// Centralized configuration store.
//
// Replaces the .env file: all settings live in the SQLite app_state table
// (rows prefixed "cfg:") and are editable via the /einstellungen page. The
// libs read values through config.get() / config.ollama() at *call* time, so
// an edit in the UI takes effect immediately — no restart, no .env file.
//
// On first start of an install that previously used .env, init() migrates any
// still-present env value into the DB once, so existing config is not lost.
// After that the database is the single source of truth; process.env is only a
// fallback for keys that were never saved (and for the one-time migration).

const DEFAULTS = {
  // Ollama Cloud (KI text generation + chat).
  OLLAMA_API_KEY: '',
  OLLAMA_MODEL: 'gpt-oss:120b',
  OLLAMA_HOST: 'https://ollama.com',
  OLLAMA_TIMEOUT_MS: '300000',
  // E-Mail (SMTP submission + IMAP receive).
  MAIL_HOST: '',
  MAIL_SMTP_PORT: '587',
  MAIL_IMAP_PORT: '993',
  MAIL_USER: '',
  MAIL_PASSWORD: '',
  MAIL_FROM_NAME: '',
  MAIL_FROM: '',
  MAIL_IMAP_MAILBOX: 'INBOX',
  MAIL_POLL_MS: '180000',
  // Bewerbungskalender (CalDAV, z. B. SOGo).
  CALDAV_URL: '',
  CALDAV_ALARM_MIN: '60',
  CALDAV_POLL_MS: '300000',
  // REST-API für Drittanbietersoftware (/api/v1, Header X-API-Key).
  API_TOKEN: '',
};

// UI metadata for the /einstellungen page: grouped sections with input types.
// `secret` fields render as password inputs with a reveal toggle.
const FIELDS = [
  {
    titel: 'Ollama Cloud (KI-Generierung + Chat)',
    beschreibung: 'Steuerung der KI, die Bewerbungsunterlagen erzeugt und den KI-Chat beantwortet. Ohne API-Schlüssel sind diese Funktionen deaktiviert.',
    items: [
      { key: 'OLLAMA_API_KEY', label: 'API-Schlüssel', secret: true, help: 'Schlüssel von https://ollama.com/settings/keys' },
      { key: 'OLLAMA_MODEL', label: 'Modell', help: 'Standard: gpt-oss:120b' },
      { key: 'OLLAMA_HOST', label: 'Host', help: 'Standard: https://ollama.com — lokaler Ollama: http://localhost:11434' },
      { key: 'OLLAMA_TIMEOUT_MS', label: 'Timeout (ms)', help: 'Standard: 300000 (5 Min.)' },
    ],
  },
  {
    titel: 'E-Mail (SMTP-Versand + IMAP-Empfang)',
    beschreibung: 'Versand läuft über den eigenen Mailserver (DKIM/SPF/DMARC-Alignment). Ohne Host/Benutzer/Passwort ist der E-Mail-Teil deaktiviert.',
    items: [
      { key: 'MAIL_HOST', label: 'SMTP/IMAP Host' },
      { key: 'MAIL_SMTP_PORT', label: 'SMTP-Port', help: '587 = STARTTLS, 465 = implicit TLS' },
      { key: 'MAIL_IMAP_PORT', label: 'IMAP-Port', help: 'Standard: 993 (implicit TLS)' },
      { key: 'MAIL_USER', label: 'Benutzername (Login)', help: 'Auch CalDAV-Login' },
      { key: 'MAIL_PASSWORD', label: 'Passwort', secret: true, help: 'Auch CalDAV-Passwort' },
      { key: 'MAIL_FROM_NAME', label: 'Absendername' },
      { key: 'MAIL_FROM', label: 'Absenderadresse', help: 'Leer = Benutzername' },
      { key: 'MAIL_IMAP_MAILBOX', label: 'IMAP-Postfach', help: 'Standard: INBOX' },
      { key: 'MAIL_POLL_MS', label: 'Abrufintervall (ms)', help: 'Standard: 180000 (3 Min.) — greift nach Neustart' },
    ],
  },
  {
    titel: 'Bewerbungskalender (CalDAV)',
    beschreibung: 'Voll-URL der Kalender-Sammlung (mit abschließendem /). Authentifizierung läuft über MAIL_USER/MAIL_PASSWORD. Ohne URL sind die Kalender-Funktionen deaktiviert.',
    items: [
      { key: 'CALDAV_URL', label: 'Kalender-URL', help: 'z. B. https://mail.example.com/SOGo/dav/name@…/Calendar/XXXX/' },
      { key: 'CALDAV_ALARM_MIN', label: 'Erinnerung (Minuten vor Termin)', help: 'Standard: 60' },
      { key: 'CALDAV_POLL_MS', label: 'Sync-Intervall (ms)', help: 'Standard: 300000 (5 Min.) — greift nach Neustart' },
    ],
  },
  {
    titel: 'REST-API für Drittanbietersoftware',
    beschreibung: 'Ist ein Token gesetzt, ist /api/v1 aktiv und erwartet den Wert im Header „X-API-Key“. Ohne Token antwortet die API (bis auf /health) mit 503. Swagger unter /swagger.',
    items: [
      { key: 'API_TOKEN', label: 'API-Token (X-API-Key)', secret: true, help: 'Leer = API deaktiviert' },
    ],
  },
];

const PREFIX = 'cfg:';
const cache = Object.create(null); // key -> string (only keys present in the DB)
let dbAllFn = null;
let dbRunFn = null;

function envOrDefault(key) {
  const e = process.env[key];
  return e && e.length ? e : DEFAULTS[key];
}

// Synchronous read. Falls back to process.env (pre-migration / never saved)
// then to the built-in default. After init() the DB value is cached and wins.
function get(key) {
  const v = cache[key];
  if (v !== undefined) return v;
  return envOrDefault(key);
}

// All keys with their effective values, keyed by name — used by the settings UI.
function getAll() {
  const out = {};
  for (const key of Object.keys(DEFAULTS)) out[key] = get(key);
  return out;
}

// Ollama bundle (shared by lib/documents.js + lib/chat.js).
function ollama() {
  return {
    host: (get('OLLAMA_HOST') || 'https://ollama.com').replace(/\/+$/, ''),
    model: get('OLLAMA_MODEL') || 'gpt-oss:120b',
    timeoutMs: Number(get('OLLAMA_TIMEOUT_MS')) || 300000,
    apiKey: get('OLLAMA_API_KEY') || '',
  };
}

async function load() {
  if (!dbAllFn) return;
  const rows = await dbAllFn('SELECT key, value FROM app_state WHERE key LIKE ?', [PREFIX + '%']);
  for (const r of rows) cache[r.key.slice(PREFIX.length)] = r.value;
}

// Wire up DB helpers, load the cached rows, then one-time-migrate any env
// value that isn't yet in the DB (so an existing .env install keeps its config).
async function init({ dbAll, dbRun }) {
  dbAllFn = dbAll;
  dbRunFn = dbRun;
  await load();
  const toMigrate = [];
  for (const key of Object.keys(DEFAULTS)) {
    if (cache[key] === undefined) {
      const e = process.env[key];
      if (e && e.length) toMigrate.push([key, e]);
    }
  }
  if (toMigrate.length) {
    for (const [k, v] of toMigrate) {
      await dbRunFn(
        'INSERT INTO app_state (key, value) VALUES (?, ?) ON CONFLICT(key) DO UPDATE SET value = excluded.value',
        [PREFIX + k, v]
      );
      cache[k] = v;
    }
    console.log(`Konfiguration aus .env in die Datenbank migriert (${toMigrate.length} Werte) — .env wird nicht mehr benötigt.`);
  }
}

// Persist every key (writes all rows, including empty strings, so a cleared
// field is stored as empty and no longer falls back to env/default).
async function saveAll(values) {
  if (!dbRunFn) throw new Error('Konfigurationsspeicher nicht initialisiert.');
  for (const key of Object.keys(DEFAULTS)) {
    const v = values && values[key] != null ? String(values[key]) : '';
    await dbRunFn(
      'INSERT INTO app_state (key, value) VALUES (?, ?) ON CONFLICT(key) DO UPDATE SET value = excluded.value',
      [PREFIX + key, v]
    );
    cache[key] = v;
  }
}

module.exports = { DEFAULTS, FIELDS, get, getAll, ollama, init, load, saveAll };