package migrator

import (
	_ "embed"
	"testing"

	"github.com/stretchr/testify/require"
)

//go:embed testdata/sqlite_file_migration_statement.sql
var sqliteMigrationStatement string

func TestConvertUniqueKeyToPrimaryKey(t *testing.T) {
	names := []string{
		"drop my_row_id and add primary key with columns path_hash,etag to table file if my_row_id exists (auto-generated mysql column)",
		"drop unique index UQE_file_path_hash_etag from file table if it exists (mysql)",
		"add primary key with columns path_hash,etag to table file if it doesn't exist (mysql)",
		"add primary key with columns path_hash,etag to table file (postgres and sqlite)",
	}
	expectedMigrations := map[string][]ExpectedMigration{
		MySQL: {
			{Id: names[0], SQL: `
			  ALTER TABLE file
			  DROP PRIMARY KEY,
			  DROP COLUMN my_row_id,
			  DROP INDEX UQE_file_path_hash_etag,
			  ADD PRIMARY KEY (` + "`path_hash`" + `,` + "`etag`" + `);`},
			{Id: names[1], SQL: "ALTER TABLE file DROP INDEX UQE_file_path_hash_etag"},
			{Id: names[2], SQL: "ALTER TABLE file ADD PRIMARY KEY (`path_hash`,`etag`)"},
			{Id: names[3], SQL: ""},
		},
		Postgres: {
			{Id: names[0], SQL: ""},
			{Id: names[1], SQL: ""},
			{Id: names[2], SQL: ""},
			{Id: names[3], SQL: `
				DO $$
				BEGIN
					-- Drop the unique constraint if it exists
					DROP INDEX IF EXISTS "UQE_file_path_hash_etag";

					-- Add primary key if it doesn't already exist
					IF NOT EXISTS (SELECT 1 FROM pg_index i WHERE indrelid = 'file'::regclass AND indisprimary) THEN
					ALTER TABLE "file" ADD PRIMARY KEY ("path_hash","etag");
				END IF;
				END $$;`},
		},
		SQLite: {
			{Id: names[0], SQL: ""},
			{Id: names[1], SQL: ""},
			{Id: names[2], SQL: ""},
			{Id: names[3], SQL: sqliteMigrationStatement}, // Embed used here because sqlite statement is full of backquotes.
		},
	}

	for dialectName, migrations := range expectedMigrations {
		t.Run(dialectName, func(t *testing.T) {
			err := CheckExpectedMigrations(dialectName, migrations, func(migrator *Migrator) {
				ConvertUniqueKeyToPrimaryKey(migrator,
					Index{Cols: []string{"path_hash", "etag"}, Type: UniqueIndex}, // Convert this unique key to primary key
					Table{
						Name: "file",
						Columns: []*Column{
							{Name: "path", Type: DB_NVarchar, Length: 1024, Nullable: false},
							{Name: "path_hash", Type: DB_NVarchar, Length: 64, Nullable: false, IsPrimaryKey: true},
							{Name: "parent_folder_path_hash", Type: DB_NVarchar, Length: 64, Nullable: false},
							{Name: "contents", Type: DB_Blob, Nullable: false},
							{Name: "etag", Type: DB_NVarchar, Length: 32, Nullable: false, IsPrimaryKey: true},
						},
						PrimaryKeys: []string{"path_hash", "etag"},
						Indices: []*Index{
							{Cols: []string{"parent_folder_path_hash"}},
						},
					})
			})
			require.NoError(t, err)
		})
	}
}