package config

import (
	"fmt"
	"os"

	"go.yaml.in/yaml/v3"
)

func GenerateTemplateConfig(writeToFile bool) (Config, error) {
	cfg := Config{
		ServerMode:  "SOCKS5",
		BindAddress: "127.0.0.1",
		Port:        1080,

		LogLevel: "info",

		RewriteMode: "GLOBAL",

		UserAgent:               "FFF",
		UserAgentRegex:          "",
		UserAgentPartialReplace: false,

		IncludeLanRoutes: false,

		L3Rewrite: L3RewriteConfig{
			TTL:        false,
			IPID:       false,
			TCPTS:      false,
			TCPWIN:     false,
			BLOCKQUIC:  false,
			BPFOffload: false,
		},

		Desync: DesyncConfig{
			Reorder:        false,
			ReorderBytes:   8,
			ReorderPackets: 1500,
			Inject:         false,
			InjectTTL:      3,
		},

		MitM: MitMConfig{
			Enabled:            false,
			Hostname:           "",
			CAP12:              "",
			CAPassphrase:       "",
			InsecureSkipVerify: false,
		},

		HeaderRules: []Rule{
			{
				Type:          "FINAL",
				Action:        "REPLACE",
				RewriteHeader: "User-Agent",
				RewriteValue:  "FFF",
			},
		},

		BodyRules: []Rule{
			{
				Type:             "URL-REGEX",
				MatchValue:       "^http://ua-check.stagoh.com",
				Action:           "REPLACE-REGEX",
				RewriteDirection: "RESPONSE",
				RewriteRegex:     "User-Agent",
				RewriteValue:     "UA3F",
			},
		},

		URLRedirectRules: []Rule{
			{
				Type:         "URL-REGEX",
				MatchValue:   "^http://example.com/old-path",
				Action:       "REDIRECT-302",
				RewriteRegex: "http://example.com/old-path(.*)",
				RewriteValue: "http://example.com/new-path$1",
			},
		},
	}

	if writeToFile {
		data, err := yaml.Marshal(&cfg)
		if err != nil {
			return Config{}, fmt.Errorf("failed to marshal template config to YAML: %w", err)
		}
		if err := os.WriteFile("config.yaml", data, 0644); err != nil {
			return Config{}, fmt.Errorf("failed to write template config to file: %w", err)
		}
	}
	return cfg, nil
}