT PRIMARY KEY,
    from_member INT NOT NULL,
    from_email VARCHAR(190) NOT NULL,
    to_email VARCHAR(190) NOT NULL,
    subject VARCHAR(160) NOT NULL,
    body TEXT NULL,
    sent BIGINT NOT NULL,
    read_ts BIGINT NULL,
    INDEX (to_email, read_ts), INDEX (from_email, sent)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4`);
  await q(`CREATE TABLE IF NOT EXISTS burns (
    id VARCHAR(32) PRIMARY KEY,
    member_id INT NOT NULL,
    amount INT NOT NULL,
    ref VARCHAR(64) NOT NULL,
    ts BIGINT NOT NULL,
    burned_tx VARCHAR(80) NULL,
    burned_at BIGINT NULL,
    INDEX (burned_tx)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4`);
}

// one-time import: only when the tables are empty and JSON files exist
async function importJsonOnce() {
  const [{ n }] = await q('SELECT COUNT(*) n FROM accounts');
  if (n > 0) return;
  try {
    const a = JSON.parse(fs.readFileSync(path.join(DATA_DIR, 'accounts.json'), 'utf8'));
    for (const acc of Object.values(a.byEmail || {})) {
      await q('INSERT IGNORE INTO accounts (email,pass,sponsor_ref,code,address,created) VALUES (?,?,?,?,?,?)',
        [acc.email, acc.pass || null, String(acc.sponsorRef || acc.sponsorId || ''), acc.code, acc.address || null, acc.created || Date.now()]);
    }
    console.log('db: imported', Object.keys(a.byEmail || {}).length, 'account(s) from JSON');
  } catch (e) {}
  try {
    const c = JSON.parse(fs.readFileSync(path.join(DATA_DIR, 'campaigns.json'), 'utf8'));
    for (const cp of c.campaigns || []) {
      await q(`INSERT IGNORE INTO campaigns (owner_email,member_id,type,name,target_url,image_url,title,body,
        budget,spent,accrued,imps,clicks,batch_imps,status,last_day_charged,created)
        VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)`,
        [cp.owner, cp.memberId, cp.type, cp.name, cp.targetUrl, cp.imageUrl || null, cp.title || null, cp.body || null,
         cp.budget, cp.spent || 0, cp.accrued || 0, cp.imps || 0, cp.clicks || 0, cp.batchImps || 0,
         cp.status, cp.lastDayCharged || null, cp.created || Date.now()]);
    }
    for (const b of c.burnsPending || []) {
      await q('INSERT IGNORE INTO burns (id,member_id,amount,ref,ts,burned_tx,burned_at) VALUES (?,?,?,?,?,?,?)',
        [b.id, b.memberId, b.amount, b.ref, b.ts, b.burnedTx || null, b.burnedAt || null]);
    }
    console.log('db: imported', (c.campaigns || []).length, 'campaign(s) from JSON');
  } catch (e) {}
  try {
    const s = JSON.parse(fs.readFileSync(path.join(DATA_DIR, 'sessions.json'), 'utf8'));
    for (const [tok, sess] of Object.entries(s)) {
      if (sess.expires > Date.now()) {
        await q('INSERT IGNORE INTO sessions (token,email,address,member_id,expires) VALUES (?,?,?,?,?)',
          [tok, sess.email || null, sess.address || null, sess.memberId || 0, sess.expires]);
      }
    }
  } catch (e) {}
}

module.exports = { init, enabled, q: (...a) => q(...a) };