//
// Copyright (c) 2019 Ted Unangst <tedu@tedunangst.com>
//
// Permission to use, copy, modify, and distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

package main

import (
	"bufio"
	"crypto/rand"
	"crypto/sha512"
	"database/sql"
	"fmt"
	"io/ioutil"
	"log"
	"net"
	"os"
	"os/signal"
	"strings"

	"golang.org/x/crypto/bcrypt"
	_ "humungus.tedunangst.com/r/go-sqlite3"
)

var savedstyleparam string

func getstyleparam() string {
	if savedstyleparam != "" {
		return savedstyleparam
	}
	data, _ := ioutil.ReadFile("views/style.css")
	hasher := sha512.New()
	hasher.Write(data)
	return fmt.Sprintf("?v=%.8x", hasher.Sum(nil))
}

var dbtimeformat = "2006-01-02 15:04:05"

var alreadyopendb *sql.DB
var dbname = "honk.db"
var stmtConfig *sql.Stmt

func initdb() {
	schema, err := ioutil.ReadFile("schema.sql")
	if err != nil {
		log.Fatal(err)
	}
	_, err = os.Stat(dbname)
	if err == nil {
		log.Fatalf("%s already exists", dbname)
	}
	db, err := sql.Open("sqlite3", dbname)
	if err != nil {
		log.Fatal(err)
	}
	defer func() {
		os.Remove(dbname)
		os.Exit(1)
	}()
	c := make(chan os.Signal)
	signal.Notify(c, os.Interrupt)
	go func() {
		<-c
		fmt.Printf("\x1b[?12;25h\x1b[0m")
		fmt.Printf("\n")
		os.Remove(dbname)
		os.Exit(1)
	}()
	for _, line := range strings.Split(string(schema), ";") {
		_, err = db.Exec(line)
		if err != nil {
			log.Print(err)
			return
		}
	}
	defer db.Close()
	r := bufio.NewReader(os.Stdin)
	fmt.Printf("username: ")
	name, err := r.ReadString('\n')
	if err != nil {
		log.Print(err)
		return
	}
	name = name[:len(name)-1]
	if len(name) < 1 {
		log.Print("that's way too short")
		return
	}
	fmt.Printf("password: \x1b[?25l\x1b[%d;%dm                 \x1b[16D", 30, 40)
	pass, err := r.ReadString('\n')
	fmt.Printf("\x1b[0m\x1b[?12;25h")
	if err != nil {
		log.Fatal(err)
		return
	}
	pass = pass[:len(pass)-1]
	if len(pass) < 6 {
		log.Print("that's way too short")
		return
	}
	hash, err := bcrypt.GenerateFromPassword([]byte(pass), 12)
	if err != nil {
		log.Print(err)
		return
	}
	_, err = db.Exec("insert into users (username, hash) values (?, ?)", name, hash)
	if err != nil {
		log.Print(err)
		return
	}
	fmt.Printf("listen address: ")
	addr, err := r.ReadString('\n')
	if err != nil {
		log.Print(err)
		return
	}
	addr = addr[:len(addr)-1]
	if len(addr) < 1 {
		log.Print("that's way too short")
		return
	}
	_, err = db.Exec("insert into config (key, value) values (?, ?)", "listenaddr", addr)
	if err != nil {
		log.Print(err)
		return
	}
	fmt.Printf("server name: ")
	addr, err = r.ReadString('\n')
	if err != nil {
		log.Print(err)
		return
	}
	addr = addr[:len(addr)-1]
	if len(addr) < 1 {
		log.Print("that's way too short")
		return
	}
	_, err = db.Exec("insert into config (key, value) values (?, ?)", "servername", addr)
	if err != nil {
		log.Print(err)
		return
	}
	var randbytes [16]byte
	rand.Read(randbytes[:])
	key := fmt.Sprintf("%x", randbytes)
	_, err = db.Exec("insert into config (key, value) values (?, ?)", "csrfkey", key)
	if err != nil {
		log.Print(err)
		return
	}
	err = finishusersetup()
	if err != nil {
		log.Print(err)
		return
	}
	db.Exec("insert into config (key, value) values (?, ?)", "debug", 1)
	db.Close()
	fmt.Printf("done.\n")
	os.Exit(0)
}

func opendatabase() *sql.DB {
	if alreadyopendb != nil {
		return alreadyopendb
	}
	var err error
	_, err = os.Stat(dbname)
	if err != nil {
		log.Fatalf("unable to open database: %s", err)
	}
	db, err := sql.Open("sqlite3", dbname)
	if err != nil {
		log.Fatalf("unable to open database: %s", err)
	}
	stmtConfig, err = db.Prepare("select value from config where key = ?")
	if err != nil {
		log.Fatal(err)
	}
	alreadyopendb = db
	return db
}

func getconfig(key string, value interface{}) error {
	row := stmtConfig.QueryRow(key)
	err := row.Scan(value)
	if err == sql.ErrNoRows {
		err = nil
	}
	return err
}

func openListener() (net.Listener, error) {
	var listenAddr string
	err := getconfig("listenaddr", &listenAddr)
	if err != nil {
		return nil, err
	}
	if listenAddr == "" {
		return nil, fmt.Errorf("must have listenaddr")
	}
	proto := "tcp"
	if listenAddr[0] == '/' {
		proto = "unix"
		err := os.Remove(listenAddr)
		if err != nil && !os.IsNotExist(err) {
			log.Printf("unable to unlink socket: %s", err)
		}
	}
	listener, err := net.Listen(proto, listenAddr)
	if err != nil {
		return nil, err
	}
	if proto == "unix" {
		os.Chmod(listenAddr, 0777)
	}
	return listener, nil
}