package store

import (
	"context"
	"errors"
	"fmt"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"golang.org/x/exp/rand"

	"github.com/grafana/grafana/pkg/infra/db"
	"github.com/grafana/grafana/pkg/services/ngalert/models"
	"github.com/grafana/grafana/pkg/setting"
	"github.com/grafana/grafana/pkg/util"
)

func TestIntegrationUpdateAlertRules(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping integration test")
	}
	sqlStore := db.InitTestDB(t)
	store := &DBstore{
		SQLStore: sqlStore,
		Cfg: setting.UnifiedAlertingSettings{
			BaseInterval: time.Duration(rand.Int63n(100)) * time.Second,
		},
	}

	t.Run("should increase version", func(t *testing.T) {
		rule := createRule(t, store)
		newRule := models.CopyRule(rule)
		newRule.Title = util.GenerateShortUID()
		err := store.UpdateAlertRules(context.Background(), []models.UpdateRule{{
			Existing: rule,
			New:      *newRule,
		},
		})
		require.NoError(t, err)

		dbrule := &models.AlertRule{}
		err = sqlStore.WithDbSession(context.Background(), func(sess *db.Session) error {
			exist, err := sess.Table(models.AlertRule{}).ID(rule.ID).Get(dbrule)
			require.Truef(t, exist, fmt.Sprintf("rule with ID %d does not exist", rule.ID))
			return err
		})

		require.NoError(t, err)
		require.Equal(t, rule.Version+1, dbrule.Version)
	})

	t.Run("should fail due to optimistic locking if version does not match", func(t *testing.T) {
		rule := createRule(t, store)
		rule.Version-- // simulate version discrepancy

		newRule := models.CopyRule(rule)
		newRule.Title = util.GenerateShortUID()

		err := store.UpdateAlertRules(context.Background(), []models.UpdateRule{{
			Existing: rule,
			New:      *newRule,
		},
		})

		require.ErrorIs(t, err, ErrOptimisticLock)
	})
}

func withIntervalMatching(baseInterval time.Duration) func(*models.AlertRule) {
	return func(rule *models.AlertRule) {
		rule.IntervalSeconds = int64(baseInterval.Seconds()) * rand.Int63n(10)
		rule.For = time.Duration(rule.IntervalSeconds*rand.Int63n(9)+1) * time.Second
	}
}

func TestIntegration_getFilterByOrgsString(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping integration test")
	}
	testCases := []struct {
		testName       string
		orgs           map[int64]struct{}
		expectedFilter string
		expectedArgs   []interface{}
	}{
		{
			testName:       "should return empty string if map is empty",
			orgs:           map[int64]struct{}{},
			expectedFilter: "",
			expectedArgs:   nil,
		},
		{
			testName:       "should return empty string if map is nil",
			orgs:           nil,
			expectedFilter: "",
			expectedArgs:   nil,
		},
		{
			testName: "should return correct filter if single element",
			orgs: map[int64]struct{}{
				1: {},
			},
			expectedFilter: "org_id NOT IN(?)",
			expectedArgs:   []interface{}{int64(1)},
		},
		{
			testName: "should return correct filter if many elements",
			orgs: map[int64]struct{}{
				1: {},
				2: {},
				3: {},
			},
			expectedFilter: "org_id NOT IN(?,?,?)",
			expectedArgs:   []interface{}{int64(1), int64(2), int64(3)},
		},
	}
	for _, testCase := range testCases {
		t.Run(testCase.testName, func(t *testing.T) {
			store := &DBstore{
				Cfg: setting.UnifiedAlertingSettings{
					DisabledOrgs: testCase.orgs,
				},
			}
			filter, args := store.getFilterByOrgsString()
			assert.Equal(t, testCase.expectedFilter, filter)
			assert.ElementsMatch(t, testCase.expectedArgs, args)
		})
	}
}

func TestIntegration_CountAlertRules(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping integration test")
	}

	sqlStore := db.InitTestDB(t)
	store := &DBstore{SQLStore: sqlStore}
	rule := createRule(t, store)

	tests := map[string]struct {
		query     *models.CountAlertRulesQuery
		expected  int64
		expectErr bool
	}{
		"basic success": {
			&models.CountAlertRulesQuery{
				NamespaceUID: rule.NamespaceUID,
				OrgID:        rule.OrgID,
			},
			1,
			false,
		},
		"successfully returning no results": {
			&models.CountAlertRulesQuery{
				NamespaceUID: "probably not a uid we'd generate",
				OrgID:        rule.OrgID,
			},
			0,
			false,
		},
	}

	for name, test := range tests {
		t.Run(name, func(t *testing.T) {
			count, err := store.CountAlertRulesInFolder(context.Background(), test.query)
			if test.expectErr {
				require.Error(t, err)
			} else {
				require.NoError(t, err)
				require.Equal(t, test.expected, count)
			}
		})
	}
}

func createRule(t *testing.T, store *DBstore) *models.AlertRule {
	rule := models.AlertRuleGen(withIntervalMatching(store.Cfg.BaseInterval))()
	err := store.SQLStore.WithDbSession(context.Background(), func(sess *db.Session) error {
		_, err := sess.Table(models.AlertRule{}).InsertOne(rule)
		if err != nil {
			return err
		}
		dbRule := &models.AlertRule{}
		exist, err := sess.Table(models.AlertRule{}).ID(rule.ID).Get(dbRule)
		if err != nil {
			return err
		}
		if !exist {
			return errors.New("cannot read inserted record")
		}
		rule = dbRule
		return nil
	})
	require.NoError(t, err)
	return rule
}