using System;
using Microsoft.Data.SqlClient;
using System.Threading.Tasks;
using leak_test_project.Models;

namespace leak_test_project.Services
{
    /// <summary>
    /// EOL 검사 데이터를 MSSQL 데이터베이스에 저장하는 서비스 클래스.
    /// </summary>
    public class EolDatabaseService
    {
        private readonly string _connectionString;

        public EolDatabaseService(string connectionString)
        {
            _connectionString = connectionString;
        }

        /// <summary>
        /// EOL 검사 결과를 데이터베이스에 저장합니다. (동일 ID 존재 시 업데이트, 미존재 시 삽입)
        /// </summary>
        /// <param name="inspectData">검사 결과 데이터</param>
        /// <returns>저장 성공 여부 (성공: true, 실패: false)</returns>
        public async Task<bool> SaveEolDataAsync(InspectData inspectData, Housing.Login.StartupLoginWindowResult loginInfo)
        {
            if (inspectData == null) return false;

            // MSSQL MERGE 문을 사용한 UPSERT 처리 (신규 dbo.EOL 스키마 적용)
            const string query = @"
                MERGE INTO [dbo].[EOL] AS Target
                USING (SELECT @IC_SN AS IC_SN) AS Source
                ON (Target.IC_SN = Source.IC_SN)
                WHEN MATCHED THEN
                    UPDATE SET 
                        Target.PCB_Barcode = @PCB_Barcode,
                        Target.Maker = @Maker,
                        Target.Model = @Model,
                        Target.Variant_1 = @Variant_1,
                        Target.Variant_2 = @Variant_2,
                        Target.Operator = @Operator,
                        Target.Production_Date = @Production_Date,
                        Target.Line = @Line,
                        Target.Lot_No = @Lot_No,
                        Target.Jig_No = @Jig_No,
                        Target.Channel = @Channel,
                        Target.Spec_UL = @Spec_UL,
                        Target.Spec_LL = @Spec_LL,
                        Target.Leak_Value = @Leak_Value,
                        Target.Result = @Result
                WHEN NOT MATCHED THEN
                    INSERT (IC_SN, PCB_Barcode, Maker, Model, Variant_1, Variant_2, Operator, Production_Date, Line, Lot_No, Jig_No, Channel, Spec_UL, Spec_LL, Leak_Value, Result)
                    VALUES (@IC_SN, @PCB_Barcode, @Maker, @Model, @Variant_1, @Variant_2, @Operator, @Production_Date, @Line, @Lot_No, @Jig_No, @Channel, @Spec_UL, @Spec_LL, @Leak_Value, @Result);";

            try
            {
                var maker = loginInfo?.Maker ?? string.Empty;
                var model = loginInfo?.Model ?? string.Empty;
                var variant1 = loginInfo?.Variant1 ?? string.Empty;
                var variant2 = loginInfo?.Variant2 ?? string.Empty;
                var operatorId = loginInfo?.Operator ?? string.Empty;
                var lineNo = loginInfo?.LineNo ?? string.Empty;
                var lotNo = loginInfo?.LotNo ?? string.Empty;
                var jigNo = loginInfo?.JigNo ?? string.Empty;
                var builder = new SqlConnectionStringBuilder(_connectionString)
                {
                    ConnectTimeout = 5
                };
                using (var conn = new SqlConnection(builder.ConnectionString))
                {
                    using (var cmd = new SqlCommand(query, conn))
                    {
                        cmd.Parameters.AddWithValue("@IC_SN", string.IsNullOrEmpty(inspectData.IcSn) ? "-" : inspectData.IcSn);
                        cmd.Parameters.AddWithValue("@PCB_Barcode", string.IsNullOrEmpty(inspectData.PcbBarcode) ? "-" : inspectData.PcbBarcode);
                        cmd.Parameters.AddWithValue("@Maker", maker);
                        cmd.Parameters.AddWithValue("@Model", model);
                        cmd.Parameters.AddWithValue("@Variant_1", variant1);
                        cmd.Parameters.AddWithValue("@Variant_2", variant2);
                        cmd.Parameters.AddWithValue("@Operator", operatorId);
                        cmd.Parameters.AddWithValue("@Production_Date", inspectData.ProductionDate ?? DateTime.Now);
                        cmd.Parameters.AddWithValue("@Line", lineNo);
                        cmd.Parameters.AddWithValue("@Lot_No", lotNo);
                        cmd.Parameters.AddWithValue("@Jig_No", jigNo);
                        cmd.Parameters.AddWithValue("@Channel", string.IsNullOrEmpty(inspectData.Channel) ? "N/A" : inspectData.Channel);

                        // Spec_UL, Spec_LL, Leak_Value 형 변환 및 대입
                        decimal specUL = 0;
                        if (decimal.TryParse(inspectData.SpecUL, out var parsedUL)) specUL = parsedUL;
                        cmd.Parameters.AddWithValue("@Spec_UL", specUL);

                        decimal specLL = 0;
                        if (decimal.TryParse(inspectData.SpecLL, out var parsedLL)) specLL = parsedLL;
                        cmd.Parameters.AddWithValue("@Spec_LL", specLL);

                        decimal leakValue = 0;
                        if (decimal.TryParse(inspectData.MeasuredValue, out var parsedValue)) leakValue = parsedValue;
                        cmd.Parameters.AddWithValue("@Leak_Value", leakValue);

                        cmd.Parameters.AddWithValue("@Result", string.IsNullOrEmpty(inspectData.Judgment) ? "NG" : inspectData.Judgment);

                        await conn.OpenAsync();
                        await cmd.ExecuteNonQueryAsync();
                        Console.WriteLine($"[DB SUCCESS] EOL Data saved/updated for IC_SN: {inspectData.ProductId}");
                        return true;
                    }
                }
            }
            catch (Exception ex)
            {
                // 실시간 검사 공정 루프 흐름이 DB 커넥션 예외로 중단되지 않도록 예외 격리 처리
                Console.WriteLine($"[DB ERROR] Failed to upsert EOL Data: {ex.Message}");
                throw;
            }
        }

        /// <summary>
        /// 데이터베이스 연결 상태를 비동기로 확인합니다.
        /// </summary>
        /// <returns>연결 성공 시 true, 실패 시 false</returns>
        public async Task<bool> CheckConnectionAsync()
        {
            try
            {
                var builder = new SqlConnectionStringBuilder(_connectionString)
                {
                    ConnectTimeout = 2
                };
                using (var conn = new SqlConnection(builder.ConnectionString))
                {
                    await conn.OpenAsync();
                    return true;
                }
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine($"[DB Connection Check Error] {ex.Message}");
                return false;
            }
        }

        /// <summary>
        /// dbo.Housing_Assembly 테이블에서 IC_SN을 기준으로 PCB_Barcode를 조회합니다.
        /// </summary>
        public async Task<string> GetPcbBarcodeAsync(string icSn)
        {
            if (string.IsNullOrWhiteSpace(icSn)) return null;

            const string query = "SELECT [PCB_Barcode] FROM [dbo].[Housing_Assembly] WHERE [IC_SN] = @IC_SN";
            var builder = new SqlConnectionStringBuilder(_connectionString)
            {
                ConnectTimeout = 5
            };

            using (var conn = new SqlConnection(builder.ConnectionString))
            {
                using (var cmd = new SqlCommand(query, conn))
                {
                    cmd.Parameters.AddWithValue("@IC_SN", icSn);
                    await conn.OpenAsync();
                    var result = await cmd.ExecuteScalarAsync();
                    if (result != null && result != DBNull.Value)
                    {
                        return result.ToString().Trim();
                    }
                }
            }
            return null; // 해당하는 매칭 데이터 없음
        }
    }
}