const pool = require("../db/pool");

function normalizeItemName(itemName) {
  return String(itemName || "").trim().toLowerCase();
}

async function getHouseholdStoreItemRecord(householdId, storeId, itemId) {
  const result = await pool.query(
    `WITH latest_list_items AS (
       SELECT DISTINCT ON (hl.household_store_item_id)
         hl.household_store_item_id,
         hl.custom_image,
         hl.custom_image_mime_type,
         hl.modified_on,
         hl.id
       FROM household_lists hl
       WHERE hl.household_id = $1
         AND hl.store_id = $2
       ORDER BY hl.household_store_item_id, hl.modified_on DESC NULLS LAST, hl.id DESC
     )
     SELECT
       hsi.id AS item_id,
       hsi.name AS item_name,
       ENCODE(COALESCE(hsi.custom_image, lli.custom_image), 'base64') AS item_image,
       COALESCE(hsi.custom_image_mime_type, lli.custom_image_mime_type) AS image_mime_type,
       hic.item_type,
       hic.item_group,
       hic.zone
     FROM household_store_items hsi
     LEFT JOIN latest_list_items lli ON lli.household_store_item_id = hsi.id
     LEFT JOIN household_item_classifications hic
       ON hic.household_id = hsi.household_id
       AND hic.store_id = hsi.store_id
       AND hic.household_store_item_id = hsi.id
     WHERE hsi.household_id = $1
       AND hsi.store_id = $2
       AND hsi.id = $3`,
    [householdId, storeId, itemId]
  );

  return result.rows[0] || null;
}

async function findOrCreateHouseholdStoreItem(householdId, storeId, itemName) {
  const normalizedName = normalizeItemName(itemName);
  const existing = await pool.query(
    `SELECT id, name
     FROM household_store_items
     WHERE household_id = $1
       AND store_id = $2
       AND normalized_name = $3`,
    [householdId, storeId, normalizedName]
  );

  if (existing.rowCount > 0) {
    return {
      itemId: existing.rows[0].id,
      itemName: existing.rows[0].name,
    };
  }

  const created = await pool.query(
    `INSERT INTO household_store_items
      (household_id, store_id, name, normalized_name, updated_at)
     VALUES ($1, $2, $3, $4, NOW())
     RETURNING id, name`,
    [householdId, storeId, normalizedName, normalizedName]
  );

  return {
    itemId: created.rows[0].id,
    itemName: created.rows[0].name,
  };
}

exports.listAvailableItems = async (householdId, storeId, query = "") => {
  const trimmedQuery = String(query || "").trim();
  const values = [householdId, storeId];
  let filterClause = "";

  if (trimmedQuery) {
    values.push(`%${trimmedQuery}%`);
    filterClause = "AND hsi.name ILIKE $3";
  }

  const result = await pool.query(
    `WITH latest_list_items AS (
       SELECT DISTINCT ON (hl.household_store_item_id)
         hl.household_store_item_id,
         hl.custom_image,
         hl.custom_image_mime_type,
         hl.modified_on,
         hl.id
       FROM household_lists hl
       WHERE hl.household_id = $1
         AND hl.store_id = $2
       ORDER BY hl.household_store_item_id, hl.modified_on DESC NULLS LAST, hl.id DESC
     )
     SELECT
       hsi.id AS item_id,
       hsi.name AS item_name,
       ENCODE(COALESCE(hsi.custom_image, lli.custom_image), 'base64') AS item_image,
       COALESCE(hsi.custom_image_mime_type, lli.custom_image_mime_type) AS image_mime_type,
       hic.item_type,
       hic.item_group,
       hic.zone,
       (
         hsi.custom_image IS NOT NULL
         OR hic.household_store_item_id IS NOT NULL
       ) AS has_managed_settings
     FROM household_store_items hsi
     LEFT JOIN latest_list_items lli ON lli.household_store_item_id = hsi.id
     LEFT JOIN household_item_classifications hic
       ON hic.household_id = hsi.household_id
       AND hic.store_id = hsi.store_id
       AND hic.household_store_item_id = hsi.id
     WHERE hsi.household_id = $1
       AND hsi.store_id = $2
       ${filterClause}
     ORDER BY hsi.name ASC
     LIMIT 100`,
    values
  );

  return result.rows;
};

exports.getAvailableItemById = async (householdId, storeId, itemId) =>
  getHouseholdStoreItemRecord(householdId, storeId, itemId);

exports.getAvailableItemImageByName = async (householdId, storeId, itemName) => {
  const normalizedName = normalizeItemName(itemName);
  const result = await pool.query(
    `SELECT
      id AS item_id,
      name AS item_name,
      custom_image,
      custom_image_mime_type
    FROM household_store_items
    WHERE household_id = $1
      AND store_id = $2
      AND normalized_name = $3`,
    [householdId, storeId, normalizedName]
  );

  return result.rows[0] || null;
};

exports.createAvailableItem = async (
  householdId,
  storeId,
  itemName,
  imageBuffer = null,
  mimeType = null
) => {
  const { itemId } = await findOrCreateHouseholdStoreItem(householdId, storeId, itemName);

  if (imageBuffer && mimeType) {
    await pool.query(
      `UPDATE household_store_items
       SET custom_image = $1,
           custom_image_mime_type = $2,
           updated_at = NOW()
       WHERE id = $3
         AND household_id = $4
         AND store_id = $5`,
      [imageBuffer, mimeType, itemId, householdId, storeId]
    );
  }

  return getHouseholdStoreItemRecord(householdId, storeId, itemId);
};

exports.updateAvailableItem = async (householdId, storeId, itemId, updates = {}) => {
  const {
    itemName,
    imageBuffer,
    mimeType,
    removeImage = false,
  } = updates;

  const assignments = ["updated_at = NOW()"];
  const values = [householdId, storeId, itemId];
  let parameterIndex = values.length;

  if (itemName !== undefined && String(itemName).trim() !== "") {
    const normalizedName = normalizeItemName(itemName);
    parameterIndex += 1;
    assignments.push(`name = $${parameterIndex}`);
    values.push(normalizedName);

    parameterIndex += 1;
    assignments.push(`normalized_name = $${parameterIndex}`);
    values.push(normalizedName);
  }

  if (removeImage) {
    assignments.push("custom_image = NULL", "custom_image_mime_type = NULL");
  } else if (imageBuffer && mimeType) {
    parameterIndex += 1;
    assignments.push(`custom_image = $${parameterIndex}`);
    values.push(imageBuffer);

    parameterIndex += 1;
    assignments.push(`custom_image_mime_type = $${parameterIndex}`);
    values.push(mimeType);
  }

  const result = await pool.query(
    `UPDATE household_store_items
     SET ${assignments.join(", ")}
     WHERE household_id = $1
       AND store_id = $2
       AND id = $3
     RETURNING id`,
    values
  );

  if (result.rowCount === 0) {
    return null;
  }

  return getHouseholdStoreItemRecord(householdId, storeId, result.rows[0].id);
};

exports.deleteAvailableItem = async (householdId, storeId, itemId) => {
  const result = await pool.query(
    `DELETE FROM household_store_items
     WHERE household_id = $1
       AND store_id = $2
       AND id = $3`,
    [householdId, storeId, itemId]
  );

  return result.rowCount > 0;
};

exports.importCurrentListItems = async (householdId, storeId) => {
  const result = await pool.query(
    `INSERT INTO household_store_items
      (household_id, store_id, name, normalized_name, custom_image, custom_image_mime_type, updated_at)
     SELECT DISTINCT ON (hl.household_store_item_id)
      hl.household_id,
      hl.store_id,
      hsi.name,
      hsi.normalized_name,
      hsi.custom_image,
      hsi.custom_image_mime_type,
      NOW()
     FROM household_lists hl
     JOIN household_store_items hsi ON hsi.id = hl.household_store_item_id
     WHERE hl.household_id = $1
       AND hl.store_id = $2
     ON CONFLICT (household_id, store_id, normalized_name) DO NOTHING
     RETURNING id`,
    [householdId, storeId]
  );

  return result.rowCount;
};

exports.hasAvailableItems = async (householdId, storeId) => {
  const result = await pool.query(
    `SELECT 1
     FROM household_store_items
     WHERE household_id = $1
       AND store_id = $2
     LIMIT 1`,
    [householdId, storeId]
  );

  return result.rowCount > 0;
};