// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package actions

import (
	"context"
	"fmt"
	"time"

	"gitea.dev/models/db"
	repo_model "gitea.dev/models/repo"
	user_model "gitea.dev/models/user"
	"gitea.dev/modules/git"
	"gitea.dev/modules/timeutil"
	"gitea.dev/modules/util"
	webhook_module "gitea.dev/modules/webhook"
)

// ActionSchedule represents a schedule of a workflow file
type ActionSchedule struct {
	ID            int64
	Title         string
	Specs         []string
	RepoID        int64                  `xorm:"index"`
	Repo          *repo_model.Repository `xorm:"-"`
	OwnerID       int64                  `xorm:"index"`
	WorkflowID    string
	TriggerUserID int64
	TriggerUser   *user_model.User `xorm:"-"`
	Ref           string
	CommitSHA     string
	Event         webhook_module.HookEventType
	EventPayload  string             `xorm:"LONGTEXT"`
	Content       []byte             `xorm:"LONGBLOB"`
	Created       timeutil.TimeStamp `xorm:"created"`
	Updated       timeutil.TimeStamp `xorm:"updated"`
}

func init() {
	db.RegisterModel(new(ActionSchedule))
}

type scheduleSpecKey struct {
	scheduleID int64
	spec       string
}

// ReplaceScheduleTasksByRepo updates schedules in place and keeps the specs of unchanged crons, so re-registering cannot skip a due occurrence.
func ReplaceScheduleTasksByRepo(ctx context.Context, repoID int64, rows []*ActionSchedule) error {
	return db.WithTx(ctx, func(ctx context.Context) error {
		var oldSchedules []*ActionSchedule
		if err := db.GetEngine(ctx).Cols("id", "workflow_id").Where("repo_id = ?", repoID).Find(&oldSchedules); err != nil {
			return err
		}
		var oldSpecs []*ActionScheduleSpec
		if err := db.GetEngine(ctx).Cols("id", "schedule_id", "spec").Where("repo_id = ?", repoID).Find(&oldSpecs); err != nil {
			return err
		}
		scheduleIDs := make(map[string]int64, len(oldSchedules))
		for _, schedule := range oldSchedules {
			scheduleIDs[schedule.WorkflowID] = schedule.ID
		}
		specIDs := make(map[scheduleSpecKey]int64, len(oldSpecs))
		for _, spec := range oldSpecs {
			specIDs[scheduleSpecKey{spec.ScheduleID, spec.Spec}] = spec.ID
		}

		var keptScheduleIDs, keptSpecIDs []int64

		// Loop through each schedule row
		for _, row := range rows {
			row.Title = util.EllipsisDisplayString(row.Title, 255)
			if id, ok := scheduleIDs[row.WorkflowID]; ok {
				row.ID = id
				if _, err := db.GetEngine(ctx).ID(id).AllCols().Update(row); err != nil {
					return err
				}
			} else if err := db.Insert(ctx, row); err != nil {
				return err
			}
			keptScheduleIDs = append(keptScheduleIDs, row.ID)

			// Loop through each schedule spec and create a new spec row
			now := time.Now()

			for _, spec := range row.Specs {
				key := scheduleSpecKey{row.ID, spec}
				if id, ok := specIDs[key]; ok {
					delete(specIDs, key)
					keptSpecIDs = append(keptSpecIDs, id)
					continue
				}

				specRow := &ActionScheduleSpec{
					RepoID:     row.RepoID,
					ScheduleID: row.ID,
					Spec:       spec,
				}
				schedule, err := specRow.Parse()
				if err != nil {
					continue
				}

				next := schedule.Next(now)
				if next.IsZero() {
					continue // the spec parses but can never occur, like "0 0 30 2 *"
				}
				specRow.Next = timeutil.TimeStamp(next.Unix())

				// Insert the new schedule spec row
				if err = db.Insert(ctx, specRow); err != nil {
					return err
				}
				keptSpecIDs = append(keptSpecIDs, specRow.ID)
			}
		}

		// an empty NotIn matches every row
		if _, err := db.GetEngine(ctx).Where("repo_id = ?", repoID).NotIn("id", keptScheduleIDs).Delete(&ActionSchedule{}); err != nil {
			return err
		}
		_, err := db.GetEngine(ctx).Where("repo_id = ?", repoID).NotIn("id", keptSpecIDs).Delete(&ActionScheduleSpec{})
		return err
	})
}

func DeleteScheduleTaskByRepo(ctx context.Context, id int64) error {
	return db.WithTx(ctx, func(ctx context.Context) error {
		if _, err := db.GetEngine(ctx).Delete(&ActionSchedule{RepoID: id}); err != nil {
			return err
		}

		if _, err := db.GetEngine(ctx).Delete(&ActionScheduleSpec{RepoID: id}); err != nil {
			return err
		}

		return nil
	})
}

func CleanRepoScheduleTasks(ctx context.Context, repo *repo_model.Repository) ([]*ActionRunJob, error) {
	// If actions disabled when there is schedule task, this will remove the outdated schedule tasks
	// There is no other place we can do this because the app.ini will be changed manually
	if err := DeleteScheduleTaskByRepo(ctx, repo.ID); err != nil {
		return nil, fmt.Errorf("CleanRepoScheduleTasks: %w", err)
	}
	// cancel running cron jobs of this repository and delete old schedules
	jobs, err := CancelPreviousJobs(
		ctx,
		repo.ID,
		git.RefNameFromBranch(repo.DefaultBranch).String(),
		"",
		webhook_module.HookEventSchedule,
	)
	if err != nil {
		return jobs, fmt.Errorf("CleanRepoScheduleTasks: %w", err)
	}
	return jobs, nil
}