package proxy

import (
	"fmt"
	"ghproxy/config"
	"strings"

	"github.com/infinite-iroha/touka"
)

func buildProxyPath(path, matcher string) string {
	var sb strings.Builder
	sb.Grow(len(path) + 50)

	if matcher == "blob" && strings.HasPrefix(path, "github.com") {
		sb.WriteString("https://raw.githubusercontent.com")
		pathSegment := path[len("github.com"):]
		if i := strings.Index(pathSegment, "/blob/"); i != -1 {
			sb.WriteString(pathSegment[:i])
			sb.WriteByte('/')
			sb.WriteString(pathSegment[i+len("/blob/"):])
		} else {
			sb.WriteString(pathSegment)
		}
		return sb.String()
	}

	sb.WriteString("https://")
	sb.WriteString(path)
	return sb.String()
}

func normalizeProxyPath(rawPath string) (string, bool) {
	path := strings.TrimLeft(rawPath, "/")

	switch {
	case strings.HasPrefix(path, "https:"):
		path = path[len("https:"):]
	case strings.HasPrefix(path, "http:"):
		path = path[len("http:"):]
	}

	path = strings.TrimLeft(path, "/")
	return path, path != ""
}

func NoRouteHandler(cfg *config.Config) touka.HandlerFunc {
	return func(c *touka.Context) {
		var ctx = c.Request.Context()
		var shoudBreak bool

		path, ok := normalizeProxyPath(c.GetRequestURI())

		// 匹配路径错误处理
		if !ok {
			c.Warnf("%s %s %s %s %s Invalid URL", c.ClientIP(), c.Request.Method, c.Request.URL.Path, c.UserAgent(), c.Request.Proto)
			ErrorPage(c, NewErrorWithStatusLookup(400, fmt.Sprintf("Invalid URL Format: %s", c.GetRequestURI())))
			return
		}

		var matcherErr *GHProxyErrors
		user, repo, matcher, matcherErr := Matcher("https://"+path, cfg)
		if matcherErr != nil {
			ErrorPage(c, matcherErr)
			return
		}

		rawPath := buildProxyPath(path, matcher)

		shoudBreak = listCheck(cfg, c, user, repo, rawPath)
		if shoudBreak {
			return
		}

		shoudBreak = authCheck(c, cfg, matcher, rawPath)
		if shoudBreak {
			return
		}

		// 处理blob/raw路径
		if matcher == "blob" {
			matcher = "raw"
		}

		switch matcher {
		case "releases", "blob", "raw", "gist", "api":
			ChunkedProxyRequest(ctx, c, rawPath, cfg, matcher)
		case "clone":
			GitReq(ctx, c, rawPath, cfg, "git")
		default:
			ErrorPage(c, NewErrorWithStatusLookup(500, "Matched But Not Matched"))
			c.Errorf("Matched But Not Matched Path: %s rawPath: %s matcher: %s", c.GetRequestURIPath(), rawPath, matcher)
			return
		}
	}
}