import pg from 'pg'

const { Pool } = pg
export const pool = new Pool({ connectionString: process.env.DATABASE_URL })

export async function initDb() {
  await pool.query(`
    -- App-wide key/value status (last fetch time/provider/error) — same KV pattern as
    -- tasks' config table, just used for status rather than user-facing settings since
    -- the real settings (hotel_location, met_office key) live centrally in the
    -- shared 'settings' app, not here.
    CREATE TABLE IF NOT EXISTS status (
      key        TEXT PRIMARY KEY,
      value      JSONB NOT NULL,
      updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );

    -- One row per forecast data point. 'resolution' is which display tier it belongs
    -- to: 'hourly' (today, full day), '3hourly' (next 2 days), 'daily' (days 4-7).
    -- temp_min_c only populated for 'daily' rows (hourly/3hourly are point-in-time).
    -- Each refresh cycle replaces the full set for a resolution in one transaction
    -- (see lib/weather-fetch.js) rather than patching individual rows, so stale points
    -- from a provider that later drops out of range never linger.
    CREATE TABLE IF NOT EXISTS forecast_points (
      id             SERIAL PRIMARY KEY,
      resolution     TEXT NOT NULL,
      ts             TIMESTAMPTZ NOT NULL,
      temp_c         NUMERIC NOT NULL,
      temp_min_c     NUMERIC,
      feels_like_c   NUMERIC,
      precip_prob    NUMERIC,
      wind_speed_mph NUMERIC,
      wind_dir_deg   NUMERIC,
      icon           TEXT NOT NULL,
      condition_text TEXT,
      source         TEXT NOT NULL,
      fetched_at     TIMESTAMPTZ NOT NULL DEFAULT NOW(),
      UNIQUE (resolution, ts)
    );
    CREATE INDEX IF NOT EXISTS forecast_points_res_ts_idx ON forecast_points (resolution, ts);

    -- Sunrise/sunset for today + the next 2 days — shown next to each day's label
    -- on the display. Only 3 rows at a time; replaced wholesale each refresh cycle
    -- alongside forecast_points (see lib/weather-fetch.js's replaceAstro()).
    CREATE TABLE IF NOT EXISTS forecast_astro (
      date       TEXT PRIMARY KEY,
      sunrise    TIMESTAMPTZ,
      sunset     TIMESTAMPTZ,
      fetched_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );

    -- User-editable display settings (currently just display_title). Separate from
    -- the status table (fetch bookkeeping, not user-facing) -- same KV shape as
    -- tasks' config table. A missing/null display_title falls back to
    -- VITE_HOTEL_NAME at the frontend (see routes/config.js), so an unconfigured
    -- app still shows something sensible without requiring a rebuild.
    CREATE TABLE IF NOT EXISTS config (
      key        TEXT PRIMARY KEY,
      value      JSONB NOT NULL,
      updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );
  `)

  // wind_dir_deg was added to forecast_points after the first deploy already ran —
  // CREATE TABLE IF NOT EXISTS above is a no-op against an existing table, it does
  // NOT retroactively add new columns, so this needs its own explicit migration.
  // forecast_astro/config didn't need this since they're whole new tables, which
  // CREATE TABLE IF NOT EXISTS does handle correctly on an existing database.
  await pool.query(`ALTER TABLE forecast_points ADD COLUMN IF NOT EXISTS wind_dir_deg NUMERIC`)
}

export async function getStatus() {
  const { rows } = await pool.query('SELECT key, value FROM status')
  return Object.fromEntries(rows.map(r => [r.key, r.value]))
}

export async function setStatus(key, value) {
  await pool.query(
    `INSERT INTO status (key, value, updated_at) VALUES ($1, $2, NOW())
     ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value, updated_at = NOW()`,
    [key, JSON.stringify(value)]
  )
}

export async function getConfig() {
  const { rows } = await pool.query('SELECT key, value FROM config')
  return Object.fromEntries(rows.map(r => [r.key, r.value]))
}

export async function setConfigValue(key, value) {
  await pool.query(
    `INSERT INTO config (key, value, updated_at) VALUES ($1, $2, NOW())
     ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value, updated_at = NOW()`,
    [key, JSON.stringify(value)]
  )
}