// Copyright 2013 gopm authors.
//
// Licensed under the Apache License, Version 2.0 (the "License"): you may
// not use this file except in compliance with the License. You may obtain
// a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.

package cmd

import (
	"errors"
	"fmt"
	"github.com/Unknwon/com"
	"github.com/gpmgo/gopm/doc"
	"github.com/syndtr/goleveldb/leveldb"
	"github.com/syndtr/goleveldb/leveldb/opt"
	"io/ioutil"
	"net/http"
	"net/url"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
	"time"
)

var (
	dbDir = "~/.gopm/db"
)

const (
	STOP = iota
	LOCALRUN
	RUNNING
)

var CmdServe = &Command{
	UsageLine: "serve [:port]",
	Short:     "serve for package search",
	Long: `
	serve provide a web service to search packages, download packages 

The serve flags are:

	-l
		only service for localhost ip
`,
}

func init() {
	CmdServe.Run = runServe
	CmdServe.Flags = map[string]bool{
		"-l": false,
	}
}

func printServePrompt(flag string) {
	switch flag {
	case "-l":
		com.ColorLog("[INFO] You enabled start a service only localhost.\n")
	}
}

// Not implemented
func autoPort() string {
	return "8991"
}

func exePath() (string, error) {
	file, err := exec.LookPath(os.Args[0])
	if err != nil {
		return "", err
	}

	return filepath.Abs(file)
}

// search packages
func runServe(cmd *Command, args []string) {
	// Check flags.
	num := checkFlags(cmd.Flags, args, printServePrompt)
	if num == -1 {
		return
	}
	args = args[num:]

	var listen string
	var port string
	if cmd.Flags["-l"] {
		listen += "127.0.0.1"
		port = autoPort()
	} else {
		listen += "0.0.0.0"
		port = "8991"
	}

	// Check length of arguments.
	if len(args) >= 1 {
		port = args[0]
	}

	err := startService(listen, port)
	if err != nil {
		com.ColorLog("[ERRO] %v\n", err)
	}
}

func splitWord(word string, res *map[string]bool) {
	for i, _ := range word {
		for j, _ := range word[i:] {
			w := word[i : i+j+1]
			(*res)[w] = true
		}
	}
	return
}

func splitPkgName(pkgName string) (res map[string]bool) {
	//var src string
	ps := strings.Split(pkgName, "/")
	if len(ps) > 1 {
		ps = ps[1:]
	}

	res = make(map[string]bool)
	res[strings.Join(ps, "/")] = true
	for _, w := range ps {
		splitWord(w, &res)
	}
	return
}

func splitSynopsis(synopsis string) map[string]bool {
	res := make(map[string]bool)
	ss := strings.Fields(synopsis)
	for _, s := range ss {
		res[s] = true
	}
	return res
}

var (
	ro *opt.ReadOptions  = &opt.ReadOptions{}
	wo *opt.WriteOptions = &opt.WriteOptions{}
)

func dbGet(key string) (string, error) {
	v, err := db.Get([]byte(key), ro)
	return string(v), err
}

func dbPut(key string, value string) error {
	//fmt.Println("put ", key, ": ", value)
	return db.Put([]byte(key), []byte(value), wo)
}

func batchPut(batch *leveldb.Batch, key string, value string) error {
	//fmt.Println("put ", key, ": ", value)
	batch.Put([]byte(key), []byte(value))
	return nil
}

func getServeHost() string {
	return "localhost"
}

func getServePort() string {
	return "8991"
}

// for exernal of serve to add node to db
func saveNode(nod *doc.Node) error {
	urlPath := fmt.Sprintf("http://%v:%v/add", getServeHost(), getServePort())
	resp, err := http.PostForm(urlPath,
		url.Values{"importPath": {nod.ImportPath},
			"synopsis":    {nod.Synopsis},
			"downloadURL": {nod.DownloadURL},
			"isGetDeps":   {strconv.FormatBool(nod.IsGetDeps)},
			"type":        {nod.Type},
			"value":       {nod.Value}})

	if err != nil {
		com.ColorLog("[ERRO] Fail to save node[ %s ]\n", err)
		return err
	}
	defer resp.Body.Close()

	if resp.StatusCode == 200 {
		return nil
	}
	return errors.New("save node failed with " + resp.Status)
}

// for inetrnal of serve to add node to db
func addNode(nod *doc.Node) error {
	batch := new(leveldb.Batch)
	strLastId, err := dbGet("lastId")
	if err != nil {
		if err == leveldb.ErrNotFound {
			strLastId = "0"
			err = batchPut(batch, "lastId", strLastId)
		} else {
			return err
		}
	}
	if err != nil {
		return err
	}

	lastId, err := strconv.ParseInt(strLastId, 0, 64)
	if err != nil {
		return err
	}

	nodKey := fmt.Sprintf("index:%v", nod.ImportPath)

	id, err := dbGet(nodKey)
	if err != nil {
		if err == leveldb.ErrNotFound {
			id = fmt.Sprintf("%v", lastId+1)
			err = batchPut(batch, "lastId", id)
			if err == nil {
				err = batchPut(batch, nodKey, id)
			}
			if err == nil {
				err = batchPut(batch, "pkg:"+id, nod.ImportPath)
			}
			if err == nil {
				err = batchPut(batch, "desc:"+id, nod.Synopsis)
			}
			if err == nil {
				err = batchPut(batch, "down:"+id, nod.DownloadURL)
			}
			if err == nil {
				err = batchPut(batch, "deps:"+id, strconv.FormatBool(nod.IsGetDeps))
			}

			// save totals
			total, err := dbGet("total")
			if err != nil {
				if err == leveldb.ErrNotFound {
					total = "1"
				} else {
					return err
				}
			} else {
				totalInt, err := strconv.ParseInt(total, 0, 64)
				if err != nil {
					return err
				}
				totalInt = totalInt + 1
				total = fmt.Sprintf("%v", totalInt)
			}

			err = batchPut(batch, "total", total)
		} else {
			return err
		}
	}

	if err != nil {
		return err
	}

	// save vers
	vers, err := dbGet("ver:" + id)
	needSplit := (err == leveldb.ErrNotFound)
	if err != nil {
		if err != leveldb.ErrNotFound {
			return err
		}
	} else {
		return nil
	}

	if vers == "" {
		//fmt.Println(nod)
		vers = nod.VerString()
	} else {
		if !strings.Contains(vers, nod.VerString()) {
			vers = vers + "," + nod.VerString()
		} else {
			return nil
		}
	}

	err = batchPut(batch, "ver:"+id, vers)
	if err != nil {
		return err
	}

	if !needSplit {
		return nil
	}

	// indexing package name
	keys := splitPkgName(nod.ImportPath)
	for key, _ := range keys {
		err = batchPut(batch, fmt.Sprintf("key:%v:%v", strings.ToLower(key), id), "")
		if err != nil {
			return err
		}
	}

	if nod.Synopsis != "" {
		fields := splitSynopsis(nod.Synopsis)
		for field, _ := range fields {
			err = batchPut(batch, fmt.Sprintf("key:%v:%v", strings.ToLower(field), id), "")
			if err != nil {
				return err
			}
		}
	}

	return db.Write(batch, wo)
}

func rmPkg(nod *doc.Node) {

}

var db *leveldb.DB

// service should be run
func AutoRun() error {
	s, _, _ := runningStatus()
	if s == STOP {
		// current path
		curPath, err := os.Getwd()
		if err != nil {
			return err
		}

		attr := &os.ProcAttr{
			Dir: curPath,
			Env: os.Environ(),
			//Files: []*os.File{nil, nil, nil},
			Files: []*os.File{os.Stdin, os.Stdout, os.Stderr},
		}

		p, err := exePath()
		if err != nil {
			return err
		}

		//com.ColorLog("[INFO] now is starting search daemon ...\n")
		_, err = os.StartProcess(p, []string{"gopm", "serve", "-l"}, attr)
		if err != nil {
			return err
		}
		time.Sleep(time.Second)
	}
	return nil
}

func runningStatus() (int, int, int) {
	pFile, err := getPidPath()
	if err != nil {
		return STOP, 0, 0
	}

	contentByte, err := ioutil.ReadFile(pFile)
	if err != nil {
		return STOP, 0, 0
	}
	content := string(contentByte)
	if len(content) < 0 || !strings.Contains(content, ",") {
		return STOP, 0, 0
	}
	cs := strings.Split(string(content), ",")
	if len(cs) != 3 {
		return STOP, 0, 0
	}
	status, err := strconv.Atoi(cs[0])
	if err != nil {
		return STOP, 0, 0
	}
	if status < STOP || status > RUNNING {
		return STOP, 0, 0
	}
	pid, err := strconv.Atoi(cs[1])
	if err != nil {
		return STOP, 0, 0
	}

	_, err = os.FindProcess(pid)
	if err != nil {
		return STOP, 0, 0
	}

	port, err := strconv.Atoi(cs[2])
	if err != nil {
		return STOP, 0, 0
	}

	return status, pid, port
}

func getPidPath() (string, error) {
	homeDir, err := com.HomeDir()
	if err != nil {
		return "", err
	}

	pFile := strings.Replace("~/.gopm/var/", "~", homeDir, -1)
	os.MkdirAll(pFile, os.ModePerm)
	return pFile + "pid", nil
}

func startService(listen, port string) error {
	homeDir, err := com.HomeDir()
	if err != nil {
		return err
	}

	pFile, err := getPidPath()
	if err != nil {
		return err
	}

	f, err := os.OpenFile(pFile, os.O_RDWR|os.O_CREATE, 0700)
	if err != nil {
		return err
	}
	defer f.Close()
	_, err = f.WriteString(fmt.Sprintf("%v,%v,%v", RUNNING, os.Getpid(), port))
	if err != nil {
		return err
	}

	dbDir = strings.Replace(dbDir, "~", homeDir, -1)

	db, err = leveldb.OpenFile(dbDir, nil)
	if err != nil {
		return err
	}
	defer db.Close()

	// these handlers should only access by localhost
	http.HandleFunc("/add", addHandler)
	http.HandleFunc("/rm", rmHandler)

	// these handlers can be accessed according listen's ip
	http.HandleFunc("/search", searchHandler)
	http.HandleFunc("/searche", searcheHandler)
	http.ListenAndServe(listen+":"+port, nil)
	return nil
}

func searchHandler(w http.ResponseWriter, r *http.Request) {
	r.ParseForm()
	ids := make(map[string]bool)
	for key, _ := range r.Form {
		iter := db.NewIterator(ro)
		rkey := fmt.Sprintf("key:%v:", strings.ToLower(key))
		if iter.Seek([]byte(rkey)) {
			k := iter.Key()
			if !strings.HasPrefix(string(k), rkey) {
				break
			} else {
				ids[string(k)] = true
			}
		}
		for iter.Next() {
			k := iter.Key()
			if !strings.HasPrefix(string(k), rkey) {
				break
			}
			ids[string(k)] = true
		}
	}

	pkgs := make([]string, 0)

	for id, _ := range ids {
		idkeys := strings.SplitN(id, ":", -1)
		rId := idkeys[len(idkeys)-1]
		//fmt.Println(rId)
		pkg, err := dbGet(fmt.Sprintf("pkg:%v", rId))
		if err != nil {
			com.ColorLog(err.Error())
			continue
		}
		desc, err := dbGet(fmt.Sprintf("desc:%v", rId))
		if err != nil {
			com.ColorLog(err.Error())
			continue
		}
		pkgs = append(pkgs, fmt.Sprintf(`{"pkg":"%v", "desc":"%v"}`, pkg, desc))
	}

	w.Write([]byte("[" + strings.Join(pkgs, ", ") + "]"))
}

func searcheHandler(w http.ResponseWriter, r *http.Request) {
	//if r.Method == "POST" {
	r.ParseForm()
	pkgs := make([]string, 0)
	for key, _ := range r.Form {
		rId, err := dbGet("index:" + key)
		if err != nil {
			com.ColorLog(err.Error())
			continue
		}

		desc, err := dbGet(fmt.Sprintf("desc:%v", rId))
		if err != nil {
			com.ColorLog(err.Error())
			continue
		}

		pkgs = append(pkgs, fmt.Sprintf(`{"pkg":"%v", "desc":"%v"}`, key, desc))
	}

	w.Write([]byte("[" + strings.Join(pkgs, ", ") + "]"))
	//}
}

func addHandler(w http.ResponseWriter, r *http.Request) {
	//if r.Method == "POST" {
	r.ParseForm()

	nod := new(doc.Node)
	nod.ImportPath = r.FormValue("importPath")
	nod.Synopsis = r.FormValue("synopsis")
	nod.DownloadURL = r.FormValue("downloadURL")
	isGetDeps, err := strconv.ParseBool(r.FormValue("isGetDeps"))
	if err != nil {
		com.ColorLog("[ERRO] SEVER: Cannot get deps")
	}
	nod.IsGetDeps = isGetDeps
	nod.Type = r.FormValue("type")
	nod.Value = r.FormValue("value")

	err = addNode(nod)
	if err != nil {
		com.ColorLog("[ERRO] SEVER: Cannot add node[ %s ]\n", err)
	}
	//}
}

func rmHandler(w http.ResponseWriter, r *http.Request) {

}