// history 创建一次受控的冲突报告，演示通过公开查询区分权威结果和追加证据。
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 c struct {
			Token   string `json:"token"`
			QueueID string `json:"queue_id"`
		}
		if json.Unmarshal(raw, &c) != nil {
			return errors.New("invalid credentials file")
		}
		if token == "" {
			token = c.Token
		}
		if queue == "" {
			queue = c.QueueID
		}
	}
	client, err := orbit.NewClient(os.Getenv("ORBIT_URL"), orbit.Options{Token: token})
	if err != nil {
		return err
	}
	op, err := orbit.NewWorkerMessageID()
	if err != nil {
		return err
	}
	handler := "history.inspect." + op
	ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
	defer cancel()
	accepted, err := client.SubmitTask(ctx, "history-"+op, orbit.SubmitTaskRequest{QueueID: queue, Handler: handler, HandlerVersion: "v1", PayloadVersion: "v1", Payload: json.RawMessage(`{"object_ref":"examples/input"}`), TaskTimeoutMS: 60000, Retry: orbit.RetryPolicy{MaxAttempts: 1, AttemptTimeoutMS: 10000}})
	if err != nil {
		return err
	}
	registration, err := orbit.NewWorkerRegistration(queue, 1, []orbit.WorkerCapability{{Handler: handler, HandlerVersion: "v1", PayloadVersion: "v1"}})
	if err != nil {
		return err
	}
	w, err := client.DialWorker(ctx, registration)
	if err != nil {
		return err
	}
	defer w.Close()
	nextID := func() (string, error) { return orbit.NewWorkerMessageID() }
	id, err := nextID()
	if err != nil {
		return err
	}
	if _, err := w.Capacity(ctx, id, orbit.WorkerCapacity{Sequence: 1, Capacity: 1}); err != nil {
		return err
	}
	a, err := w.NextAssignment(ctx)
	if err != nil {
		return err
	}
	if a.Task.ID != accepted.Task.ID {
		return errors.New("unexpected task")
	}
	id, err = nextID()
	if err != nil {
		return err
	}
	started, err := w.Start(ctx, id, a.Attempt())
	if err != nil {
		return err
	}
	if _, active := started.Lease.ExecutionDeadline(); !active {
		return errors.New("missing current execution authority")
	}
	// 这是故障演示，不对外部系统执行操作；先提交固定的模拟处理结果。
	id, err = nextID()
	if err != nil {
		return err
	}
	original := json.RawMessage(`{"version":"v1","sequence":9007199254740993}`)
	if _, err := w.Finish(ctx, id, orbit.WorkerFinish{Ref: a.Attempt(), Outcome: orbit.WorkerSucceeded, Result: original}); err != nil {
		return err
	}
	// 使用另一消息身份模拟矛盾回报；只能追加证据，不能覆盖先前权威结果。
	id, err = nextID()
	if err != nil {
		return err
	}
	conflict, err := w.Finish(ctx, id, orbit.WorkerFinish{Ref: a.Attempt(), Outcome: orbit.WorkerSucceeded, Result: json.RawMessage(`{"version":"v2"}`)})
	if err != nil {
		return err
	}
	if conflict.Receipt.Disposition != "EVIDENCE_ONLY" {
		return errors.New("conflicting report was not isolated as evidence")
	}
	attempts, err := client.ListTaskAttempts(ctx, a.Task.ID, orbit.HistoryPageRequest{Limit: 20})
	if err != nil {
		return err
	}
	if len(attempts.Items) != 1 {
		return errors.New("expected one attempt")
	}
	detail, err := client.GetTaskAttempt(ctx, a.Task.ID, attempts.Items[0].ID)
	if err != nil {
		return err
	}
	evidence, err := client.ListAttemptEvidence(ctx, a.Task.ID, detail.ID, orbit.HistoryPageRequest{Limit: 20})
	if err != nil {
		return err
	}
	if len(evidence.Items) != 1 {
		return errors.New("expected one evidence record")
	}
	item, err := client.GetAttemptEvidence(ctx, a.Task.ID, detail.ID, evidence.Items[0].ID)
	if err != nil {
		return err
	}
	current, err := client.GetTask(ctx, a.Task.ID)
	if err != nil {
		return err
	}
	if current.State != orbit.TaskSucceeded || string(current.Result) != string(original) || item.Reason != "RESULT_CONFLICT" {
		return errors.New("history did not preserve authoritative outcome")
	}
	id, err = nextID()
	if err != nil {
		return err
	}
	if _, err := w.Capacity(ctx, id, orbit.WorkerCapacity{Sequence: 2, Capacity: 0, Drain: true}); err != nil {
		return err
	}
	fmt.Printf("task=%s state=%s attempts=%d evidence=%d reason=%s disposition=%s\n", current.ID, current.State, len(attempts.Items), len(evidence.Items), item.Reason, item.Disposition)
	return nil
}