// Copyright (C) 2017 ScyllaDB
// Use of this source code is governed by a ALv2-style
// license that can be found in the LICENSE file.

// +build all integration

package migrate_test

import (
	"context"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/gocql/gocql"
	. "github.com/scylladb/gocqlx/gocqlxtest"
	"github.com/scylladb/gocqlx/migrate"
)

var migrateSchema = `
CREATE TABLE IF NOT EXISTS gocqlx_test.migrate_table (
    testint int,
    testuuid timeuuid,
    PRIMARY KEY(testint, testuuid)
)
`

var insertMigrate = `INSERT INTO gocqlx_test.migrate_table (testint, testuuid) VALUES (%d, now())`

func recreateTables(tb testing.TB, session *gocql.Session) {
	tb.Helper()

	if err := ExecStmt(session, "DROP TABLE IF EXISTS gocqlx_test.gocqlx_migrate"); err != nil {
		tb.Fatal(err)
	}
	if err := ExecStmt(session, migrateSchema); err != nil {
		tb.Fatal(err)
	}
	if err := ExecStmt(session, "TRUNCATE gocqlx_test.migrate_table"); err != nil {
		tb.Fatal(err)
	}
}

func TestMigration(t *testing.T) {
	session := CreateSession(t)
	defer session.Close()
	recreateTables(t, session)

	ctx := context.Background()

	t.Run("init", func(t *testing.T) {
		dir := makeMigrationDir(t, 2)
		defer os.Remove(dir)

		if err := migrate.Migrate(ctx, session, dir); err != nil {
			t.Fatal(err)
		}
		if c := countMigrations(t, session); c != 2 {
			t.Fatal("expected 2 migration got", c)
		}
	})

	t.Run("update", func(t *testing.T) {
		dir := makeMigrationDir(t, 4)
		defer os.Remove(dir)

		if err := migrate.Migrate(ctx, session, dir); err != nil {
			t.Fatal(err)
		}
		if c := countMigrations(t, session); c != 4 {
			t.Fatal("expected 4 migration got", c)
		}
	})

	t.Run("ahead", func(t *testing.T) {
		dir := makeMigrationDir(t, 2)
		defer os.Remove(dir)

		if err := migrate.Migrate(ctx, session, dir); err == nil || !strings.Contains(err.Error(), "ahead") {
			t.Fatal("expected error")
		} else {
			t.Log(err)
		}
	})

	t.Run("tempered with file", func(t *testing.T) {
		dir := makeMigrationDir(t, 4)
		defer os.Remove(dir)

		temperFile(t, dir, "3.cql")

		if err := migrate.Migrate(ctx, session, dir); err == nil || !strings.Contains(err.Error(), "tempered") {
			t.Fatal("expected error")
		} else {
			t.Log(err)
		}
	})
}

func TestMigrationNoSemicolon(t *testing.T) {
	session := CreateSession(t)
	defer session.Close()
	recreateTables(t, session)

	if err := ExecStmt(session, migrateSchema); err != nil {
		t.Fatal(err)
	}

	ctx := context.Background()

	dir := makeMigrationDir(t, 1)
	defer os.Remove(dir)

	f, err := os.OpenFile(filepath.Join(dir, "0.cql"), os.O_WRONLY|os.O_APPEND, 0)
	if err != nil {
		t.Fatal(err)
	}
	fmt.Fprintf(f, insertMigrate, 0) // note no ; at the end
	f.Close()

	if err := migrate.Migrate(ctx, session, dir); err != nil {
		t.Fatal(err)
	}
	if c := countMigrations(t, session); c != 2 {
		t.Fatal("expected 2 migration got", c)
	}
}

func TestMigrationCallback(t *testing.T) {
	var (
		beforeCalled int
		afterCalled  int
	)
	migrate.Callback = func(ctx context.Context, session *gocql.Session, ev migrate.CallbackEvent, name string) error {
		switch ev {
		case migrate.BeforeMigration:
			beforeCalled += 1
		case migrate.AfterMigration:
			afterCalled += 1
		}
		return nil
	}

	defer func() {
		migrate.Callback = nil
	}()

	reset := func() {
		beforeCalled = 0
		afterCalled = 0
	}

	assertCallbacks := func(t *testing.T, b, a int) {
		if beforeCalled != b {
			t.Fatalf("expected %d before calls got %d", b, beforeCalled)
		}
		if afterCalled != b {
			t.Fatalf("expected %d after calls got %d", a, afterCalled)
		}
	}

	session := CreateSession(t)
	defer session.Close()
	recreateTables(t, session)

	if err := ExecStmt(session, migrateSchema); err != nil {
		t.Fatal(err)
	}

	ctx := context.Background()

	t.Run("init", func(t *testing.T) {
		dir := makeMigrationDir(t, 2)
		defer os.Remove(dir)
		reset()

		if err := migrate.Migrate(ctx, session, dir); err != nil {
			t.Fatal(err)
		}
		assertCallbacks(t, 2, 2)
	})

	t.Run("no duplicate calls", func(t *testing.T) {
		dir := makeMigrationDir(t, 4)
		defer os.Remove(dir)
		reset()

		if err := migrate.Migrate(ctx, session, dir); err != nil {
			t.Fatal(err)
		}
		assertCallbacks(t, 2, 2)
	})
}

func makeMigrationDir(tb testing.TB, n int) (dir string) {
	tb.Helper()

	dir, err := ioutil.TempDir("", "gocqlx_migrate")
	if err != nil {
		tb.Fatal(err)
	}

	for i := 0; i < n; i++ {
		path := filepath.Join(dir, fmt.Sprint(i, ".cql"))
		cql := []byte(fmt.Sprintf(insertMigrate, i) + ";")
		if err := ioutil.WriteFile(path, cql, os.ModePerm); err != nil {
			os.Remove(dir)
			tb.Fatal(err)
		}
	}

	return dir
}

func countMigrations(tb testing.TB, session *gocql.Session) int {
	tb.Helper()

	q := session.Query("SELECT COUNT(*) FROM gocqlx_test.migrate_table")
	defer q.Release()

	var v int
	if err := q.Scan(&v); err != nil {
		tb.Fatal(err)
	}
	return v
}

func temperFile(tb testing.TB, dir, name string) {
	tb.Helper()

	if err := ioutil.WriteFile(filepath.Join(dir, name), []byte("SELECT * FROM bla;"), os.ModePerm); err != nil {
		tb.Fatal(err)
	}
}