using MySqlConnector;
using UtopiaCanteenSystem.Models;

namespace UtopiaCanteenSystem.Services;

/// <summary>
/// Fetches lunch menu from HRMS: lunch_menu_week (by location_site_id) → lunch_menu_item → menu_item.
/// Uses IConfigService.GetHrmsLookupConnectionString(). Only current week is considered.
/// </summary>
//public class MenuLookupService : IMenuLookupService
//{
//    private readonly IConfigService _configService;

//    public MenuLookupService(IConfigService configService)
//    {
//        _configService = configService;
//    }

//    /// <inheritdoc />
//    public async Task<IReadOnlyList<HrmsMenuItem>> GetMenuItemsForSiteAsync(int siteIdNumeric, CancellationToken cancellationToken = default)
//    {
//        // Backwards-compatible: use today's local date.
//        return await GetMenuItemsForSiteAndDateAsync(siteIdNumeric, DateTime.Today, cancellationToken).ConfigureAwait(false);
//    }

//    /// <inheritdoc />
//    public async Task<IReadOnlyList<HrmsMenuItem>> GetMenuItemsForSiteAndDateAsync(int siteIdNumeric, DateTime menuDateLocal, CancellationToken cancellationToken = default)
//    {
//        var connectionString = _configService.GetHrmsLookupConnectionString();
//        if (string.IsNullOrWhiteSpace(connectionString))
//            return Array.Empty<HrmsMenuItem>();

//        //const string sql = @"
//        //    SELECT DISTINCT mi.id, mi.item_name, mi.item_type, mi.price
//        //    FROM lunch_menu_week w
//        //    JOIN lunch_menu_item li ON li.lunch_menu_week_id = w.id
//        //    JOIN menu_item mi ON mi.id = li.menu_item_id
//        //    WHERE w.location_site_id = @siteId
//        //      AND CURDATE() BETWEEN w.week_start_date AND w.week_end_date
//        //    ORDER BY mi.item_type, mi.item_name";

//        const string sql = @"
//    SELECT
//        mi.id,
//        mi.item_name,
//        mi.item_type,
//        mi.price,
//        li.menu_date,
//        li.day_of_week
//    FROM lunch_menu_week w
//    JOIN lunch_menu_item li ON li.lunch_menu_week_id = w.id
//    JOIN menu_item mi ON mi.id = li.menu_item_id
//    WHERE w.location_site_id = @siteId
//      AND @menuDate BETWEEN w.week_start_date AND w.week_end_date
//      AND li.menu_date = @menuDate
//    ORDER BY mi.item_name;";

//        //const string sql = @"
//        //    SELECT
//        //        mi.id,
//        //        mi.item_name,
//        //        mi.item_type,
//        //        mi.price,
//        //        li.meal_name,
//        //        li.menu_date,
//        //        li.day_of_week
//        //    FROM lunch_menu_week w
//        //    JOIN lunch_menu_item li ON li.lunch_menu_week_id = w.id
//        //    JOIN menu_item mi ON mi.id = li.menu_item_id
//        //    WHERE w.location_site_id = @siteId
//        //      AND @menuDate BETWEEN w.week_start_date AND w.week_end_date
//        //      AND li.menu_date = @menuDate
//        //    ORDER BY li.meal_name, mi.item_name;";

//        await using var conn = new MySqlConnection(connectionString);
//        await conn.OpenAsync(cancellationToken).ConfigureAwait(false);
//        await using var cmd = new MySqlCommand(sql, conn);
//        cmd.Parameters.AddWithValue("@siteId", siteIdNumeric);
//        cmd.Parameters.AddWithValue("@menuDate", menuDateLocal.Date);

//        var list = new List<HrmsMenuItem>();
//        await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
//        while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
//        {
//            //list.Add(new HrmsMenuItem
//            //{
//            //    MenuItemId = reader.IsDBNull(0) ? 0 : reader.GetInt32(0),
//            //    ItemName = GetString(reader, 1),
//            //    ItemType = GetString(reader, 2),
//            //    Price = GetDecimal(reader, 3)
//            //});

//            list.Add(new HrmsMenuItem
//            {
//                MenuItemId = reader.IsDBNull(0) ? 0 : reader.GetInt32(0),
//                ItemName = GetString(reader, 1),
//                ItemType = GetString(reader, 2),
//                Price = GetDecimal(reader, 3),
//                MenuDate = GetString(reader, 4),
//                DayOfWeek = GetString(reader, 5),
//                MealName = string.Empty
//            });

//            //list.Add(new HrmsMenuItem
//            //{
//            //    MenuItemId = reader.IsDBNull(0) ? 0 : reader.GetInt32(0),
//            //    ItemName = GetString(reader, 1),
//            //    ItemType = GetString(reader, 2),
//            //    Price = GetDecimal(reader, 3),

//            //    MealName = GetString(reader, 4),
//            //    MenuDate = GetString(reader, 5),
//            //    DayOfWeek = GetString(reader, 6),
//            //});
//        }

//        return list;
//    }

//    private static string GetString(MySqlDataReader reader, int ordinal)
//    {
//        if (reader.IsDBNull(ordinal)) return string.Empty;
//        var v = reader.GetValue(ordinal);
//        return v?.ToString() ?? string.Empty;
//    }

//    private static decimal GetDecimal(MySqlDataReader reader, int ordinal)
//    {
//        if (reader.IsDBNull(ordinal)) return 0m;
//        var v = reader.GetValue(ordinal);
//        return v is decimal d ? d : Convert.ToDecimal(v);
//    }
//}



public class MenuLookupService : IMenuLookupService
{
    private readonly IConfigService _configService;

    public MenuLookupService(IConfigService configService)
    {
        _configService = configService;
    }

    // Implementing the method for fetching menu items by site
    public async Task<IReadOnlyList<HrmsMenuItem>> GetMenuItemsForSiteAsync(int siteIdNumeric, CancellationToken cancellationToken = default)
    {
        // Backwards-compatible: use today's local date.
        return await GetMenuItemsForSiteAndDateAsync(siteIdNumeric, DateTime.Today, "NonManagement", cancellationToken).ConfigureAwait(false);
    }

    // Implementing the method for fetching menu items by site, date, and gradeType
    public async Task<IReadOnlyList<HrmsMenuItem>> GetMenuItemsForSiteAndDateAsync(int siteIdNumeric, DateTime menuDateLocal, string gradeType, CancellationToken cancellationToken = default)
    {
        var connectionString = _configService.GetHrmsLookupConnectionString();
        if (string.IsNullOrWhiteSpace(connectionString))
            return Array.Empty<HrmsMenuItem>();

        const string sql = @"
            SELECT
                mi.id,
                mi.item_name,
                mi.item_type,
                mi.price,
                li.menu_date,
                li.day_of_week
            FROM lunch_menu_week w
            JOIN lunch_menu_item li ON li.lunch_menu_week_id = w.id
            JOIN menu_item mi ON mi.id = li.menu_item_id
            WHERE w.location_site_id = @siteId
              AND @menuDate BETWEEN w.week_start_date AND w.week_end_date
              AND li.menu_date = @menuDate
              AND mi.item_for = @itemFor
            ORDER BY mi.item_name;";

        var itemFor = GetItemForFromGradeType(gradeType);

        await using var conn = new MySqlConnection(connectionString);
        await conn.OpenAsync(cancellationToken).ConfigureAwait(false);
        await using var cmd = new MySqlCommand(sql, conn);
        cmd.Parameters.AddWithValue("@siteId", siteIdNumeric);
        cmd.Parameters.AddWithValue("@menuDate", menuDateLocal.Date);
        cmd.Parameters.AddWithValue("@itemFor", itemFor);

        var list = new List<HrmsMenuItem>();
        await using var reader = await cmd.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false);
        while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
        {
            list.Add(new HrmsMenuItem
            {
                MenuItemId = reader.IsDBNull(0) ? 0 : reader.GetInt32(0),
                ItemName = GetString(reader, 1),
                ItemType = GetString(reader, 2),
                Price = GetDecimal(reader, 3),
                MenuDate = GetString(reader, 4),
                DayOfWeek = GetString(reader, 5),
                MealName = string.Empty
            });
        }

        return list;
    }

    private static string GetItemForFromGradeType(string? gradeType)
    {
        var value = (gradeType ?? string.Empty).Trim().ToLowerInvariant();

        return value switch
        {
            "management" => "MANAGEMENT",
            "nonmanagement" => "NON_MANAGEMENT",
            "non_management" => "NON_MANAGEMENT",
            _ => string.Empty
        };
    }

    private static string GetString(MySqlDataReader reader, int ordinal)
    {
        if (reader.IsDBNull(ordinal)) return string.Empty;
        var v = reader.GetValue(ordinal);
        return v?.ToString() ?? string.Empty;
    }

    private static decimal GetDecimal(MySqlDataReader reader, int ordinal)
    {
        if (reader.IsDBNull(ordinal)) return 0m;
        var v = reader.GetValue(ordinal);
        return v is decimal d ? d : Convert.ToDecimal(v);
    }
}