package database_test

import (
	"context"
	"database/sql"
	"testing"

	_ "github.com/mattn/go-sqlite3"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"sneak.berlin/go/upaas/internal/database"
)

func TestParseMigrationVersion(t *testing.T) {
	t.Parallel()

	tests := []struct {
		filename    string
		wantVersion int
		wantErr     bool
	}{
		{filename: "000_migration.sql", wantVersion: 0},
		{filename: "001_initial.sql", wantVersion: 1},
		{filename: "002_remove_container_id.sql", wantVersion: 2},
		{filename: "007_add_resource_limits.sql", wantVersion: 7},
		{filename: "100_large_version.sql", wantVersion: 100},
		{filename: ".sql", wantErr: true},
		{filename: "_foo.sql", wantErr: true},
		{filename: "abc_foo.sql", wantErr: true},
		{filename: "1a2_bad.sql", wantErr: true},
	}

	for _, tt := range tests {
		t.Run(tt.filename, func(t *testing.T) {
			t.Parallel()

			version, err := database.ParseMigrationVersion(tt.filename)
			if tt.wantErr {
				assert.Error(t, err)

				return
			}

			require.NoError(t, err)
			assert.Equal(t, tt.wantVersion, version)
		})
	}
}

func TestApplyMigrationsFreshDatabase(t *testing.T) {
	t.Parallel()

	db, err := sql.Open("sqlite3", ":memory:?_foreign_keys=on")
	require.NoError(t, err)

	defer func() { _ = db.Close() }()

	ctx := context.Background()

	err = database.ApplyMigrations(ctx, db, nil)
	require.NoError(t, err)

	// Verify schema_migrations table exists with INTEGER version column.
	var version int

	err = db.QueryRowContext(ctx,
		"SELECT version FROM schema_migrations WHERE version = 0",
	).Scan(&version)
	require.NoError(t, err)
	assert.Equal(t, 0, version)

	// Verify that all migrations were recorded.
	var count int

	err = db.QueryRowContext(ctx,
		"SELECT COUNT(*) FROM schema_migrations",
	).Scan(&count)
	require.NoError(t, err)
	// 000 bootstrap + 001 through 007 = 8 entries.
	assert.Equal(t, 8, count)

	// Verify application tables were created by the migrations.
	var tableCount int

	err = db.QueryRowContext(ctx,
		"SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name='users'",
	).Scan(&tableCount)
	require.NoError(t, err)
	assert.Equal(t, 1, tableCount)
}

func TestApplyMigrationsIdempotent(t *testing.T) {
	t.Parallel()

	db, err := sql.Open("sqlite3", ":memory:?_foreign_keys=on")
	require.NoError(t, err)

	defer func() { _ = db.Close() }()

	ctx := context.Background()

	// Apply twice — second run should be a no-op.
	err = database.ApplyMigrations(ctx, db, nil)
	require.NoError(t, err)

	err = database.ApplyMigrations(ctx, db, nil)
	require.NoError(t, err)

	var count int

	err = db.QueryRowContext(ctx,
		"SELECT COUNT(*) FROM schema_migrations",
	).Scan(&count)
	require.NoError(t, err)
	assert.Equal(t, 8, count)
}