const AvailableItems = require("../models/available-item.model");
const List = require("../models/list.model.v2");
const { isValidItemType, isValidItemGroup, isValidZone } = require("../constants/classifications");
const { sendError } = require("../utils/http");
const { logError } = require("../utils/logger");

const LEGACY_ITEM_TYPE_MAP = {
  beverages: "beverage",
  snacks: "snack",
};

function parseBoolean(value) {
  return value === true || value === "true" || value === "1";
}

function isCatalogTableMissing(error) {
  return error?.code === "42P01" && /(household_store_items|household_store_available_items)/i.test(error?.message || "");
}

function parseClassificationInput(value) {
  if (value === undefined) {
    return undefined;
  }

  if (value === null) {
    return null;
  }

  if (typeof value === "string") {
    const trimmed = value.trim();
    if (!trimmed) {
      return null;
    }

    if (trimmed === "null") {
      return null;
    }

    if (trimmed.startsWith("{")) {
      try {
        return JSON.parse(trimmed);
      } catch (error) {
        return Symbol.for("invalid-classification-json");
      }
    }

    return trimmed;
  }

  return value;
}

function normalizeClassificationPayload(classification) {
  if (typeof classification === "string") {
    const normalizedItemType = LEGACY_ITEM_TYPE_MAP[classification] || classification;
    return {
      item_type: normalizedItemType,
      item_group: null,
      zone: null,
    };
  }

  if (!classification || typeof classification !== "object" || Array.isArray(classification)) {
    return null;
  }

  const item_type =
    typeof classification.item_type === "string" && classification.item_type.trim() !== ""
      ? classification.item_type.trim()
      : null;
  const item_group =
    typeof classification.item_group === "string" && classification.item_group.trim() !== ""
      ? classification.item_group.trim()
      : null;
  const zone =
    typeof classification.zone === "string" && classification.zone.trim() !== ""
      ? classification.zone.trim()
      : null;

  if (!item_type && !item_group && !zone) {
    return null;
  }

  return { item_type, item_group, zone };
}

function validateClassification(res, classification) {
  if (!classification) {
    return false;
  }

  const { item_type, item_group, zone } = classification;

  if (item_type && !isValidItemType(item_type)) {
    sendError(res, 400, "Invalid item_type");
    return true;
  }

  if (item_group && !item_type) {
    sendError(res, 400, "Item type is required when item group is provided");
    return true;
  }

  if (item_group && !isValidItemGroup(item_type, item_group)) {
    sendError(res, 400, "Invalid item_group for selected item_type");
    return true;
  }

  if (zone && !isValidZone(zone)) {
    sendError(res, 400, "Invalid zone");
    return true;
  }

  return false;
}

function parseItemId(value) {
  const parsed = Number.parseInt(String(value), 10);
  return Number.isInteger(parsed) && parsed > 0 ? parsed : null;
}

exports.getAvailableItems = async (req, res) => {
  try {
    const { householdId, storeId } = req.params;
    const items = await AvailableItems.listAvailableItems(householdId, storeId, req.query.query || "");
    res.json({ items, catalog_ready: true });
  } catch (error) {
    if (isCatalogTableMissing(error)) {
      return res.json({
        items: [],
        catalog_ready: false,
        message: "Store item management is unavailable until the latest database migration is applied.",
      });
    }
    logError(req, "availableItems.getAvailableItems", error);
    sendError(res, 500, "Failed to load available items");
  }
};

exports.createAvailableItem = async (req, res) => {
  try {
    const { householdId, storeId } = req.params;
    const { item_name } = req.body;

    if (!item_name || item_name.trim() === "") {
      return sendError(res, 400, "Item name is required");
    }

    const parsedClassification = parseClassificationInput(req.body.classification);
    if (parsedClassification === Symbol.for("invalid-classification-json")) {
      return sendError(res, 400, "Classification payload must be valid JSON");
    }

    const normalizedClassification = normalizeClassificationPayload(parsedClassification);
    if (validateClassification(res, normalizedClassification)) {
      return;
    }

    const imageBuffer = req.processedImage?.buffer || null;
    const mimeType = req.processedImage?.mimeType || null;

    const item = await AvailableItems.createAvailableItem(
      householdId,
      storeId,
      item_name,
      imageBuffer,
      mimeType
    );

    if (normalizedClassification) {
      await List.upsertClassification(householdId, storeId, item.item_id, {
        ...normalizedClassification,
        confidence: 1.0,
        source: "user",
      });
    }

    const refreshedItem = await AvailableItems.getAvailableItemById(householdId, storeId, item.item_id);

    res.status(201).json({
      message: "Available item added",
      item: refreshedItem,
    });
  } catch (error) {
    if (isCatalogTableMissing(error)) {
      return sendError(
        res,
        503,
        "Store item management is unavailable until the latest database migration is applied"
      );
    }
    logError(req, "availableItems.createAvailableItem", error);
    if (error.code === "23505") {
      return sendError(res, 400, "Available item already exists for this store");
    }
    sendError(res, 500, "Failed to add available item");
  }
};

exports.updateAvailableItem = async (req, res) => {
  try {
    const { householdId, storeId, itemId: rawItemId } = req.params;
    const itemId = parseItemId(rawItemId);

    if (!itemId) {
      return sendError(res, 400, "Item ID must be a positive integer");
    }

    const hasClassificationField = Object.prototype.hasOwnProperty.call(req.body, "classification");
    const parsedClassification = parseClassificationInput(req.body.classification);

    if (parsedClassification === Symbol.for("invalid-classification-json")) {
      return sendError(res, 400, "Classification payload must be valid JSON");
    }

    const normalizedClassification = normalizeClassificationPayload(parsedClassification);
    if (normalizedClassification && validateClassification(res, normalizedClassification)) {
      return;
    }

    const updatedItem = await AvailableItems.updateAvailableItem(householdId, storeId, itemId, {
      itemName: req.body.item_name,
      imageBuffer: req.processedImage?.buffer || null,
      mimeType: req.processedImage?.mimeType || null,
      removeImage: parseBoolean(req.body.remove_image),
    });

    if (!updatedItem) {
      return sendError(res, 404, "Available item not found");
    }

    if (hasClassificationField) {
      if (normalizedClassification) {
        await List.upsertClassification(householdId, storeId, updatedItem.item_id, {
          ...normalizedClassification,
          confidence: 1.0,
          source: "user",
        });
      } else {
        await List.deleteClassification(householdId, storeId, updatedItem.item_id);
      }
    }

    const refreshedItem = await AvailableItems.getAvailableItemById(
      householdId,
      storeId,
      updatedItem.item_id
    );

    res.json({
      message: "Available item updated",
      item: refreshedItem,
    });
  } catch (error) {
    if (isCatalogTableMissing(error)) {
      return sendError(
        res,
        503,
        "Store item management is unavailable until the latest database migration is applied"
      );
    }
    logError(req, "availableItems.updateAvailableItem", error);
    if (error.code === "23505") {
      return sendError(res, 400, "Available item already exists for this store");
    }
    sendError(res, 500, "Failed to update available item");
  }
};

exports.deleteAvailableItem = async (req, res) => {
  try {
    const { householdId, storeId, itemId: rawItemId } = req.params;
    const itemId = parseItemId(rawItemId);

    if (!itemId) {
      return sendError(res, 400, "Item ID must be a positive integer");
    }

    const deleted = await AvailableItems.deleteAvailableItem(householdId, storeId, itemId);

    if (!deleted) {
      return sendError(res, 404, "Store item not found");
    }

    res.json({ message: "Store item deleted" });
  } catch (error) {
    if (isCatalogTableMissing(error)) {
      return sendError(
        res,
        503,
        "Store item management is unavailable until the latest database migration is applied"
      );
    }
    logError(req, "availableItems.deleteAvailableItem", error);
    sendError(res, 500, "Failed to delete store item");
  }
};

exports.importCurrentItems = async (req, res) => {
  try {
    const { householdId, storeId } = req.params;
    const importedCount = await AvailableItems.importCurrentListItems(householdId, storeId);

    res.json({
      message: importedCount > 0 ? "Imported current list items" : "No current list items to import",
      imported_count: importedCount,
    });
  } catch (error) {
    if (isCatalogTableMissing(error)) {
      return sendError(
        res,
        503,
        "Store item management is unavailable until the latest database migration is applied"
      );
    }
    logError(req, "availableItems.importCurrentItems", error);
    sendError(res, 500, "Failed to import current list items");
  }
};