import pg from 'pg'

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

export async function initDb() {
  await pool.query(`
    -- Generic key/value config store (hk-planner/maintenance pattern) — holds
    -- excluded_site_ids, poll_interval_minutes, maintenance integration URL/key, etc.
    CREATE TABLE IF NOT EXISTS config (
      key        TEXT PRIMARY KEY,
      value      JSONB NOT NULL,
      updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );

    -- Zones: rooms (synced from NewBook) and public areas (manual, Phase 3 control).
    -- Single table for the whole device lifetime — Phase 2/3 aircon-specific columns
    -- (cool setpoint, fan mode) land here later as nullable ADD COLUMNs, not a new table.
    CREATE TABLE IF NOT EXISTS zones (
      id                 SERIAL PRIMARY KEY,
      zone_type          TEXT NOT NULL DEFAULT 'room',      -- room | public_area
      source             TEXT NOT NULL DEFAULT 'manual',    -- newbook | manual
      newbook_site_id    TEXT UNIQUE,
      name               TEXT NOT NULL,
      active             BOOLEAN NOT NULL DEFAULT TRUE,     -- soft-deactivate on NewBook sync, never hard delete
      -- TRV temps + offsets: NULL = inherit the global 'hvac_defaults' config template (see seedDefaults()).
      -- A non-NULL value here is an explicit per-room override.
      occupied_temp      NUMERIC(4,1),
      vacant_temp        NUMERIC(4,1),
      heating_offset_min INT,                                -- minutes before arrival to start heating
      cooling_offset_min INT,                                -- minutes after departure to stop (negative = before checkout)
      -- Aircon template overrides — same inherit-if-NULL relationship to hvac_defaults.ac_occupied/ac_vacant.
      ac_occupied_power     TEXT,                             -- 'on' | 'off'
      ac_occupied_mode      TEXT,                             -- cool | heat | fan | auto | dry
      ac_occupied_setpoint  NUMERIC(4,1),
      ac_occupied_fan_speed TEXT,                             -- low | medium | high | powerful
      ac_vacant_power       TEXT,
      ac_vacant_mode        TEXT,
      ac_vacant_setpoint    NUMERIC(4,1),
      ac_vacant_fan_speed   TEXT,
      auto_mode          BOOLEAN NOT NULL DEFAULT TRUE,
      sync_valves        BOOLEAN NOT NULL DEFAULT TRUE,     -- sync guest setpoint changes across valves in the same zone
      exclude_bathroom   BOOLEAN NOT NULL DEFAULT TRUE,     -- bathroom valve excluded from guest-adjustment sync
      created_at         TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );

    -- Device mapping — one row per physical device, assigned to a zone by staff via
    -- the Devices onboarding flow (never auto-mapped from device naming conventions).
    CREATE TABLE IF NOT EXISTS zone_devices (
      id                  SERIAL PRIMARY KEY,
      zone_id             INT REFERENCES zones(id) ON DELETE SET NULL,
      device_type         TEXT NOT NULL,     -- shelly_trv | mhi_modbus | midea | daikin | home_assistant
      external_ref        TEXT NOT NULL,     -- MAC / Modbus address / LAN device ID / HA entity_id
      discovered_name      TEXT,             -- raw name/label from the device — display-only, never parsed
      location            TEXT,              -- bedroom / bathroom / living / free text, set by staff
      maintenance_asset_id INT,              -- set once "Create asset in Maintenance" succeeds (Phase 1: stub, always NULL)
      last_seen           TIMESTAMPTZ,
      battery_pct         INT,
      health_state        TEXT NOT NULL DEFAULT 'healthy',  -- healthy | degraded | poor | unresponsive | calibration_error
      wifi_rssi           INT,
      current_target_temp NUMERIC(4,1),
      target_origin       TEXT,              -- automation | guest | pending | unknown (Shelly source field)
      device_ip           TEXT,              -- for the HTTP wake-up fallback
      created_at          TIMESTAMPTZ NOT NULL DEFAULT NOW(),
      updated_at          TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );
    CREATE INDEX IF NOT EXISTS zone_devices_zone_idx ON zone_devices (zone_id);
    CREATE UNIQUE INDEX IF NOT EXISTS zone_devices_type_ref_idx ON zone_devices (device_type, external_ref);

    -- Two photo slots per device (device photo + serial/model plate) — same pattern
    -- as maintenance's task_photos: multipart + sharp, uploads_data volume.
    CREATE TABLE IF NOT EXISTS device_photos (
      id          SERIAL PRIMARY KEY,
      device_id   INT NOT NULL REFERENCES zone_devices(id) ON DELETE CASCADE,
      file_name   TEXT NOT NULL,
      file_path   TEXT NOT NULL,
      mime_type   TEXT,
      file_size   INT,
      photo_type  TEXT NOT NULL DEFAULT 'device',  -- device | serial_plate
      uploaded_by TEXT,
      uploaded_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );
    CREATE INDEX IF NOT EXISTS device_photos_device_idx ON device_photos (device_id);

    -- Minimal, TTL'd booking cache — room-planner style (no full booking mirror).
    -- Kept per-zone so a NewBook fetch failure can fall back to the last successful
    -- read instead of treating "fetch failed" as "no booking" (fail-safe requirement).
    CREATE TABLE IF NOT EXISTS booking_cache (
      zone_id      INT PRIMARY KEY REFERENCES zones(id) ON DELETE CASCADE,
      booking_data JSONB,
      fetched_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );

    -- Persisted current room state — survives backend restarts, and lets the
    -- scheduler apply setpoints only at state *transitions* (never poll-and-reassert
    -- during 'occupied', which would stomp guest button/WS adjustments).
    CREATE TABLE IF NOT EXISTS zone_state (
      zone_id            INT PRIMARY KEY REFERENCES zones(id) ON DELETE CASCADE,
      room_state         TEXT NOT NULL DEFAULT 'vacant',   -- vacant | booked | heating_up | occupied | cooling_down
      last_booking_status TEXT,
      last_transition_at TIMESTAMPTZ,
      -- Dashboard's takeoff/landing/stayover icon + night-count, computed alongside
      -- room_state from whichever booking is currently governing the room (see
      -- resolveGoverningBooking() in lib/scheduler.js). NULL when there's no booking
      -- whose stay actually covers today (room_state 'booked' from a future arrival,
      -- or 'vacant').
      booking_kind       TEXT,                              -- arrival | departure | stayover | NULL
      current_night      INT,
      total_nights       INT,
      has_next_booking   BOOLEAN NOT NULL DEFAULT FALSE,     -- turnover hint: another booking follows a departure today
      -- Only set when room_state = 'vacant': nights until the next known arrival
      -- within the scheduler's fetch window, or NULL if nothing was found in that
      -- window at all (displayed as an open-ended "7+ nights" rather than a count).
      vacant_nights      INT,
      updated_at         TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );

    -- Rolling log of state transitions, manual overrides, sync runs and errors.
    CREATE TABLE IF NOT EXISTS activity_log (
      id         SERIAL PRIMARY KEY,
      zone_id    INT REFERENCES zones(id) ON DELETE CASCADE,
      event_type TEXT NOT NULL,   -- transition | override | sync | device_command | error
      from_state TEXT,
      to_state   TEXT,
      note       TEXT,
      source     TEXT NOT NULL DEFAULT 'scheduler',  -- scheduler | manual | sync
      user_email TEXT,
      created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );
    CREATE INDEX IF NOT EXISTS activity_log_zone_idx ON activity_log (zone_id, created_at DESC);

    -- MHI Modbus TCP gateways (Intesis SuperLink -> Modbus, see
    -- lib/drivers/mhi-profiles/intesis-mhi-modbus.js). Connection details are
    -- UI config; the per-unit register map is ground truth from a MAPS "Excel
    -- signals file" import (lib/mhi-xlsx-import.js), never derived from
    -- room/IU at runtime. imported_units stages the last parsed export for
    -- staff review — importing never auto-creates zone_devices rows, staff
    -- explicitly assign each unit to a zone (see /units/:unitIndex/assign).
    CREATE TABLE IF NOT EXISTS mhi_gateways (
      id                SERIAL PRIMARY KEY,
      name              TEXT NOT NULL,
      host              TEXT NOT NULL,
      port              INT NOT NULL DEFAULT 502,
      slave_id          INT NOT NULL DEFAULT 1,
      address_base      INT NOT NULL DEFAULT 0,
      imported_filename TEXT,
      imported_units    JSONB,
      imported_at       TIMESTAMPTZ,
      created_at        TIMESTAMPTZ NOT NULL DEFAULT NOW(),
      updated_at        TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );
  `)

  // zone_devices predates MHI support — nullable columns added as an ALTER,
  // same pattern as auth/calendar/wages db.js (ADD COLUMN IF NOT EXISTS keeps
  // initDb() idempotent without a separate migrations runner).
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS mhi_gateway_id INT REFERENCES mhi_gateways(id) ON DELETE SET NULL`)
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS mhi_unit_index INT`)
  // Informational SuperLink IU hint only, shown in the UI — NEVER used for register math
  // (the register base can only be known from an actual MAPS import; see the profile file).
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS mhi_iu_address INT`)
  // The resolved per-unit `fields` object straight from the MAPS import for this device
  // (e.g. { setpoint: { address, active, readWrite }, roomTemp: {...}, ... }) — stored
  // directly rather than re-derived from profile+index at runtime, so there's no drift
  // between what was imported and what the driver assumes.
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS mhi_register_map JSONB`)

  // Dashboard live-status cache — populated by mqtt.js (shelly_trv: current_room_temp,
  // heating_active) and ac-poller.js (mhi_modbus: everything else). Nullable, since
  // which columns apply depends on device_type and no reading has necessarily arrived yet.
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS current_room_temp NUMERIC(4,1)`)
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS heating_active BOOLEAN`)
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS power_state TEXT`)
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS current_mode TEXT`)
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS fan_speed TEXT`)
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS remote_locked BOOLEAN`)
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS status_updated_at TIMESTAMPTZ`)

  // Live TRV firmware (SHTRV-01 v2.2.4, confirmed 2026-08-25) publishes a combined
  // status blob with no guest-vs-automation 'source' field the old archived logic
  // relied on. Guest detection is done by diffing an incoming target_t against the
  // last value hvac itself commanded — stamped here right before every publish, read
  // back in mqtt.js's status handler. A mismatch = guest changed it via the dial.
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS last_commanded_target_t NUMERIC(4,1)`)

  // Valve position (0-100, from thermostats[0].pos on shellies/<id>/info) — >0 already
  // drives heating_active, but the modal wants the raw percentage too.
  await pool.query(`ALTER TABLE zone_devices ADD COLUMN IF NOT EXISTS valve_position INT`)

  // Default-template rollout: existing installs created occupied_temp/vacant_temp/
  // heating_offset_min/cooling_offset_min as NOT NULL with a hardcoded default — relax
  // that so NULL can mean "inherit the global hvac_defaults template" (see seedDefaults()
  // below). Every existing room's current value is preserved as its explicit override —
  // nothing changes behaviourally for any room on deploy. DROP NOT NULL/DROP DEFAULT are
  // no-ops (not errors) if already relaxed, so this stays safe to run on every startup.
  for (const col of ['occupied_temp', 'vacant_temp', 'heating_offset_min', 'cooling_offset_min']) {
    await pool.query(`ALTER TABLE zones ALTER COLUMN ${col} DROP NOT NULL`)
    await pool.query(`ALTER TABLE zones ALTER COLUMN ${col} DROP DEFAULT`)
  }
  await pool.query(`ALTER TABLE zones ADD COLUMN IF NOT EXISTS ac_occupied_power TEXT`)
  await pool.query(`ALTER TABLE zones ADD COLUMN IF NOT EXISTS ac_occupied_mode TEXT`)
  await pool.query(`ALTER TABLE zones ADD COLUMN IF NOT EXISTS ac_occupied_setpoint NUMERIC(4,1)`)
  await pool.query(`ALTER TABLE zones ADD COLUMN IF NOT EXISTS ac_occupied_fan_speed TEXT`)
  await pool.query(`ALTER TABLE zones ADD COLUMN IF NOT EXISTS ac_vacant_power TEXT`)
  await pool.query(`ALTER TABLE zones ADD COLUMN IF NOT EXISTS ac_vacant_mode TEXT`)
  await pool.query(`ALTER TABLE zones ADD COLUMN IF NOT EXISTS ac_vacant_setpoint NUMERIC(4,1)`)
  await pool.query(`ALTER TABLE zones ADD COLUMN IF NOT EXISTS ac_vacant_fan_speed TEXT`)

  await pool.query(`ALTER TABLE zone_state ADD COLUMN IF NOT EXISTS booking_kind TEXT`)
  await pool.query(`ALTER TABLE zone_state ADD COLUMN IF NOT EXISTS current_night INT`)
  await pool.query(`ALTER TABLE zone_state ADD COLUMN IF NOT EXISTS total_nights INT`)
  await pool.query(`ALTER TABLE zone_state ADD COLUMN IF NOT EXISTS has_next_booking BOOLEAN NOT NULL DEFAULT FALSE`)
  await pool.query(`ALTER TABLE zone_state ADD COLUMN IF NOT EXISTS vacant_nights INT`)

  await seedDefaults()
}

// Global fallback template for every room's occupied/vacant TRV + aircon state, used
// wherever a zone's own override column is NULL. Structured as a single 'hvac_defaults'
// config value (not a dedicated table) since the generic config store already holds
// arbitrary JSONB per key — see routes/config.js.
export const DEFAULT_HVAC_TEMPLATE = {
  arrival_prep_offset_min:   120,    // minutes before arrival to start heating
  departure_prep_offset_min: -30,    // minutes after departure to start cooling (negative = before checkout)
  trv_occupied_temp: 22.0,
  trv_vacant_temp:   16.0,
  ac_occupied: { power: 'on',  mode: 'cool', setpoint: 22.0, fan_speed: 'medium' },
  ac_vacant:   { power: 'off', mode: 'cool', setpoint: 18.0, fan_speed: 'low' },
  // Weather compensation — ordered ascending by peak_above_c. At an occupied-state
  // transition, the scheduler picks the HIGHEST tier whose threshold today's forecast
  // peak clears and uses its template instead of ac_occupied above; below every
  // threshold (or if no forecast is available), ac_occupied is used unchanged. See
  // lib/weather.js and resolveAcTemplate() in lib/scheduler.js.
  ac_occupied_tiers: [
    { name: 'warm',     peak_above_c: 24, power: 'off', mode: 'cool', setpoint: 20.0, fan_speed: 'medium' },
    { name: 'hot',      peak_above_c: 28, power: 'on',  mode: 'cool', setpoint: 20.0, fan_speed: 'high' },
    { name: 'heatwave', peak_above_c: 32, power: 'on',  mode: 'cool', setpoint: 20.0, fan_speed: 'powerful' },
  ],
}

async function seedDefaults() {
  const defaults = {
    automation_enabled:     true,   // master kill switch — overrides every zone's own auto_mode
    excluded_site_ids:      [],
    poll_interval_minutes:  10,     // matches the old integration's DEFAULT_SCAN_INTERVAL
    default_arrival_time:   '15:00:00',
    default_departure_time: '10:00:00',
    maintenance_url:        '',
    maintenance_api_key:    '',
    hvac_defaults:          DEFAULT_HVAC_TEMPLATE,
  }
  for (const [key, value] of Object.entries(defaults)) {
    await pool.query(
      `INSERT INTO config (key, value) VALUES ($1, $2) ON CONFLICT (key) DO NOTHING`,
      [key, JSON.stringify(value)]
    )
  }
}

export async function getConfig(key, fallback = null) {
  const { rows } = await pool.query('SELECT value FROM config WHERE key = $1', [key])
  return rows.length ? rows[0].value : fallback
}

export async function setConfig(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)]
  )
}

export async function logActivity(zoneId, eventType, { fromState, toState, note, source = 'scheduler', userEmail } = {}) {
  await pool.query(
    `INSERT INTO activity_log (zone_id, event_type, from_state, to_state, note, source, user_email)
     VALUES ($1,$2,$3,$4,$5,$6,$7)`,
    [zoneId, eventType, fromState || null, toState || null, note || null, source, userEmail || null]
  )
}