using System;
using System.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>
        public async Task SaveEolDataAsync(InspectData inspectData)
        {
            if (inspectData == null) return;

            // MSSQL MERGE 문을 사용한 UPSERT 처리
            const string query = @"
                MERGE INTO [dbo].[EOL] AS Target
                USING (SELECT @ID AS ID) AS Source
                ON (Target.ID = Source.ID)
                WHEN MATCHED THEN
                    UPDATE SET 
                        Target.Channel = @Channel,
                        Target.SpecUL = @SpecUL,
                        Target.SpecLL = @SpecLL,
                        Target.LeakValue = @LeakValue,
                        Target.Result = @Result,
                        Target.InspectDate = @InspectDate,
                        Target.InspectTime = @InspectTime
                WHEN NOT MATCHED THEN
                    INSERT ([ID], [Channel], [SpecUL], [SpecLL], [LeakValue], [Result], [InspectDate], [InspectTime])
                    VALUES (@ID, @Channel, @SpecUL, @SpecLL, @LeakValue, @Result, @InspectDate, @InspectTime);";

            try
            {
                using (var conn = new SqlConnection(_connectionString))
                {
                    using (var cmd = new SqlCommand(query, conn))
                    {
                        cmd.Parameters.AddWithValue("@ID", string.IsNullOrEmpty(inspectData.ProductId) ? "-" : inspectData.ProductId);
                        cmd.Parameters.AddWithValue("@Channel", string.IsNullOrEmpty(inspectData.Channel) ? "N/A" : inspectData.Channel);
                        cmd.Parameters.AddWithValue("@SpecUL", string.IsNullOrEmpty(inspectData.SpecUL) ? "0.00" : inspectData.SpecUL);
                        cmd.Parameters.AddWithValue("@SpecLL", string.IsNullOrEmpty(inspectData.SpecLL) ? "0.00" : inspectData.SpecLL);
                        cmd.Parameters.AddWithValue("@LeakValue", string.IsNullOrEmpty(inspectData.MeasuredValue) ? "0.0000" : inspectData.MeasuredValue);
                        cmd.Parameters.AddWithValue("@Result", string.IsNullOrEmpty(inspectData.Judgment) ? "NG" : inspectData.Judgment);
                        cmd.Parameters.AddWithValue("@InspectDate", string.IsNullOrEmpty(inspectData.InspectDate) ? DateTime.Now.ToString("yyyy-MM-dd") : inspectData.InspectDate);
                        cmd.Parameters.AddWithValue("@InspectTime", string.IsNullOrEmpty(inspectData.InspectTime) ? DateTime.Now.ToString("HH:mm:ss") : inspectData.InspectTime);

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

        /// <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
            {
                return false;
            }
        }
    }
}