using Jiaowu.Api.Infrastructure.Persistence;
using Jiaowu.Api.Infrastructure.Exams;
using Jiaowu.Api.Infrastructure.Teaching;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.EntityFrameworkCore.Migrations;
using MySql.Data.MySqlClient;

namespace Jiaowu.Api.Tests;

public sealed class MySqlMigrationTests
{
    private const string LatestMigration =
        "20260726190000_PersonalCalendarSubscription";

    [Fact]
    public void Production_migration_is_discoverable_and_generates_mysql_sql()
    {
        var options = CreateMySqlOptions();
        using var db = new AppDbContext(options);

        Assert.Contains(LatestMigration, db.Database.GetMigrations());

        var script = db.GetService<IMigrator>().GenerateScript(
            fromMigration: "20260725040310_SchedulePublishJobs",
            toMigration: LatestMigration);

        Assert.Contains("CREATE TABLE `GradeItems`", script);
        Assert.Contains("CREATE TABLE `EvaluationSetups`", script);
        Assert.Contains("CREATE TABLE `WarningRules`", script);
        Assert.Contains("ADD `CheckInMethod` int NOT NULL DEFAULT 1", script);
        Assert.Contains("CREATE UNIQUE INDEX `IX_AttendanceSheets_CheckInToken`", script);
        Assert.Contains("ADD COLUMN `WaitlistedAt` datetime(6) NULL", script);
        Assert.Contains(
            "CREATE INDEX `IX_CE_Offering_Status_WaitlistedAt`",
            script);
        Assert.Contains("@waitlisted_column_exists", script);
        Assert.Contains("@waitlist_index_exists", script);
        Assert.DoesNotContain(
            "IX_CourseEnrollments_CourseSelectionOfferingId_Status_WaitlistedAt",
            script);
        Assert.Contains(
            "ADD `MaxCourseCount` int NULL",
            script);
        Assert.Contains(
            "CREATE TABLE `CourseSelectionRoundGrades`",
            script);
        Assert.Contains(
            "CREATE UNIQUE INDEX `IX_CourseSelectionRoundGrades_CourseSelectionRoundId_Grade`",
            script);
        Assert.Contains(
            "ADD `CalendarSubscriptionStamp` varchar(64) NULL",
            script);
        Assert.Contains(
            "ADD `CalendarSubscriptionCreatedAt` datetime(6) NULL",
            script);
        Assert.Contains("SET `ExamDate` = DATE(`StartsAt`)", script);
        Assert.Contains("DEFAULT 1", script);
        Assert.DoesNotContain("0001-01-01", script);
        Assert.DoesNotContain("0000-00-00", script);
    }

    [Fact]
    public void MySql_date_properties_use_datetime_provider_conversion()
    {
        using var db = new AppDbContext(CreateMySqlOptions());

        var dateProperties = db.Model.GetEntityTypes()
            .SelectMany(x => x.GetProperties())
            .Where(x => x.ClrType == typeof(DateOnly) ||
                        x.ClrType == typeof(DateOnly?))
            .ToList();

        Assert.NotEmpty(dateProperties);
        Assert.All(dateProperties, property =>
        {
            Assert.Equal("date", property.GetColumnType());
            Assert.Equal(
                typeof(DateTime),
                property.GetTypeMapping().Converter?.ProviderClrType);
        });
    }

    [Fact]
    public void MySql_guid_collections_use_provider_safe_predicates()
    {
        using var db = new AppDbContext(CreateMySqlOptions());
        var ids = new[]
        {
            Guid.Parse("11111111-1111-1111-1111-111111111111"),
            Guid.Parse("22222222-2222-2222-2222-222222222222")
        };

        var sql = db.Colleges
            .WhereIn(ids, x => x.Id)
            .ToQueryString();

        Assert.Contains(" IN (", sql, StringComparison.OrdinalIgnoreCase);
        Assert.Contains(ids[0].ToString(), sql, StringComparison.OrdinalIgnoreCase);
        Assert.Contains(ids[1].ToString(), sql, StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public void MySql_invigilator_candidate_query_is_translatable_without_uuid_ordering()
    {
        using var db = new AppDbContext(CreateMySqlOptions());
        var excludedTeacherId =
            Guid.Parse("11111111-1111-1111-1111-111111111111");

        var sql = InvigilatorCandidateQuery
            .Create(db, [excludedTeacherId])
            .ToQueryString();

        Assert.Contains("Teachers", sql, StringComparison.OrdinalIgnoreCase);
        Assert.DoesNotContain("UUID(", sql, StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public void MySql_teaching_task_roster_query_is_translatable()
    {
        using var db = new AppDbContext(CreateMySqlOptions());

        var sql = TeachingTaskRosterQuery
            .ForTask(
                db,
                Guid.Parse("11111111-1111-1111-1111-111111111111"))
            .ToQueryString();

        Assert.Contains("TeachingTaskClasses", sql, StringComparison.OrdinalIgnoreCase);
        Assert.Contains("CourseEnrollments", sql, StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public void MySql_index_names_fit_the_server_identifier_limit()
    {
        using var db = new AppDbContext(CreateMySqlOptions());

        var indexNames = db.Model.GetEntityTypes()
            .SelectMany(x => x.GetIndexes())
            .Select(x => x.GetDatabaseName())
            .Where(x => !string.IsNullOrEmpty(x))
            .ToList();

        Assert.NotEmpty(indexNames);
        Assert.All(indexNames, name => Assert.True(
            name!.Length <= 64,
            $"MySQL index name '{name}' has {name.Length} characters."));
    }

    [Fact]
    public void Application_mysql_connections_allow_migration_user_variables()
    {
        var normalized = MySqlConnectionStringPolicy.ForApplication(
            "Server=localhost;Database=jiaowu;User=test;Password=test;");

        var builder = new MySqlConnectionStringBuilder(normalized);

        Assert.True(builder.AllowUserVariables);
    }

    private static DbContextOptions<AppDbContext> CreateMySqlOptions() =>
        new DbContextOptionsBuilder<AppDbContext>()
            .UseMySQL(
                "Server=localhost;Database=jiaowu;User=__test__;Password=__not_used__;")
            .Options;
}