// schedules 演示持久化周期任务：创建、恢复、Worker 执行、触发历史和暂停。
package main

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"os"
	"time"

	orbit "git.yuntuo.hk/k2safe/orbit/sdk/go"
)

func main() {
	if err := run(); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}
func run() error {
	token, queue := os.Getenv("ORBIT_TOKEN"), os.Getenv("ORBIT_QUEUE_ID")
	if path := os.Getenv("ORBIT_CREDENTIALS_FILE"); path != "" {
		raw, err := os.ReadFile(path)
		if err != nil {
			return fmt.Errorf("read private credentials: %w", err)
		}
		var credentials struct {
			Token   string `json:"token"`
			QueueID string `json:"queue_id"`
		}
		if json.Unmarshal(raw, &credentials) != nil {
			return errors.New("invalid credentials file")
		}
		if token == "" {
			token = credentials.Token
		}
		if queue == "" {
			queue = credentials.QueueID
		}
	}
	client, err := orbit.NewClient(os.Getenv("ORBIT_URL"), orbit.Options{Token: token})
	if err != nil {
		return err
	}

	operation, err := orbit.NewWorkerMessageID()
	if err != nil {
		return err
	}
	handler := "object.snapshot." + operation
	ctx, cancel := context.WithTimeout(context.Background(), 25*time.Second)
	defer cancel()
	worker, err := orbit.NewWorker(client, orbit.WorkerOptions{QueueID: queue, Capacity: 1, ShutdownTimeout: 5 * time.Second, Handlers: []orbit.WorkerHandler{{Capability: orbit.WorkerCapability{Handler: handler, HandlerVersion: "v1", PayloadVersion: "v1"}, Handle: func(ctx context.Context, e orbit.WorkerExecution) (json.RawMessage, error) {
		if err := ctx.Err(); err != nil {
			return nil, err
		}
		// 实际副作用应按 Task.ID 或业务操作键去重；此示例只返回输入快照。
		return e.Task.Payload, nil
	}}}})
	if err != nil {
		return err
	}
	start := time.Now().UTC().Truncate(time.Microsecond).Add(1500 * time.Millisecond)
	end := start.Add(10 * time.Second)
	created, err := client.CreateSchedule(ctx, "create-"+operation, orbit.CreateScheduleRequest{Name: handler, Paused: true, Definition: orbit.ScheduleDefinition{
		Rule:   orbit.ScheduleRule{Kind: "FIXED_RATE", Timezone: "UTC", StartAt: start, EndAt: &end, IntervalMS: 1000},
		Policy: orbit.SchedulePolicy{Misfire: "COALESCE", Overlap: "SERIAL", CatchupLimit: 2, CatchupWindowMS: 30000, GraceMS: 1000},
		Task:   orbit.SubmitTaskRequest{QueueID: queue, Handler: handler, HandlerVersion: "v1", PayloadVersion: "v1", Payload: json.RawMessage(`{"source_ref":"objects/sample","sequence":9007199254740993}`)},
	}})
	if err != nil {
		return err
	}
	if _, err := client.ResumeSchedule(ctx, created.Schedule.ID, "resume-"+operation, orbit.ControlScheduleRequest{ExpectedRevision: created.Schedule.Revision, Reason: "start bounded example"}); err != nil {
		return err
	}
	workerCtx, stop := context.WithCancel(ctx)
	done := make(chan error, 1)
	go func() { done <- worker.Run(workerCtx) }()
	waited := false
	defer func() {
		stop()
		if !waited {
			<-done
		}
	}()
	completed := map[string]bool{}
	for len(completed) < 2 {
		page, err := client.ListScheduleOccurrences(ctx, created.Schedule.ID, orbit.SchedulePageRequest{})
		if err != nil {
			return err
		}
		for _, item := range page.Items {
			if item.TaskID == nil || completed[*item.TaskID] {
				continue
			}
			task, err := client.GetTask(ctx, *item.TaskID)
			if err != nil {
				return err
			}
			if task.State == orbit.TaskSucceeded {
				origin, err := client.GetTaskSource(ctx, task.ID)
				if err != nil {
					return err
				}
				if origin.Kind != "SCHEDULE" || origin.Schedule == nil || origin.Schedule.ScheduleID != created.Schedule.ID || origin.Schedule.OccurrenceID != item.ID || origin.Schedule.ScheduleVersion != item.ScheduleVersion {
					return errors.New("task source did not match frozen occurrence")
				}
				fmt.Printf("source_kind=%s fixed_version=%d\n", origin.Kind, origin.Schedule.ScheduleVersion)
				completed[task.ID] = true
				fmt.Printf("schedule=%s occurrence=%s task=%s version=%d state=%s\n", created.Schedule.ID, item.ID, task.ID, item.ScheduleVersion, task.State)
			}
			if task.State == orbit.TaskFailed || task.State == orbit.TaskNeedsReview {
				return fmt.Errorf("scheduled task requires attention: %s", task.State)
			}
		}
		if len(completed) >= 2 {
			break
		}
		select {
		case err := <-done:
			waited = true
			return fmt.Errorf("Worker stopped before completion: %v", err)
		case <-ctx.Done():
			return ctx.Err()
		case <-time.After(100 * time.Millisecond):
		}
	}
	// 扫描也改变计划版本；遇到 CAS 冲突读取新状态，再以新操作身份重试暂停。
	for {
		current, err := client.GetSchedule(ctx, created.Schedule.ID)
		if err != nil {
			return err
		}
		key, err := orbit.NewWorkerMessageID()
		if err != nil {
			return err
		}
		paused, err := client.PauseSchedule(ctx, current.ID, key, orbit.ControlScheduleRequest{ExpectedRevision: current.Revision, Reason: "example finished"})
		if err == nil {
			fmt.Printf("paused=%t completed_tasks=%d current_version=%d\n", paused.Schedule.Paused, len(completed), paused.Schedule.CurrentVersion)
			break
		}
		var apiErr *orbit.APIError
		if !errors.As(err, &apiErr) || apiErr.Code != "STATE_CONFLICT" {
			return err
		}
	}
	stop()
	err = <-done
	waited = true
	if err != nil {
		return err
	}
	fmt.Printf("worker_drained=true running=%d\n", worker.Stats().Running)
	return nil
}