// +build go1.8

package mysql

import (
	"database/sql"
	"fmt"
	"reflect"
	"testing"
)

func TestMultiResultSet(t *testing.T) {
	type result struct {
		values  [][]int
		columns []string
	}

	// checkRows is a helper test function to validate rows containing 3 result
	// sets with specific values and columns. The basic query would look like this:
	//
	// SELECT 1 AS col1, 2 AS col2 UNION SELECT 3, 4;
	// SELECT 0 UNION SELECT 1;
	// SELECT 1 AS col1, 2 AS col2, 3 AS col3 UNION SELECT 4, 5, 6;
	//
	// to distinguish test cases the first string argument is put in front of
	// every error or fatal message.
	checkRows := func(desc string, rows *sql.Rows, dbt *DBTest) {
		expected := []result{
			{
				values:  [][]int{{1, 2}, {3, 4}},
				columns: []string{"col1", "col2"},
			},
			{
				values:  [][]int{{1, 2, 3}, {4, 5, 6}},
				columns: []string{"col1", "col2", "col3"},
			},
		}

		var res1 result
		for rows.Next() {
			var res [2]int
			if err := rows.Scan(&res[0], &res[1]); err != nil {
				dbt.Fatal(err)
			}
			res1.values = append(res1.values, res[:])
		}

		cols, err := rows.Columns()
		if err != nil {
			dbt.Fatal(desc, err)
		}
		res1.columns = cols

		if !reflect.DeepEqual(expected[0], res1) {
			dbt.Error(desc, "want =", expected[0], "got =", res1)
		}

		if !rows.NextResultSet() {
			dbt.Fatal(desc, "expected next result set")
		}

		// ignoring one result set

		if !rows.NextResultSet() {
			dbt.Fatal(desc, "expected next result set")
		}

		var res2 result
		cols, err = rows.Columns()
		if err != nil {
			dbt.Fatal(desc, err)
		}
		res2.columns = cols

		for rows.Next() {
			var res [3]int
			if err := rows.Scan(&res[0], &res[1], &res[2]); err != nil {
				dbt.Fatal(desc, err)
			}
			res2.values = append(res2.values, res[:])
		}

		if !reflect.DeepEqual(expected[1], res2) {
			dbt.Error(desc, "want =", expected[1], "got =", res2)
		}

		if rows.NextResultSet() {
			dbt.Error(desc, "unexpected next result set")
		}

		if err := rows.Err(); err != nil {
			dbt.Error(desc, err)
		}
	}

	runTestsWithMultiStatement(t, dsn, func(dbt *DBTest) {
		rows := dbt.mustQuery(`DO 1;
		SELECT 1 AS col1, 2 AS col2 UNION SELECT 3, 4;
		DO 1;
		SELECT 0 UNION SELECT 1;
		SELECT 1 AS col1, 2 AS col2, 3 AS col3 UNION SELECT 4, 5, 6;`)
		defer rows.Close()
		checkRows("query: ", rows, dbt)
	})

	runTestsWithMultiStatement(t, dsn, func(dbt *DBTest) {
		queries := []string{
			`
			DROP PROCEDURE IF EXISTS test_mrss;
			CREATE PROCEDURE test_mrss()
			BEGIN
				DO 1;
				SELECT 1 AS col1, 2 AS col2 UNION SELECT 3, 4;
				DO 1;
				SELECT 0 UNION SELECT 1;
				SELECT 1 AS col1, 2 AS col2, 3 AS col3 UNION SELECT 4, 5, 6;
			END
		`,
			`
			DROP PROCEDURE IF EXISTS test_mrss;
			CREATE PROCEDURE test_mrss()
			BEGIN
				SELECT 1 AS col1, 2 AS col2 UNION SELECT 3, 4;
				SELECT 0 UNION SELECT 1;
				SELECT 1 AS col1, 2 AS col2, 3 AS col3 UNION SELECT 4, 5, 6;
			END
		`,
		}

		defer dbt.mustExec("DROP PROCEDURE IF EXISTS test_mrss")

		for i, query := range queries {
			dbt.mustExec(query)

			stmt, err := dbt.db.Prepare("CALL test_mrss()")
			if err != nil {
				dbt.Fatalf("%v (i=%d)", err, i)
			}
			defer stmt.Close()

			for j := 0; j < 2; j++ {
				rows, err := stmt.Query()
				if err != nil {
					dbt.Fatalf("%v (i=%d) (j=%d)", err, i, j)
				}
				checkRows(fmt.Sprintf("prepared stmt query (i=%d) (j=%d): ", i, j), rows, dbt)
			}
		}
	})
}

func TestMultiResultSetNoSelect(t *testing.T) {
	runTestsWithMultiStatement(t, dsn, func(dbt *DBTest) {
		rows := dbt.mustQuery("DO 1; DO 2;")
		defer rows.Close()

		if rows.Next() {
			dbt.Error("unexpected row")
		}

		if rows.NextResultSet() {
			dbt.Error("unexpected next result set")
		}

		if err := rows.Err(); err != nil {
			dbt.Error("expected nil; got ", err)
		}
	})
}

// tests if rows are set in a proper state if some results were ignored before
// calling rows.NextResultSet.
func TestSkipResults(t *testing.T) {
	runTests(t, dsn, func(dbt *DBTest) {
		rows := dbt.mustQuery("SELECT 1, 2")
		defer rows.Close()

		if !rows.Next() {
			dbt.Error("expected row")
		}

		if rows.NextResultSet() {
			dbt.Error("unexpected next result set")
		}

		if err := rows.Err(); err != nil {
			dbt.Error("expected nil; got ", err)
		}
	})
}