package contentreviewser

import (
	"fmt"

	"91porn-server/common/log"
	"91porn-server/models/v/contentreviewmod"

	"go.mongodb.org/mongo-driver/bson/primitive"
)

const scanBatchSize = 100

// ScanResult 一批扫描的产出
type ScanResult struct {
	Issues  []*contentreviewmod.ReviewIssue // 本批生成的命中记录
	Checked int64                           // 本批实际扫描的目标数量
	NextID  primitive.ObjectID              // 下一批的游标
	Done    bool                            // true 表示已扫完，runScan 退出循环
}

// Scanner 内容审查扫描策略；具体任务类型实现各自的 ScanBatch
type Scanner interface {
	CountTotal() (int64, error)
	ScanBatch(taskID, lastID primitive.ObjectID, terms []string) (*ScanResult, error)
}

// newScanner Strategy 工厂：根据任务类型返回具体扫描器
func newScanner(taskType string) (Scanner, error) {
	switch taskType {
	case contentreviewmod.TaskTypeVideo:
		return &videoScanner{}, nil
	case contentreviewmod.TaskTypeACG:
		return &acgScanner{}, nil
	default:
		return nil, fmt.Errorf("unsupported task type: %s", taskType)
	}
}

// runScan Template Method：把"分页游标 + 进度回写 + 批量插入"骨架抽出，差异由 Scanner 提供
// 支持从 task.LastTargetID 断点续跑
func runScan(task *contentreviewmod.ReviewTask) (int64, int64, error) {
	scanner, err := newScanner(task.TaskType)
	if err != nil {
		return task.CheckedCount, task.IssueCount, err
	}

	terms := allTerms(task.SnapshotWords)

	total := task.TotalCount
	if total <= 0 {
		t, err := scanner.CountTotal()
		if err != nil {
			return task.CheckedCount, task.IssueCount, fmt.Errorf("count total: %w", err)
		}
		total = t
	}
	// 同步到内存对象，便于 executeTask 拼 TG 消息时正确取值
	task.TotalCount = total

	lastID := task.LastTargetID
	checked := task.CheckedCount
	issues := task.IssueCount

	flushProgress(task.ID, lastID, checked, issues, total)

	for {
		result, err := scanner.ScanBatch(task.ID, lastID, terms)
		if err != nil {
			return checked, issues, fmt.Errorf("scan batch: %w", err)
		}
		if result.Done {
			break
		}
		if len(result.Issues) > 0 {
			if err := contentreviewmod.InsertIssues(result.Issues); err != nil {
				log.Warn("insert issues fail", log.Any("count", len(result.Issues)), log.E(err))
			} else {
				issues += int64(len(result.Issues))
			}
		}
		checked += result.Checked
		lastID = result.NextID

		flushProgress(task.ID, lastID, checked, issues, total)
	}
	return checked, issues, nil
}

func flushProgress(id, lastID primitive.ObjectID, checked, issues, total int64) {
	if err := contentreviewmod.UpdateProgress(id, lastID, checked, issues, total); err != nil {
		log.Warn("update progress fail", log.E(err))
	}
}