const { query } = require('../config/db');

/**
 * Получить канал со всеми связанными настройками (style + schedule).
 */
async function getFullChannel(channelId, userId = null) {
  const filter = userId ? `AND user_id=$2` : '';
  const params = userId ? [channelId, userId] : [channelId];

  const { rows } = await query(
    `SELECT c.*,
       to_jsonb(s.*) - 'channel_id' - 'updated_at' AS style,
       to_jsonb(sch.*) - 'channel_id' - 'updated_at' AS schedule
     FROM channels c
     LEFT JOIN channel_style s ON s.channel_id = c.id
     LEFT JOIN channel_schedule sch ON sch.channel_id = c.id
     WHERE c.id=$1 ${filter}`,
    params
  );
  return rows[0] || null;
}

async function listChannels(userId) {
  const { rows } = await query(
    `SELECT c.*,
       to_jsonb(s.*) - 'channel_id' - 'updated_at' AS style,
       to_jsonb(sch.*) - 'channel_id' - 'updated_at' AS schedule
     FROM channels c
     LEFT JOIN channel_style s ON s.channel_id = c.id
     LEFT JOIN channel_schedule sch ON sch.channel_id = c.id
     WHERE c.user_id=$1
     ORDER BY c.created_at DESC`,
    [userId]
  );
  return rows;
}

/**
 * Создать канал — заполняет 3 таблицы транзакционно.
 */
async function createChannel(userId, data) {
  const {
    name, tg_channel_id, tg_username, bot_token,
    niche, audience, goal, language, region,
    style = {}, schedule = {},
  } = data;

  if (!name) throw new Error('name is required');

  const client = await require('../config/db').query;

  // INSERT channel
  const { rows: chRows } = await query(
    `INSERT INTO channels
       (user_id, name, tg_channel_id, tg_username, bot_token, niche, audience, goal, language, region)
     VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10)
     RETURNING *`,
    [
      userId, name, tg_channel_id || null, tg_username || null, bot_token || null,
      niche || null, audience || null, goal || 'educational',
      language || 'ru', region || 'ru',
    ]
  );
  const channel = chRows[0];

  // INSERT style
  await query(
    `INSERT INTO channel_style
       (channel_id, tone, tone_custom, formality, humor, post_length, structure,
        emoji_level, hashtags_mode, cta_mode, example_posts, banned_words, banned_topics, expertise)
     VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14)`,
    [
      channel.id,
      style.tone || 'friendly',
      style.tone_custom || null,
      style.formality || 'informal',
      style.humor || 'moderate',
      style.post_length || 'medium',
      style.structure || 'mixed',
      style.emoji_level || 'moderate',
      style.hashtags_mode || 'end',
      style.cta_mode || 'sometimes',
      JSON.stringify(style.example_posts || []),
      JSON.stringify(style.banned_words || []),
      JSON.stringify(style.banned_topics || []),
      JSON.stringify(style.expertise || []),
    ]
  );

  // INSERT schedule
  await query(
    `INSERT INTO channel_schedule
       (channel_id, posts_per_day, time_slots, timezone, rubrics, sources, auto_publish)
     VALUES ($1,$2,$3,$4,$5,$6,$7)`,
    [
      channel.id,
      schedule.posts_per_day || 1,
      JSON.stringify(schedule.time_slots || []),
      schedule.timezone || 'Europe/Moscow',
      JSON.stringify(schedule.rubrics || []),
      JSON.stringify(schedule.sources || []),
      schedule.auto_publish || false,
    ]
  );

  return getFullChannel(channel.id);
}

/**
 * Обновить канал (только то что передано).
 */
async function updateChannel(channelId, userId, data) {
  const { style, schedule, ...channelFields } = data;

  // обновить channels
  if (Object.keys(channelFields).length) {
    const fields = ['name', 'tg_channel_id', 'tg_username', 'bot_token',
                    'niche', 'audience', 'goal', 'language', 'region', 'is_active',
                    'vk_access_token', 'ai_style_prompt', 'image_quality',
                    'auto_draft_enabled', 'auto_draft_count', 'auto_draft_time'];
    const updates = fields.filter(f => channelFields[f] !== undefined);
    if (updates.length) {
      const setClauses = updates.map((f, i) => `${f}=$${i + 1}`).join(', ');
      const values = updates.map(f => channelFields[f]);
      values.push(channelId, userId);
      await query(
        `UPDATE channels SET ${setClauses}, updated_at=NOW()
         WHERE id=$${values.length - 1} AND user_id=$${values.length}`,
        values
      );
    }
  }

  // обновить style
  if (style && Object.keys(style).length) {
    const fields = ['tone', 'tone_custom', 'formality', 'humor', 'post_length',
                    'structure', 'emoji_level', 'hashtags_mode', 'cta_mode',
                    'example_posts', 'banned_words', 'banned_topics', 'expertise',
                    'image_enabled', 'image_style', 'image_palette',
                    'image_custom_colors', 'image_prompt_instructions'];
    const updates = fields.filter(f => style[f] !== undefined);
    if (updates.length) {
      const setClauses = updates.map((f, i) => {
        const isJson = ['example_posts', 'banned_words', 'banned_topics', 'expertise'].includes(f);
        return `${f}=$${i + 1}${isJson ? '::jsonb' : ''}`;
      }).join(', ');
      const values = updates.map(f => {
        const isJson = ['example_posts', 'banned_words', 'banned_topics', 'expertise'].includes(f);
        return isJson ? JSON.stringify(style[f]) : style[f];
      });
      values.push(channelId);
      await query(
        `UPDATE channel_style SET ${setClauses}, updated_at=NOW() WHERE channel_id=$${values.length}`,
        values
      );
    }
  }

  // обновить schedule
  if (schedule && Object.keys(schedule).length) {
    const fields = ['posts_per_day', 'time_slots', 'timezone', 'rubrics', 'sources', 'auto_publish'];
    const updates = fields.filter(f => schedule[f] !== undefined);
    if (updates.length) {
      const setClauses = updates.map((f, i) => {
        const isJson = ['time_slots', 'rubrics', 'sources'].includes(f);
        return `${f}=$${i + 1}${isJson ? '::jsonb' : ''}`;
      }).join(', ');
      const values = updates.map(f => {
        const isJson = ['time_slots', 'rubrics', 'sources'].includes(f);
        return isJson ? JSON.stringify(schedule[f]) : schedule[f];
      });
      values.push(channelId);
      await query(
        `UPDATE channel_schedule SET ${setClauses}, updated_at=NOW() WHERE channel_id=$${values.length}`,
        values
      );
    }
  }

  return getFullChannel(channelId, userId);
}

async function deleteChannel(channelId, userId) {
  await query(`DELETE FROM channels WHERE id=$1 AND user_id=$2`, [channelId, userId]);
  return { ok: true };
}

module.exports = {
  getChannel: getFullChannel,   // алиас для обратной совместимости
  getFullChannel,
  listChannels,
  createChannel,
  updateChannel,
  deleteChannel,
};