const Database = require('better-sqlite3');
const path = require('path');
const fs = require('fs');

const dbPath = path.join(__dirname, '../../data');
const db = new Database(path.join(dbPath, 'breedr.db'));

function getDatabase() {
  return db;
}

function initDatabase() {
  db.pragma('foreign_keys = ON');
  db.pragma('journal_mode = WAL');

  // ── Dogs ────────────────────────────────────────────────────────────────
  db.exec(`
    CREATE TABLE IF NOT EXISTS dogs (
      id                          INTEGER PRIMARY KEY AUTOINCREMENT,
      name                        TEXT NOT NULL,
      registration_number         TEXT,
      breed                       TEXT NOT NULL,
      sex                         TEXT NOT NULL CHECK(sex IN ('male', 'female')),
      birth_date                  TEXT,
      color                       TEXT,
      microchip                   TEXT,
      litter_id                   INTEGER,
      is_active                   INTEGER DEFAULT 1,
      is_champion                 INTEGER DEFAULT 0,
      is_external                 INTEGER DEFAULT 0,
      chic_number                 TEXT,
      age_at_death                TEXT,
      cause_of_death              TEXT,
      photo_urls                  TEXT DEFAULT '[]',
      notes                       TEXT,
      created_at                  TEXT DEFAULT (datetime('now')),
      updated_at                  TEXT DEFAULT (datetime('now'))
    )
  `);

  // migrate: add columns if missing (safe on existing DBs)
  const dogMigrations = [
    ['is_champion',    'INTEGER DEFAULT 0'],
    ['is_external',    'INTEGER DEFAULT 0'],
    ['chic_number',    'TEXT'],
    ['age_at_death',   'TEXT'],
    ['cause_of_death', 'TEXT'],
  ];
  for (const [col, def] of dogMigrations) {
    try { db.exec(`ALTER TABLE dogs ADD COLUMN ${col} ${def}`); } catch (_) { /* already exists */ }
  }

  // ── Parents ──────────────────────────────────────────────────────────────
  db.exec(`
    CREATE TABLE IF NOT EXISTS parents (
      id          INTEGER PRIMARY KEY AUTOINCREMENT,
      dog_id      INTEGER NOT NULL,
      parent_id   INTEGER NOT NULL,
      parent_type TEXT NOT NULL CHECK(parent_type IN ('sire', 'dam')),
      FOREIGN KEY (dog_id)    REFERENCES dogs(id),
      FOREIGN KEY (parent_id) REFERENCES dogs(id)
    )
  `);

  // ── Breeding Records ─────────────────────────────────────────────────────
  db.exec(`
    CREATE TABLE IF NOT EXISTS breeding_records (
      id                  INTEGER PRIMARY KEY AUTOINCREMENT,
      sire_id             INTEGER NOT NULL,
      dam_id              INTEGER NOT NULL,
      breeding_date       TEXT,
      due_date            TEXT,
      conception_method   TEXT CHECK(conception_method IN ('natural', 'ai', 'frozen', 'surgical')),
      notes               TEXT,
      created_at          TEXT DEFAULT (datetime('now')),
      updated_at          TEXT DEFAULT (datetime('now')),
      FOREIGN KEY (sire_id) REFERENCES dogs(id),
      FOREIGN KEY (dam_id)  REFERENCES dogs(id)
    )
  `);

  // ── Litters ──────────────────────────────────────────────────────────────
  db.exec(`
    CREATE TABLE IF NOT EXISTS litters (
      id              INTEGER PRIMARY KEY AUTOINCREMENT,
      breeding_id     INTEGER,
      sire_id         INTEGER NOT NULL,
      dam_id          INTEGER NOT NULL,
      whelp_date      TEXT,
      total_count     INTEGER DEFAULT 0,
      male_count      INTEGER DEFAULT 0,
      female_count    INTEGER DEFAULT 0,
      stillborn_count INTEGER DEFAULT 0,
      notes           TEXT,
      created_at      TEXT DEFAULT (datetime('now')),
      updated_at      TEXT DEFAULT (datetime('now')),
      FOREIGN KEY (breeding_id) REFERENCES breeding_records(id),
      FOREIGN KEY (sire_id)     REFERENCES dogs(id),
      FOREIGN KEY (dam_id)      REFERENCES dogs(id)
    )
  `);

  // ── Health Records (OFA-extended) ─────────────────────────────────────────
  db.exec(`
    CREATE TABLE IF NOT EXISTS health_records (
      id             INTEGER PRIMARY KEY AUTOINCREMENT,
      dog_id         INTEGER NOT NULL,
      record_type    TEXT NOT NULL,
      test_type      TEXT,
      test_name      TEXT,
      test_date      TEXT NOT NULL,
      ofa_result     TEXT,
      ofa_number     TEXT,
      performed_by   TEXT,
      expires_at     TEXT,
      document_url   TEXT,
      result         TEXT,
      vet_name       TEXT,
      next_due       TEXT,
      notes          TEXT,
      created_at     TEXT DEFAULT (datetime('now')),
      updated_at     TEXT DEFAULT (datetime('now')),
      FOREIGN KEY (dog_id) REFERENCES dogs(id)
    )
  `);

  // migrate: add OFA-specific columns if missing (covers existing DBs)
  const healthMigrations = [
    ['test_type',     'TEXT'],
    ['ofa_result',   'TEXT'],
    ['ofa_number',   'TEXT'],
    ['performed_by', 'TEXT'],
    ['expires_at',   'TEXT'],
    ['document_url', 'TEXT'],
    ['result',       'TEXT'],
    ['vet_name',     'TEXT'],
    ['next_due',     'TEXT'],
  ];
  for (const [col, def] of healthMigrations) {
    try { db.exec(`ALTER TABLE health_records ADD COLUMN ${col} ${def}`); } catch (_) { /* already exists */ }
  }

  // ── Genetic Tests (DNA Panel) ──────────────────────────────────────────────
  db.exec(`
    CREATE TABLE IF NOT EXISTS genetic_tests (
      id              INTEGER PRIMARY KEY AUTOINCREMENT,
      dog_id          INTEGER NOT NULL,
      test_provider   TEXT,
      marker          TEXT NOT NULL,
      result          TEXT NOT NULL CHECK(result IN ('clear', 'carrier', 'affected', 'not_tested')),
      test_date       TEXT,
      document_url    TEXT,
      notes           TEXT,
      created_at      TEXT DEFAULT (datetime('now')),
      updated_at      TEXT DEFAULT (datetime('now')),
      FOREIGN KEY (dog_id) REFERENCES dogs(id)
    )
  `);

  const geneticMigrations = [
    ['test_provider', 'TEXT'],
    ['marker', "TEXT NOT NULL DEFAULT 'unknown'"],
    ['result', "TEXT NOT NULL DEFAULT 'not_tested'"],
    ['test_date', 'TEXT'],
    ['document_url', 'TEXT'],
    ['notes', 'TEXT']
  ];
  for (const [col, def] of geneticMigrations) {
    try { db.exec(`ALTER TABLE genetic_tests ADD COLUMN ${col} ${def}`); } catch (_) {}
  }

  // ── Cancer History ────────────────────────────────────────────────────────
  db.exec(`
    CREATE TABLE IF NOT EXISTS cancer_history (
      id                  INTEGER PRIMARY KEY AUTOINCREMENT,
      dog_id              INTEGER NOT NULL,
      cancer_type         TEXT,
      age_at_diagnosis    TEXT,
      age_at_death        TEXT,
      cause_of_death      TEXT,
      notes               TEXT,
      created_at          TEXT DEFAULT (datetime('now')),
      updated_at          TEXT DEFAULT (datetime('now')),
      FOREIGN KEY (dog_id) REFERENCES dogs(id)
    )
  `);

  const cancerMigrations = [
    ['cancer_type', 'TEXT'],
    ['age_at_diagnosis', 'TEXT'],
    ['age_at_death', 'TEXT'],
    ['cause_of_death', 'TEXT'],
    ['notes', 'TEXT']
  ];
  for (const [col, def] of cancerMigrations) {
    try { db.exec(`ALTER TABLE cancer_history ADD COLUMN ${col} ${def}`); } catch (_) {}
  }

  // ── Settings ──────────────────────────────────────────────────────────────
  db.exec(`
    CREATE TABLE IF NOT EXISTS settings (
      id              INTEGER PRIMARY KEY AUTOINCREMENT,
      kennel_name     TEXT DEFAULT 'BREEDR',
      kennel_tagline  TEXT,
      kennel_address  TEXT,
      kennel_phone    TEXT,
      kennel_email    TEXT,
      kennel_website  TEXT,
      kennel_akc_id   TEXT,
      kennel_breed    TEXT,
      owner_name      TEXT,
      created_at      TEXT DEFAULT (datetime('now')),
      updated_at      TEXT DEFAULT (datetime('now'))
    )
  `);

  const kennelCols = [
    ['kennel_name',    "TEXT DEFAULT 'BREEDR'"],
    ['kennel_tagline', 'TEXT'],
    ['kennel_address', 'TEXT'],
    ['kennel_phone',   'TEXT'],
    ['kennel_email',   'TEXT'],
    ['kennel_website', 'TEXT'],
    ['kennel_akc_id',  'TEXT'],
    ['kennel_breed',   'TEXT'],
    ['owner_name',     'TEXT'],
  ];
  for (const [col, def] of kennelCols) {
    try { db.exec(`ALTER TABLE settings ADD COLUMN ${col} ${def}`); } catch (_) { /* already exists */ }
  }

  const existing = db.prepare('SELECT id FROM settings LIMIT 1').get();
  if (!existing) {
    db.prepare(`INSERT INTO settings (kennel_name) VALUES (?)`).run('BREEDR');
  }

  console.log('✓ Database initialized successfully');
}

module.exports = { getDatabase, initDatabase };