// Copyright 2021 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package database

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

	"github.com/google/go-cmp/cmp"
	"github.com/jackc/pgx/v4"
	"github.com/jackc/pgx/v4/stdlib"
)

type copyRow struct {
	Key   int
	Value string
}

func TestCopyInsert(t *testing.T) {
	pgxOnly(t)
	ctx := context.Background()
	for _, stmt := range []string{
		`DROP TABLE IF EXISTS test_streaming_insert`,
		`CREATE TABLE test_streaming_insert (key INTEGER PRIMARY KEY, value TEXT)`,
		`INSERT INTO test_streaming_insert (key, value) VALUES (1, 'foo'), (2, 'bar')`,
	} {
		if _, err := testDB.Exec(ctx, stmt); err != nil {
			t.Fatal(err)
		}
	}
	rows := [][]interface{}{
		{3, "baz"},
		{4, "moo"},
	}
	err := testDB.Transact(ctx, sql.LevelDefault, func(tx *DB) error {
		return tx.CopyInsert(ctx, "test_streaming_insert", []string{"key", "value"}, pgx.CopyFromRows(rows), "")
	})
	if err != nil {
		t.Fatal(err)
	}

	compareRows(ctx, t, "test_streaming_insert", []copyRow{
		{1, "foo"},
		{2, "bar"},
		{3, "baz"},
		{4, "moo"},
	})
}

func TestCopyUpsert(t *testing.T) {
	pgxOnly(t)
	ctx := context.Background()
	for _, stmt := range []string{
		`DROP TABLE IF EXISTS test_streaming_upsert`,
		`CREATE TABLE test_streaming_upsert (key INTEGER PRIMARY KEY, value TEXT)`,
		`INSERT INTO test_streaming_upsert (key, value) VALUES (1, 'foo'), (2, 'bar')`,
	} {
		if _, err := testDB.Exec(ctx, stmt); err != nil {
			t.Fatal(err)
		}
	}
	rows := [][]interface{}{
		{3, "baz"}, // new row
		{1, "moo"}, // replace "foo" with "moo"
	}
	err := testDB.Transact(ctx, sql.LevelDefault, func(tx *DB) error {
		return tx.CopyUpsert(ctx, "test_streaming_upsert", []string{"key", "value"}, pgx.CopyFromRows(rows), []string{"key"}, "")
	})
	if err != nil {
		t.Fatal(err)
	}
	compareRows(ctx, t, "test_streaming_upsert", []copyRow{
		{1, "moo"},
		{2, "bar"},
		{3, "baz"},
	})
}

func compareRows(ctx context.Context, t *testing.T, table string, wantRows []copyRow) {
	t.Helper()
	q := fmt.Sprintf(`SELECT * FROM %s ORDER BY key`, table)
	gotRows, err := CollectStructs[copyRow](ctx, testDB, q)
	if err != nil {
		t.Fatal(err)
	}
	if !cmp.Equal(gotRows, wantRows) {
		t.Errorf("got %v, want %v", gotRows, wantRows)
	}
}

func TestCopyUpsertGeneratedColumn(t *testing.T) {
	pgxOnly(t)
	ctx := context.Background()
	stmt := `
		DROP TABLE IF EXISTS test_copy_gen;
		CREATE TABLE test_copy_gen (id bigint PRIMARY KEY GENERATED ALWAYS AS IDENTITY, key INT, value TEXT, UNIQUE (key));
		INSERT INTO test_copy_gen (key, value) VALUES (11, 'foo'), (12, 'bar')`
	if _, err := testDB.Exec(ctx, stmt); err != nil {
		t.Fatal(err)
	}

	rows := [][]interface{}{
		{13, "baz"}, // new row
		{11, "moo"}, // replace "foo" with "moo"
	}
	err := testDB.Transact(ctx, sql.LevelDefault, func(tx *DB) error {
		return tx.CopyUpsert(ctx, "test_copy_gen", []string{"key", "value"}, pgx.CopyFromRows(rows), []string{"key"}, "id")
	})
	if err != nil {
		t.Fatal(err)
	}

	type row struct {
		ID    int64
		Key   int
		Value string
	}
	wantRows := []row{
		{1, 11, "moo"},
		{2, 12, "bar"},
		{3, 13, "baz"},
	}
	gotRows, err := CollectStructs[row](ctx, testDB, `SELECT * FROM test_copy_gen ORDER BY ID`)
	if err != nil {
		t.Fatal(err)
	}
	if !cmp.Equal(gotRows, wantRows) {
		t.Errorf("got %v, want %v", gotRows, wantRows)
	}
}

func pgxOnly(t *testing.T) {
	conn, err := testDB.db.Conn(context.Background())
	if err != nil {
		t.Fatal(err)
	}
	conn.Raw(func(c interface{}) error {
		if _, ok := c.(*stdlib.Conn); !ok {
			t.Skip("skipping; DB driver not pgx")
		}
		return nil
	})
}