package taskrun

import (
	"context"
	"sync"
	"time"

	"chat-agent-system/internal/stream"
)

// CreateRequest 创建后台任务运行实例。
type CreateRequest struct {
	SessionID      string
	ProjectID      int64
	UserID         int64
	ClientTurnID   string
	TaskKey        string
	Stage          string
	WorkDir        string
	UserMessage    string
	AssistantMsgID int64
	IncludeDetails bool
	TaskReq        any // *server task payload converted to bizdev request at execution layer
}

// RunRecord 运行实例状态。
// JSON 键与前端约定及 task_runs 列名一致；缺标签时 encoding/json 会输出 PascalCase，
// 前端读 status/error_message 会得到 undefined，断线恢复分支全部失效。
type RunRecord struct {
	RunID              string     `json:"run_id"`
	SessionID          string     `json:"session_id"`
	ProjectID          int64      `json:"project_id"`
	UserID             int64      `json:"user_id"`
	ClientTurnID       string     `json:"client_turn_id"`
	IdempotencyKey     string     `json:"idempotency_key"`
	TaskKey            string     `json:"task_key"`
	Stage              string     `json:"stage"`
	WorkflowInstanceID int64      `json:"workflow_instance_id"`
	StageInstanceID    int64      `json:"stage_instance_id"`
	WorkflowStageKey   string     `json:"workflow_stage_key"`
	Status             string     `json:"status"` // pending | running | completed | failed | cancelled | pending_author_confirmation | blocked_pending_governance | …
	WorkspaceID        string     `json:"workspace_id"`
	AssistantMsgID     int64      `json:"assistant_message_id"`
	WorkerID           string     `json:"worker_id"`
	LeaseExpiresAt     *time.Time `json:"lease_expires_at"`
	CreatedAt          time.Time  `json:"created_at"`
	UpdatedAt          time.Time  `json:"updated_at"`
	ErrorMessage       string     `json:"error_message"`
	Attempt            int        `json:"attempt"`
}

// BuildTaskRunIdempotencyKey 新创建用稳定幂等键；空 client_turn 不设键。
func BuildTaskRunIdempotencyKey(sessionID, clientTurnID string) string {
	if sessionID == "" || clientTurnID == "" {
		return ""
	}
	return "turn:" + sessionID + ":" + clientTurnID
}

// StoredEvent 持久化 SSE 事件（支持重连重放）。
type StoredEvent struct {
	Seq   int64
	Event stream.StreamEvent
}

type activeRun struct {
	record  *RunRecord
	events  []StoredEvent
	nextSeq int64
	subs    map[int]chan StoredEvent
	subSeq  int
	cancel  context.CancelFunc
	done    chan struct{}
	mu      sync.RWMutex
}