/*
		GNU GENERAL PUBLIC LICENSE
                 Version 3, 29 June 2007

 Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

 http-wokou, An HTTP Proxying framework for bypassing DNS Security
 Copyright (C) 2024 Russell Hrubesky, ChiralWorks Software LLC

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <https://www.gnu.org/licenses/>.

*/

package httpserver

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"os"
	"time"

	"github.com/patrickmn/go-cache"
)

type HttpServerConfig struct {
	HttpPort             int             `json:"http_port"`
	HttpsPort            int             `json:"https_port"`
	AllowedDomain        string          `json:"allowed_domain"`
	FullDomain           string          // The domain name with the protocol before it
	AltAllowedDomain     string          `json:"alt_allowed_domain"` // alternate domain that resources are sourced from
	FullAltAllowedDomain string          // the alt domain with the protocol
	Proto                string          `json:"proto"` // http/https
	UserAgent            string          `json:"user_agent"`
	SslPemFile           string          `json:"ssl_pem_file"`
	SslKeyFile           string          `json:"ssl_key_file"`
	ListeningIp          string          `json:"listening_ip"`
	ProxyAddr            string          `json:"proxy_addr"`
	RouteMapPath         string          `json:"route_map_path"`
	PageModPath          string          `json:"page_mod_path"`
	CustomFServePath     string          `json:"custom_fileserve_cfg_path"`
	CookieFile           string          `json:"cookie_file"`
	FullProxyDomain      string          // the domain name of the proxied site with the protocol
	KnownHosts           []string        `json:"known_hosts"`
	CorsHosts            []string        `json:"cors_hosts"`
	Redirects            []*RedirectRule `json:"redirects"`
	Caching              bool
	TkUpdateCode         string
	CustomFserve         *CustomFileServer
	TokenSaveLoc         string
	CookieJar            []*http.Cookie
	PhpSession           *http.Cookie
	SsoToken             *http.Cookie
}

type CustomFile struct {
	Request     string `json:"request"`
	Serve       string `json:"serve"`
	ContentType string `json:"content-type"`
	FileData    []byte
}

type CustomFileServer struct {
	Config []*CustomFile `json:"config"`
}

type RedirectRule struct {
	From string `json:"from"`
	To   string `json:"to"`
}

type Cookie struct {
	Name       string `json:"name"`
	Value      string `json:"value"`
	MaxAge     int    `json:"max_age"`
	Path       string `json:"path"`
	Domain     string `json:"domain"`
	Secure     bool   `json:"secure"`
	IncludeSub bool   `json:"include_sub"`
}

/*
Reads the server configuration file, along with the cookie file so that the correlated account can be
accessed through the proxy

	:param loc: the location of the config file
*/
func ReadConfig(loc string) (*HttpServerConfig, error) {

	f, err := os.ReadFile(loc)
	if err != nil {
		return nil, err
	}
	var cfg HttpServerConfig
	err = json.Unmarshal(f, &cfg)
	if err != nil {
		return nil, err
	}
	cf, err := os.ReadFile(cfg.CookieFile)
	if err != nil {
		return nil, err
	}
	cfg.CustomFserve = ReadCustomFiles(cfg.CustomFServePath)
	cfg.FullDomain = fmt.Sprintf("%s://%s", cfg.Proto, cfg.AllowedDomain)
	cfg.FullProxyDomain = fmt.Sprintf("%s://%s", cfg.Proto, cfg.ProxyAddr)
	cfg.FullAltAllowedDomain = fmt.Sprintf("%s://%s", cfg.Proto, cfg.AltAllowedDomain)
	var cookies []*http.Cookie
	err = json.Unmarshal(cf, &cookies)
	if err != nil {
		return nil, err
	}
	for idx := range cookies {
		if cookies[idx].Name == "PHPSESSID" {
			cfg.PhpSession = cookies[idx]
		}
		if cookies[idx].Name == "sso_token" {
			cfg.SsoToken = cookies[idx]
		}

	}
	cfg.CookieJar = cookies

	return &cfg, err

}

func ReadRouteMap(loc string) *RouteMap {
	f, err := os.ReadFile(loc)
	if err != nil {
		log.Fatal(err)
	}
	var mapfile RouteMap
	err = json.Unmarshal(f, &mapfile)
	if err != nil {
		log.Fatal(err)
	}
	mapfile.MapCache = cache.New(24*time.Hour, 10*time.Minute)
	mapfile.populateRouteMaps()
	return &mapfile

}

/*
Read in the custom file server configuration

	:param loc: path to the custom file server config
*/
func ReadCustomFiles(loc string) *CustomFileServer {
	b, err := os.ReadFile(loc)
	if err != nil {
		fmt.Printf("couldnt read custom config file: %s\n", err.Error())
		return nil
	}
	var fserveCfg CustomFileServer
	err = json.Unmarshal(b, &fserveCfg)
	if err != nil {
		log.Fatal("error loading in the config file: ", err)
	}
	for idx := range fserveCfg.Config {
		_, err = os.Stat(fserveCfg.Config[idx].Serve)
		if err != nil {
			log.Fatal("Couldnt verify the existence of file: ", fserveCfg.Config[idx].Serve, " error: ", err)
		}
		b, err = os.ReadFile(fserveCfg.Config[idx].Serve)
		if err != nil {
			log.Fatal("Error reading in custom fileserver file: ", err)
		}
		fserveCfg.Config[idx].FileData = b
	}
	return &fserveCfg
}