package flow

import (
	"ai-agent/workflow/model/entity"
	"net/url"
	"path/filepath"
	"strings"
)

// FindEndNodes 从指定起始节点开始，遍历图找到所有末端节点（没有出边的节点）
func FindEndNodes(startNodeId string, edges []entity.FlowEdge) []string {
	nextMap := make(map[string][]string)
	for _, e := range edges {
		nextMap[e.From] = append(nextMap[e.From], e.To)
	}

	endNodeSet := make(map[string]struct{})
	visited := make(map[string]struct{})
	queue := []string{startNodeId}

	for len(queue) > 0 {
		node := queue[0]
		queue = queue[1:]

		if _, exist := visited[node]; exist {
			continue
		}
		visited[node] = struct{}{}

		nextList := nextMap[node]
		if len(nextList) == 0 {
			endNodeSet[node] = struct{}{}
			continue
		}
		queue = append(queue, nextList...)
	}

	res := make([]string, 0, len(endNodeSet))
	for k := range endNodeSet {
		res = append(res, k)
	}
	return res
}

// ExtractFlowNodeFrom 从 FlowInfo 中提取节点列表（返回指针切片）
func ExtractFlowNodeFrom(flowContent *entity.FlowInfo) []*entity.FlowNode {
	var flowNodes []*entity.FlowNode
	for _, item := range flowContent.Nodes {
		flowNodes = append(flowNodes, &item)
	}
	return flowNodes
}

// GetFileTypeByPath 根据文件路径/URL的后缀名判断文件类型
func GetFileTypeByPath(filePath string) string {
	if filePath == "" {
		return ""
	}

	// 解析 URL，获取真实路径（兼容 http 链接）
	u, err := url.Parse(filePath)
	if err == nil {
		filePath = u.Path
	}

	// 获取后缀（小写）
	ext := filepath.Ext(filePath)
	ext = strings.ToLower(ext)

	// 判断类型
	switch ext {
	case ".jpg", ".jpeg", ".png", ".gif", ".bmp", ".webp":
		return "image"
	case ".mp4", ".mov", ".avi", ".flv", ".wmv", ".mkv":
		return "video"
	case ".mp3", ".wav", ".m4a", ".flac", ".aac", ".ogg":
		return "audio"
	case ".txt", ".md", ".log", ".json", ".xml", ".inc":
		return "text"
	case ".html":
		return "html"
	case ".pdf", ".doc", ".docx", ".xls", ".xlsx", ".ppt", ".pptx":
		return "document"
	default:
		return ""
	}
}