using HrynCo.NotificationService.DAL.Abstract.Repositories;
using HrynCo.NotificationService.DAL.EF;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.EntityFrameworkCore.Migrations;
using Microsoft.Extensions.DependencyInjection;
using Npgsql;

namespace HrynCo.NotificationService.Web.IntegrationTests;

public sealed class EmailTemplateMigrationTests(TemplateDatabaseFixture fixture) : IClassFixture<TemplateDatabaseFixture>
{
    [Fact]
    public async Task EquivalentContracts_PreserveLanguageIdsContentAndSharedVariables_AndRerunSafely()
    {
        var connection = await fixture.CreateDatabaseAsync(legacy: true);
        var en = await TemplateDatabaseFixture.InsertLegacyAsync(connection, "en", """[{"name":"Name","required":true},{"name":"Link","required":false}]""");
        var uk = await TemplateDatabaseFixture.InsertLegacyAsync(connection, "UK", """[{"required":false,"name":"Link"},{"required":true,"name":"Name"}]""");
        await MigrateAsync(connection);
        await MigrateAsync(connection);
        using var services = new ServiceCollection().AddNotificationDataAccess(connection).BuildServiceProvider();
        using var scope = services.CreateScope();
        var repository = scope.ServiceProvider.GetRequiredService<IEmailTemplateRepository>();
        var templates = await repository.GetAllAsync("TestService", "Welcome");
        Assert.Equal(2, templates.Count);
        Assert.Contains(templates, t => t.Id == en && t.Subject == "Subject en" && t.HtmlBody == "<p>{{Name}}</p>");
        Assert.Contains(templates, t => t.Id == uk && t.LanguageCode == "UK" && t.Subject == "Subject UK");
        Assert.All(templates, t => Assert.Equal(2, t.Variables.Count));
        await using var db = TemplateDatabaseFixture.CreateContext(connection);
        await db.GetService<IMigrator>().MigrateAsync(TemplateDatabaseFixture.LegacyMigration);
        await db.Database.MigrateAsync();
        Assert.Equal(en, (await repository.GetAsync("TestService", "Welcome", "en"))!.Id);
    }

    [Theory]
    [InlineData("[{\"name\":\"Other\",\"required\":true}]", "Conflicting shared variables")]
    [InlineData("{}", "Invalid template identity or variables array")]
    [InlineData("[null]", "Invalid variables shape")]
    [InlineData("[{\"name\":\"Name\",\"required\":\"yes\"}]", "Invalid variables shape")]
    [InlineData("[{\"name\":\"Name\",\"required\":true},{\"name\":\"Name\",\"required\":true}]", "Duplicate variable names")]
    public async Task InvalidLegacyData_StopsWithoutChangingSource_ThenCanRecover(string variables, string diagnostic)
    {
        var connection = await fixture.CreateDatabaseAsync(legacy: true);
        await TemplateDatabaseFixture.InsertLegacyAsync(connection, "en", """[{"name":"Name","required":true}]""");
        await TemplateDatabaseFixture.InsertLegacyAsync(connection, "uk", variables);
        var error = await Assert.ThrowsAsync<PostgresException>(() => MigrateAsync(connection));
        Assert.Contains(diagnostic, error.MessageText);
        Assert.Contains("TestService", error.MessageText);
        Assert.DoesNotContain("Hello", error.MessageText);
        await TemplateDatabaseFixture.ExecuteAsync(connection, """
            DO $$ BEGIN
                IF to_regclass('public.services') IS NOT NULL OR (SELECT count(*) FROM email_templates) <> 2 THEN
                    RAISE EXCEPTION 'Migration partially changed source';
                END IF;
            END $$;
            UPDATE email_templates SET variables = '[{"name":"Name","required":true}]'::jsonb;
            """);
        await MigrateAsync(connection);
    }

    [Fact]
    public async Task ExactLanguageCodes_RemainDistinctAfterMigration()
    {
        var connection = await fixture.CreateDatabaseAsync(legacy: true);
        await TemplateDatabaseFixture.InsertLegacyAsync(connection, "ru", "[]");
        await TemplateDatabaseFixture.InsertLegacyAsync(connection, "ru-RU", "[]");
        await TemplateDatabaseFixture.InsertLegacyAsync(connection, "EN", "[]");
        await TemplateDatabaseFixture.InsertLegacyAsync(connection, "en", "[]");
        await MigrateAsync(connection);
        await TemplateDatabaseFixture.ExecuteAsync(connection, """
            DO $$ BEGIN
                IF (SELECT count(*) FROM service_languages) <> 4
                   OR NOT EXISTS (SELECT 1 FROM service_languages WHERE code = 'ru-RU')
                   OR NOT EXISTS (SELECT 1 FROM service_languages WHERE code = 'EN') THEN
                    RAISE EXCEPTION 'Migration changed exact language codes';
                END IF;
            END $$;
            """);
    }

    [Fact]
    public async Task InterruptedConversion_RollsBackAndCanBeRetried()
    {
        var connectionString = await fixture.CreateDatabaseAsync(legacy: true);
        await TemplateDatabaseFixture.InsertLegacyAsync(connectionString, "en", "[]");
        await using var db = TemplateDatabaseFixture.CreateContext(connectionString);
        var script = db.GetService<IMigrator>().GenerateScript(TemplateDatabaseFixture.LegacyMigration, options: MigrationsSqlGenerationOptions.NoTransactions);
        script = script.Replace("ALTER TABLE email_templates DROP COLUMN", "PERFORM pg_sleep(2); ALTER TABLE email_templates DROP COLUMN");
        await using (var connection = new NpgsqlConnection(connectionString))
        {
            await connection.OpenAsync();
            await using var transaction = await connection.BeginTransactionAsync();
            await using var command = new NpgsqlCommand("SET LOCAL statement_timeout = '500ms'; " + script, connection, transaction);
            var error = await Assert.ThrowsAsync<PostgresException>(() => command.ExecuteNonQueryAsync());
            Assert.Equal("57014", error.SqlState);
            await transaction.RollbackAsync();
        }
        await MigrateAsync(connectionString);
    }

    private static async Task MigrateAsync(string connectionString)
    {
        await using var db = TemplateDatabaseFixture.CreateContext(connectionString);
        await db.Database.MigrateAsync();
    }
}