// workflow-poll 区分请求失败重试与成功PENDING后的业务轮次，并演示轮次耗尽进入核查。
package main

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"os"
	"sync/atomic"
	"time"

	"git.yuntuo.hk/k2safe/orbit/examples/internal/flowdemo"
	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 {
	api, queue, operation, err := flowdemo.Client()
	if err != nil {
		return err
	}
	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
	defer cancel()
	for _, exhausted := range []bool{false, true} {
		if err := scenario(ctx, api, queue, operation, exhausted); err != nil {
			return err
		}
	}
	return nil
}

func scenario(ctx context.Context, api *orbit.Client, queue, operation string, exhausted bool) error {
	mode, expected := "success", "SUCCEEDED"
	if exhausted {
		mode, expected = "exhausted", "NEEDS_REVIEW"
	}
	operation += "." + mode
	var requests, submissions atomic.Int32
	// 这是本地外部渠道夹具。真实业务应查询已存在的外部作业，不能在轮询里重新提交作业。
	remote := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/jobs/"+operation {
			http.NotFound(w, r)
			return
		}
		if r.Method == "POST" {
			raw, err := io.ReadAll(io.LimitReader(r.Body, 1025))
			var in struct {
				OperationID string `json:"operation_id"`
			}
			if err != nil || len(raw) > 1024 || json.Unmarshal(raw, &in) != nil || in.OperationID != operation {
				http.Error(w, "invalid operation", 400)
				return
			}
			if submissions.Add(1) != 1 {
				http.Error(w, "unexpected repeated submission", 409)
				return
			}
			w.Header().Set("Content-Type", "application/json")
			w.WriteHeader(http.StatusAccepted)
			_ = json.NewEncoder(w).Encode(in)
			return
		}
		if r.Method != "GET" || submissions.Load() != 1 {
			http.NotFound(w, r)
			return
		}
		n := requests.Add(1)
		if !exhausted && n == 1 {
			http.Error(w, "temporary query failure", http.StatusServiceUnavailable)
			return
		}
		state := "PENDING"
		if !exhausted && n >= 3 {
			state = "DONE"
		}
		w.Header().Set("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(state)
	}))
	defer remote.Close()
	input, _ := json.Marshal(struct {
		OperationID string `json:"operation_id"`
	}{operation})
	typ := orbit.WorkflowType{Kind: "OBJECT", Fields: map[string]orbit.WorkflowType{"operation_id": {Kind: "STRING"}}}
	status := orbit.WorkflowType{Kind: "STRING", Enum: []string{"PENDING", "DONE"}}
	handler := "job.query." + operation
	task := orbit.WorkflowTask{QueueID: queue, Handler: handler, HandlerVersion: "v1", PayloadVersion: "v1", InputType: typ, Input: orbit.WorkflowRef("input"), ResultType: status, TimeoutMS: 20000, Retry: orbit.RetryPolicy{MaxAttempts: 2, InitialDelayMS: 1000, MaxDelayMS: 1000, AttemptTimeoutMS: 5000}, RecoverySafety: orbit.RecoveryIdempotent}
	submit := task
	submit.Handler, submit.ResultType, submit.RecoverySafety = "job.submit."+operation, typ, orbit.RecoveryReconcileOnly
	submit.Retry = orbit.RetryPolicy{MaxAttempts: 1, AttemptTimeoutMS: 5000}
	task.Input = orbit.WorkflowRef("submit")
	spec := orbit.WorkflowSpecification{SchemaVersion: 1, InputType: typ, TimeoutMS: 45000, FailurePolicy: "REVIEW", Body: orbit.WorkflowBlock{Steps: []orbit.WorkflowStep{{Key: "submit", Kind: "TASK", Task: &submit}, {Key: "query", Kind: "POLL", Poll: &orbit.WorkflowPoll{Task: task, MaxRounds: 2, TimeoutMS: 30000, IntervalMS: 1000, Pending: []string{"PENDING"}, Succeeded: []string{"DONE"}}}}, OutputType: status, Output: orbit.WorkflowRef("query")}}
	v, err := flowdemo.PublishStart(ctx, api, operation, "poll."+mode, spec, input)
	if err != nil {
		return err
	}
	httpClient := remote.Client()
	httpClient.Timeout = 3 * time.Second
	runner, err := flowdemo.StartWorker(ctx, api, queue, orbit.WorkerHandler{Capability: orbit.WorkerCapability{Handler: handler, HandlerVersion: "v1", PayloadVersion: "v1"}, Handle: func(ctx context.Context, e orbit.WorkerExecution) (json.RawMessage, error) {
		var in struct {
			OperationID string `json:"operation_id"`
		}
		if json.Unmarshal(e.Task.Payload, &in) != nil || in.OperationID != operation {
			return nil, &orbit.WorkerFailure{Code: "INVALID_JOB"}
		}
		req, err := http.NewRequestWithContext(ctx, "GET", remote.URL+"/jobs/"+in.OperationID, nil)
		if err != nil {
			return nil, err
		}
		resp, err := httpClient.Do(req)
		if err != nil {
			return nil, err
		} // 未知传输错误保留UNKNOWN，由冻结安全策略处理。
		defer resp.Body.Close()
		if resp.StatusCode == http.StatusServiceUnavailable {
			// 本例渠道明确拒绝只读查询，可以声明请求失败且允许Pulse重试。
			return nil, &orbit.WorkerFailure{Code: "QUERY_TEMPORARY", Retryable: true}
		}
		if resp.StatusCode != http.StatusOK {
			return nil, errors.New("unexpected query response")
		}
		raw, err := io.ReadAll(io.LimitReader(resp.Body, 1025))
		if err != nil {
			return nil, err
		}
		var state string
		if len(raw) > 1024 || json.Unmarshal(raw, &state) != nil || state != "PENDING" && state != "DONE" {
			return nil, errors.New("invalid query result")
		}
		return json.RawMessage(raw), nil // PENDING是成功查询结果，不能转为可重试错误。
	}}, orbit.WorkerHandler{Capability: orbit.WorkerCapability{Handler: submit.Handler, HandlerVersion: "v1", PayloadVersion: "v1"}, Handle: func(ctx context.Context, e orbit.WorkerExecution) (json.RawMessage, error) {
		req, err := http.NewRequestWithContext(ctx, "POST", remote.URL+"/jobs/"+operation, bytes.NewReader(e.Task.Payload))
		if err != nil {
			return nil, err
		}
		resp, err := httpClient.Do(req)
		if err != nil {
			return nil, err
		} // 提交结果未知必须核查，不能交给POLL重新提交。
		defer resp.Body.Close()
		if resp.StatusCode != http.StatusAccepted {
			return nil, errors.New("submission receipt unavailable")
		}
		raw, err := io.ReadAll(io.LimitReader(resp.Body, 1025))
		if err != nil {
			return nil, err
		}
		var accepted struct {
			OperationID string `json:"operation_id"`
		}
		if len(raw) > 1024 || json.Unmarshal(raw, &accepted) != nil || accepted.OperationID != operation {
			return nil, errors.New("submission identity mismatch")
		}
		return json.RawMessage(raw), nil
	}})
	if err != nil {
		return err
	}
	defer runner.Close()
	initial, err := runner.Step(ctx, api, v.ID, "query", func(d orbit.WorkflowStepDetail) bool { return d.Poll != nil && d.Step.ActivationID != nil })
	if err != nil {
		return err
	}
	final, err := runner.Workflow(ctx, api, v.ID, expected)
	if err != nil {
		return err
	}
	step, err := api.GetWorkflowStep(ctx, v.ID, "query")
	if err != nil {
		return err
	}
	if step.Poll == nil || step.Step.ActivationID == nil || step.Poll.UsedRounds != 2 || step.Poll.MaxAttemptsPerRound != 2 || !step.Poll.DeadlineAt.Equal(initial.Poll.DeadlineAt) || !final.DeadlineAt.Equal(v.DeadlineAt) || *step.Step.ActivationID != *initial.Step.ActivationID {
		return errors.New("poll budget, deadline or activation changed")
	}
	// 历史按业务轮倒序；每轮再独立读取Pulse尝试，二者不可混为同一个计数。
	cursor, rounds, totalAttempts := "", 0, 0
	for {
		page, err := api.ListWorkflowPollRounds(ctx, v.ID, "query", *step.Step.ActivationID, orbit.HistoryPageRequest{Limit: 1, Cursor: cursor})
		if err != nil {
			return err
		}
		for _, round := range page.Items {
			rounds++
			source, err := api.GetTaskSource(ctx, round.TaskID)
			if err != nil {
				return err
			}
			if source.Workflow == nil || source.Workflow.WorkflowID != v.ID || source.Workflow.PollRound != round.Round {
				return errors.New("query round source mismatch")
			}
			attempts, err := api.ListTaskAttempts(ctx, round.TaskID, orbit.HistoryPageRequest{Limit: 10})
			if err != nil {
				return err
			}
			want := 1
			if !exhausted && round.Round == 1 {
				want = 2
			}
			if len(attempts.Items) != want || attempts.NextCursor != "" {
				return errors.New("request retries consumed wrong business rounds")
			}
			for i, a := range attempts.Items {
				expect := "SUCCEEDED"
				if want == 2 && i == 1 {
					expect = "FAILED"
				}
				if string(a.State) != expect || a.EndedAt == nil {
					return errors.New("unexpected request attempt history")
				}
			}
			totalAttempts += len(attempts.Items)
		}
		if page.NextCursor == "" {
			break
		}
		cursor = page.NextCursor
	}
	expectedRequests := 3
	if exhausted {
		expectedRequests = 2
	}
	if rounds != 2 || totalAttempts != expectedRequests || int(requests.Load()) != expectedRequests || submissions.Load() != 1 {
		return errors.New("unexpected query count")
	}
	if !exhausted && string(final.Output) != `"DONE"` {
		return errors.New("final business result missing")
	}
	if exhausted && (step.Step.State != "NEEDS_REVIEW" || step.Poll.CurrentTaskID != nil || step.Poll.NextPollAt != nil) {
		return errors.New("exhausted poll remained runnable")
	}
	if err := runner.Close(); err != nil {
		return err
	}
	stats := runner.Worker.Stats()
	if int(stats.Started) != expectedRequests+1 || int(stats.ReportsConfirmed) != expectedRequests+1 || stats.Running != 0 {
		return errors.New("Worker did not drain all requests")
	}
	fmt.Printf("poll_scenario=%s state=%s submissions=%d rounds=%d attempts=%d requests=%d deadline_preserved=true worker_drained=true\n", mode, final.State, submissions.Load(), rounds, totalAttempts, requests.Load())
	return nil
}