package service

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

	"infinite-canvas/backend/internal/model"
	"infinite-canvas/backend/internal/repository"
)

const providerTaskRecoveryLeaseDuration = 10 * time.Minute

type ProviderTaskQueryResult struct {
	Task           *model.Task `json:"task"`
	ProviderStatus string      `json:"providerStatus"`
	Recovered      bool        `json:"recovered"`
	BillingSettled bool        `json:"billingSettled"`
}

func (s *Service) QueryFailedVideoTask(ctx context.Context, userID string, taskID string) (*ProviderTaskQueryResult, error) {
	task, err := s.repo.TaskForUser(strings.TrimSpace(userID), strings.TrimSpace(taskID))
	if err != nil {
		return nil, err
	}
	return s.queryFailedVideoTask(ctx, task, strings.TrimSpace(userID))
}

func (s *Service) AdminQueryFailedVideoTask(ctx context.Context, actor *model.User, logID string) (*ProviderTaskQueryResult, error) {
	if err := s.RequireAdmin(actor); err != nil {
		return nil, err
	}
	log, err := s.repo.APICallLog(strings.TrimSpace(logID))
	if err != nil {
		return nil, err
	}
	if log.Capability != "video" || strings.TrimSpace(log.TaskID) == "" {
		return nil, BadAuthRequest("该请求没有可查询的视频任务")
	}
	task, err := s.repo.Task(log.TaskID)
	if err != nil {
		return nil, err
	}
	if task.UserID != log.UserID {
		return nil, BadAuthRequest("请求与任务归属不一致")
	}
	if task.ProviderRequestID == "" {
		task.ProviderRequestID = strings.TrimSpace(log.ProviderRequestID)
	}
	result, err := s.queryFailedVideoTask(ctx, task, "")
	if err != nil {
		return nil, err
	}
	if err := s.appendAdminAudit(actor, "api_log.query_provider_task", "task", task.ID, "人工查询失败视频任务", map[string]any{
		"apiCallLogId": log.ID, "providerRequestId": task.ProviderRequestID, "providerStatus": result.ProviderStatus, "recovered": result.Recovered,
	}); err != nil {
		return nil, err
	}
	return result, nil
}

func (s *Service) queryFailedVideoTask(ctx context.Context, task *model.Task, claimUserID string) (*ProviderTaskQueryResult, error) {
	if task == nil || task.ID == "" {
		return nil, BadAuthRequest("任务不存在")
	}
	if task.Status != model.TaskStatusFailed {
		return nil, BadAuthRequest("只能人工查询状态为失败的任务")
	}
	if !strings.HasPrefix(task.Type, "canvas_video") && !strings.HasPrefix(task.Type, "video_") {
		return nil, BadAuthRequest("该任务不是视频生成任务")
	}

	s.hydrateTaskProviderRequestID(task)
	providerRequestID := strings.TrimSpace(task.ProviderRequestID)
	if providerRequestID == "" {
		return nil, BadAuthRequest("该任务没有可恢复的上游任务 ID")
	}
	if task.BillingOrderID != "" {
		order, err := s.repo.BillingOrder(task.BillingOrderID)
		if err != nil {
			return nil, err
		}
		if order.UserID != task.UserID || order.TaskID != task.ID {
			return nil, BadAuthRequest("任务与计费订单归属不一致")
		}
		if order.Status == model.BillingStatusRefunded {
			return nil, BadAuthRequest("该任务已退款，不能恢复并重新扣费")
		}
	}

	decryptedInput, err := s.decryptTaskInputJSON(task.InputJSON)
	if err != nil {
		return nil, fmt.Errorf("读取任务配置失败：%w", err)
	}
	var input canvasGenerationInput
	if err := json.Unmarshal([]byte(decryptedInput), &input); err != nil {
		return nil, fmt.Errorf("任务输入解析失败：%w", err)
	}
	config, err := s.resolveProviderConfig(input.Config)
	if err != nil {
		return nil, err
	}
	if config.InterfaceType != string(model.ChannelInterfaceNewAPIChannel2) {
		return nil, BadAuthRequest("该任务不使用 NewAPI Video Generations 协议")
	}
	input.Config = config
	task.InputJSON = decryptedInput
	task.ProviderRequestID = providerRequestID
	if err := s.repo.UpdateTaskProviderState(task.ID, providerRequestID, task.PollStage, task.NextPollAt); err != nil {
		return nil, err
	}

	owner := "manual-recovery:" + newID()
	if err := s.repo.ClaimFailedTaskProviderRecovery(task.ID, claimUserID, owner, providerTaskRecoveryLeaseDuration); err != nil {
		if errors.Is(err, repository.ErrTaskProviderRecoveryConflict) {
			return nil, &AuthError{Status: 409, Message: "该任务正在查询上游状态，请稍后再试"}
		}
		return nil, err
	}
	task.LeaseOwner = owner
	defer func() { _ = s.repo.ReleaseTaskProviderRecovery(task.ID, owner) }()

	queryCtx := withProviderAnalytics(ctx, s, *task)
	queryCtx = withProviderOutboundPolicy(queryCtx, input.Config)
	result, providerStatus, err := queryNewAPIChannel2VideoTask(queryCtx, input, providerRequestID)
	if err != nil {
		_ = s.log(task.UserID, task.ID, "error", "人工查询上游视频任务失败", err.Error())
		return nil, err
	}
	if result == nil {
		_ = s.log(task.UserID, task.ID, "info", "人工查询完成，上游任务仍在处理", providerStatus)
		return &ProviderTaskQueryResult{Task: taskForOutput(*task), ProviderStatus: providerStatus, Recovered: false}, nil
	}

	result, err = s.persistGeneratedMediaResult(task.UserID, result)
	if err != nil {
		_ = s.log(task.UserID, task.ID, "error", "人工查询已取得视频，但结果保存失败", err.Error())
		return nil, err
	}
	resultJSON, err := json.Marshal(result)
	if err != nil {
		return nil, err
	}
	task.Error = ""
	task.PollStage = strings.ToLower(providerStatus)
	task.NextPollAt = nil
	if err := s.saveTaskCompletionWithinStorageQuota(task, resultJSON, nil, false); err != nil {
		_ = s.MarkBillingUncertain(task.BillingOrderID, "人工查询确认上游成功，但任务结果未保存："+err.Error())
		_ = s.log(task.UserID, task.ID, "error", "人工查询已取得视频，但任务恢复失败", err.Error())
		return nil, err
	}
	if err := s.RegisterTaskOutputFromTask(*task); err != nil {
		_ = s.log(task.UserID, task.ID, "error", "任务恢复成功但项目产物登记失败", err.Error())
	}
	billingSettled := true
	if err := s.SettleBilling(task.BillingOrderID, providerRequestID); err != nil {
		billingSettled = false
		_ = s.MarkBillingUncertain(task.BillingOrderID, "人工查询确认生成成功，但积分结算失败："+err.Error())
		_ = s.log(task.UserID, task.ID, "error", "任务恢复成功但积分结算失败，已进入待核对", err.Error())
	} else {
		_ = s.log(task.UserID, task.ID, "info", "人工查询确认生成成功，任务已恢复并完成结算", providerStatus)
	}
	return &ProviderTaskQueryResult{Task: taskForOutput(*task), ProviderStatus: providerStatus, Recovered: true, BillingSettled: billingSettled}, nil
}