package main

import (
	"bufio"
	"flag"
	"fmt"
	"log"
	"net"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"time"
)

func main() {
	root := flag.String("root", "/srv/gitpocket", "data directory holding gitpocket.db and repos/")
	flag.Usage = func() {
		fmt.Fprintln(os.Stderr, `usage: gitpocket [-root dir] command

  serve [-listen addr] [-host name] [-name text] [-ssh-user name] [-proxy cidr,...]   run the web server
  keys user home type key                     sshd AuthorizedKeysCommand
  shell user                                  forced command for ssh git access
  invite                                      print a single use registration code
  registration [open|invite|closed]           show or set who may register
  admin name | unadmin name                   grant or revoke site administration
  quota [size]                                show or set the per user disk quota, 0 disables
  user name                                   create a user, password read from stdin
  passwd name                                 set a user's password, read from stdin
  ban name | unban name                       block or restore an account
  delete name                                 remove an account and its repositories
  feature owner/repo... | -owner/repo         set or clear the featured projects, in order
  org name [+user|-user]...                   create an organisation and add or remove members
  mail address                                send a test message through the configured mailer
  backup dir | file.db                        snapshot the database and bundle every changed repository into dir`)
	}
	flag.Parse()
	args := flag.Args()
	if len(args) == 0 {
		flag.Usage()
		os.Exit(2)
	}
	switch args[0] {
	case "serve":
		serve(*root, args[1:])
	case "keys":
		binary, _ := os.Executable()
		os.Exit(keys(*root, binary, args[1:]))
	case "hook":
		if len(args) != 3 {
			os.Exit(2)
		}
		os.Exit(hook(*root, args[1], args[2]))
	case "shell":
		if len(args) != 2 {
			os.Exit(2)
		}
		os.Exit(shell(*root, args[1]))
	case "quota":
		if len(args) == 2 {
			n, err := parseSize(args[1])
			if err != nil {
				log.Fatal(err)
			}
			if err := writeQuota(*root, n); err != nil {
				log.Fatal(err)
			}
		}
		if q := readQuota(*root); q == 0 {
			fmt.Println("no quota")
		} else {
			fmt.Println(humanSize(q))
		}
	case "registration":
		store := mustStore(*root)
		if len(args) == 2 {
			if !validRegistration(args[1]) {
				log.Fatal("registration is open, invite or closed")
			}
			if err := store.SetSetting("registration", args[1]); err != nil {
				log.Fatal(err)
			}
		}
		fmt.Println(store.Registration())
	case "admin", "unadmin":
		if len(args) != 2 {
			os.Exit(2)
		}
		if err := mustStore(*root).SetAdmin(args[1], args[0] == "admin"); err != nil {
			log.Fatal("no such user")
		}
	case "invite":
		store := mustStore(*root)
		code, err := store.CreateInvite()
		if err != nil {
			log.Fatal(err)
		}
		fmt.Println(code)
	case "user":
		if len(args) != 2 {
			os.Exit(2)
		}
		store := mustStore(*root)
		password := readLine()
		if _, err := store.CreateUser(args[1], password); err != nil {
			log.Fatal(err)
		}
	case "passwd":
		if len(args) != 2 {
			os.Exit(2)
		}
		store := mustStore(*root)
		u, err := store.UserByName(args[1])
		if err != nil {
			log.Fatal("no such user")
		}
		password := readLine()
		if err := store.SetPassword(u.ID, password); err != nil {
			log.Fatal(err)
		}
		store.DeleteSessions(u.ID)
	case "backup":
		if len(args) != 2 {
			os.Exit(2)
		}
		if err := backup(*root, args[1], 14); err != nil {
			log.Fatal(err)
		}
	case "mail":
		if len(args) != 2 {
			os.Exit(2)
		}
		if err := loadMailer(*root).Send(args[1], "test message from gitpocket", "Mail delivery from this forge works.\n"); err != nil {
			log.Fatal(err)
		}
		fmt.Println("sent")
	case "org":
		if len(args) < 2 {
			os.Exit(2)
		}
		store := mustStore(*root)
		org, err := store.UserByName(args[1])
		if err != nil {
			if org, err = store.CreateOrg(args[1]); err != nil {
				log.Fatal(err)
			}
		} else if !store.IsOrg(org.ID) {
			log.Fatalf("~%s is a user, not an organisation", args[1])
		}
		for _, spec := range args[2:] {
			name := strings.TrimPrefix(strings.TrimLeft(spec, "+-"), "~")
			u, err := store.UserByName(name)
			if err != nil || store.IsOrg(u.ID) {
				log.Fatalf("%s: no such user", spec)
			}
			if err := store.SetMember(org.ID, u.ID, !strings.HasPrefix(spec, "-")); err != nil {
				log.Fatal(err)
			}
		}
	case "feature":
		if len(args) < 2 {
			os.Exit(2)
		}
		store := mustStore(*root)
		for i, spec := range args[1:] {
			owner, name, ok := strings.Cut(strings.TrimPrefix(spec, "~"), "/")
			rank := i + 1
			if strings.HasPrefix(spec, "-") {
				owner, name, ok = strings.Cut(strings.TrimPrefix(spec, "-~"), "/")
				rank = 0
			}
			if !ok {
				log.Fatalf("%s: expected owner/repo", spec)
			}
			if err := store.SetFeatured(owner, name, rank); err != nil {
				log.Fatalf("%s: no such repository", spec)
			}
		}
	case "ban", "unban":
		if len(args) != 2 {
			os.Exit(2)
		}
		if err := mustStore(*root).SetBanned(args[1], args[0] == "ban"); err != nil {
			log.Fatal(err)
		}
	case "delete":
		if len(args) != 2 {
			os.Exit(2)
		}
		store := mustStore(*root)
		if _, err := store.UserByName(args[1]); err != nil {
			log.Fatal("no such user")
		}
		if err := store.DeleteUser(args[1]); err != nil {
			log.Fatal(err)
		}
		os.RemoveAll(filepath.Join(*root, "repos", args[1]))
	default:
		flag.Usage()
		os.Exit(2)
	}
}

func mustStore(root string) *Store {
	if err := os.MkdirAll(filepath.Join(root, "repos"), 0o755); err != nil {
		log.Fatal(err)
	}
	store, err := openStore(filepath.Join(root, "gitpocket.db"), false)
	if err != nil {
		log.Fatal(err)
	}
	return store
}

func serve(root string, args []string) {
	fs := flag.NewFlagSet("serve", flag.ExitOnError)
	listen := fs.String("listen", "127.0.0.1:3200", "address to listen on")
	host := fs.String("host", "localhost", "public hostname used in clone urls")
	name := fs.String("name", "gitpocket", "site name shown in the header")
	sshUser := fs.String("ssh-user", "git", "unix user that serves git over ssh, shown in clone urls")
	proxies := fs.String("proxy", "", "comma separated networks besides loopback whose X-Forwarded-For is trusted")
	fs.Parse(args)
	for _, cidr := range strings.Split(*proxies, ",") {
		if cidr = strings.TrimSpace(cidr); cidr == "" {
			continue
		}
		_, n, err := net.ParseCIDR(cidr)
		if err != nil {
			log.Fatalf("-proxy %s: %v", cidr, err)
		}
		trustedProxies = append(trustedProxies, n)
	}
	store := mustStore(root)
	srv := &http.Server{
		Addr:              *listen,
		Handler:           newServer(store, root, *host, *name, *sshUser).handler(),
		ReadHeaderTimeout: 10 * time.Second,
		IdleTimeout:       2 * time.Minute,
		MaxHeaderBytes:    64 << 10,
	}
	log.Printf("gitpocket listening on %s for %s", *listen, *host)
	log.Fatal(srv.ListenAndServe())
}

func readLine() string {
	line, _ := bufio.NewReader(os.Stdin).ReadString('\n')
	return strings.TrimRight(line, "\r\n")
}