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//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License, version 2.0, as
// published by the Free Software Foundation.
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// which is part of MySQL Connector/NET, is also subject to the
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// See the GNU General Public License, version 2.0, for more details.
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using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Diagnostics;
using Microsoft.EntityFrameworkCore.Query;
using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
using MySql.EntityFrameworkCore.Extensions;
using System;
using System.Collections.Generic;
using System.Reflection;
using static MySql.EntityFrameworkCore.Utils.Statics;

namespace MySql.EntityFrameworkCore.Query.Internal
{
  internal class MySQLDateDiffFunctionsTranslator : IMethodCallTranslator
  {
    private readonly Dictionary<MethodInfo, string> _methodInfoDateDiffMapping
        = new()
        {
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffYear),
              new[] { typeof(DbFunctions), typeof(DateTime), typeof(DateTime) })!,
            "YEAR"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffYear),
              new[] { typeof(DbFunctions), typeof(DateTime?), typeof(DateTime?) })!,
            "YEAR"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffYear),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset), typeof(DateTimeOffset) })!,
            "YEAR"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffYear),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset?), typeof(DateTimeOffset?) })!,
            "YEAR"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMonth),
              new[] { typeof(DbFunctions), typeof(DateTime), typeof(DateTime) })!,
            "MONTH"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMonth),
              new[] { typeof(DbFunctions), typeof(DateTime?), typeof(DateTime?) })!,
            "MONTH"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMonth),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset), typeof(DateTimeOffset) })!,
            "MONTH"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMonth),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset?), typeof(DateTimeOffset?) })!,
            "MONTH"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffDay),
              new[] { typeof(DbFunctions), typeof(DateTime), typeof(DateTime) })!,
            "DAY"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffDay),
              new[] { typeof(DbFunctions), typeof(DateTime?), typeof(DateTime?) })!,
            "DAY"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffDay),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset), typeof(DateTimeOffset) })!,
            "DAY"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffDay),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset?), typeof(DateTimeOffset?) })!,
            "DAY"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffHour),
              new[] { typeof(DbFunctions), typeof(DateTime), typeof(DateTime) })!,
            "HOUR"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffHour),
              new[] { typeof(DbFunctions), typeof(DateTime?), typeof(DateTime?) })!,
            "HOUR"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffHour),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset), typeof(DateTimeOffset) })!,
            "HOUR"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffHour),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset?), typeof(DateTimeOffset?) })!,
            "HOUR"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMinute),
              new[] { typeof(DbFunctions), typeof(DateTime), typeof(DateTime) })!,
            "MINUTE"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMinute),
              new[] { typeof(DbFunctions), typeof(DateTime?), typeof(DateTime?) })!,
            "MINUTE"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMinute),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset), typeof(DateTimeOffset) })!,
            "MINUTE"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMinute),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset?), typeof(DateTimeOffset?) })!,
            "MINUTE"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffSecond),
              new[] { typeof(DbFunctions), typeof(DateTime), typeof(DateTime) })!,
            "SECOND"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffSecond),
              new[] { typeof(DbFunctions), typeof(DateTime?), typeof(DateTime?) })!,
            "SECOND"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffSecond),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset), typeof(DateTimeOffset) })!,
            "SECOND"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffSecond),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset?), typeof(DateTimeOffset?) })!,
            "SECOND"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMicrosecond),
              new[] { typeof(DbFunctions), typeof(DateTime), typeof(DateTime) })!,
            "MICROSECOND"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMicrosecond),
              new[] { typeof(DbFunctions), typeof(DateTime?), typeof(DateTime?) })!,
            "MICROSECOND"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMicrosecond),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset), typeof(DateTimeOffset) })!,
            "MICROSECOND"
          },
          {
            typeof(MySQLDbFunctionsExtensions).GetRuntimeMethod(
              nameof(MySQLDbFunctionsExtensions.DateDiffMicrosecond),
              new[] { typeof(DbFunctions), typeof(DateTimeOffset?), typeof(DateTimeOffset?) })!,
            "MICROSECOND"
          }
        };

    private readonly ISqlExpressionFactory _sqlExpressionFactory;

    public MySQLDateDiffFunctionsTranslator(ISqlExpressionFactory sqlExpressionFactory)
    {
      _sqlExpressionFactory = sqlExpressionFactory;
    }

    public virtual SqlExpression? Translate(SqlExpression? instance, MethodInfo method, IReadOnlyList<SqlExpression> arguments, IDiagnosticsLogger<DbLoggerCategory.Query> logger)
    {
      if (_methodInfoDateDiffMapping.TryGetValue(method, out var datePart))
      {
        var startDate = arguments[1];
        var endDate = arguments[2];
        var typeMapping = ExpressionExtensions.InferTypeMapping(startDate, endDate);

        startDate = _sqlExpressionFactory.ApplyTypeMapping(startDate, typeMapping);
        endDate = _sqlExpressionFactory.ApplyTypeMapping(endDate, typeMapping);

        return _sqlExpressionFactory.Function(
            "TIMESTAMPDIFF",
            new[]
            {
              _sqlExpressionFactory.Fragment(datePart),
              startDate,
              endDate
            },
            nullable: true,
            argumentsPropagateNullability: TrueArrays[3],
            typeof(int));
      }

      return null;
    }
  }
}