refactor: remove proxy API (#1596)

internal/githubmirror/config.go

@@ -0,0 +1,90 @@
+// Package githubmirror rewrites GitHub URLs and executes mirrored operations.
+package githubmirror
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+type Mirror struct {
+	Type      string `json:"type"`
+	URL       string `json:"url"`
+	IsBuiltIn bool   `json:"isBuiltIn"`
+	IsDeleted bool   `json:"isDeleted"`
+}
+type Config struct {
+	Enabled bool     `json:"enabled"`
+	Mirrors []Mirror `json:"mirrors"`
+}
+
+func DefaultConfig() *Config {
+	return &Config{Enabled: true, Mirrors: []Mirror{
+		{Type: "jsdelivr", URL: "https://fastly.jsdelivr.net/gh", IsBuiltIn: true},
+		{Type: "ghProxy", URL: "https://fastgit.cc", IsBuiltIn: true},
+		{Type: "ghProxy", URL: "https://gh-proxy.com", IsBuiltIn: true},
+		{Type: "ghProxy", URL: "https://ghfast.top", IsBuiltIn: true},
+	}}
+}
+func (c *Config) Validate() error {
+	if len(c.Mirrors) > 32 {
+		return fmt.Errorf("too many GitHub mirrors")
+	}
+	for _, mirror := range c.Mirrors {
+		u, err := url.Parse(mirror.URL)
+		if err != nil || u == nil || (u.Scheme != "http" && u.Scheme != "https") || u.Host == "" || u.User != nil || u.RawQuery != "" || u.Fragment != "" {
+			return fmt.Errorf("invalid GitHub mirror URL")
+		}
+		if mirror.Type != "jsdelivr" && mirror.Type != "ghProxy" {
+			return fmt.Errorf("invalid GitHub mirror type: %s", mirror.Type)
+		}
+	}
+	return nil
+}
+
+// Kind describes what a candidate endpoint must support.
+type Kind uint8
+
+const (
+	Resource Kind = iota
+	Repository
+)
+
+// Candidates preserves the official URL first. jsDelivr is only eligible for
+// raw source resources; Git operations use mirrors supporting Git Smart HTTP.
+// GitHub API URLs are never mirrored.
+func Candidates(c *Config, raw string, kind Kind) []string {
+	result := []string{raw}
+	u, err := url.Parse(raw)
+	if err != nil || c == nil || !c.Enabled || u.User != nil || (u.Scheme != "https" && u.Scheme != "http") {
+		return result
+	}
+	if u.Host != "github.com" && u.Host != "raw.githubusercontent.com" {
+		return result
+	}
+	seen := map[string]bool{raw: true}
+	for _, mirror := range c.Mirrors {
+		if mirror.IsDeleted {
+			continue
+		}
+		var candidate string
+		switch mirror.Type {
+		case "ghProxy":
+			candidate = strings.TrimRight(mirror.URL, "/") + "/" + raw
+		case "jsdelivr":
+			if kind == Repository || u.Host != "raw.githubusercontent.com" {
+				continue
+			}
+			parts := strings.SplitN(strings.TrimPrefix(u.EscapedPath(), "/"), "/", 4)
+			if len(parts) != 4 {
+				continue
+			}
+			candidate = strings.TrimRight(mirror.URL, "/") + "/" + parts[0] + "/" + parts[1] + "@" + parts[2] + "/" + parts[3]
+		}
+		if candidate != "" && !seen[candidate] {
+			result = append(result, candidate)
+			seen[candidate] = true
+		}
+	}
+	return result
+}