// Copyright (C) 2014 The Syncthing Authors.
//
// 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 <http://www.gnu.org/licenses/>.

// +build integration

package integration

import (
	"bufio"
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"os"
	"os/exec"
	"time"
)

var env = []string{
	"HOME=.",
	"STGUIAPIKEY=" + apiKey,
	"STNORESTART=1",
}

type syncthingProcess struct {
	log       string
	argv      []string
	port      int
	apiKey    string
	csrfToken string
	lastEvent int

	cmd   *exec.Cmd
	logfd *os.File
}

func (p *syncthingProcess) start() error {
	if p.logfd == nil {
		logfd, err := os.Create(p.log)
		if err != nil {
			return err
		}
		p.logfd = logfd
	}

	cmd := exec.Command("../bin/syncthing", p.argv...)
	cmd.Stdout = p.logfd
	cmd.Stderr = p.logfd
	cmd.Env = append(os.Environ(), env...)

	err := cmd.Start()
	if err != nil {
		return err
	}
	p.cmd = cmd

	for {
		resp, err := p.get("/")
		if err == nil {
			resp.Body.Close()
			return nil
		}
		time.Sleep(250 * time.Millisecond)
	}
}

func (p *syncthingProcess) stop() error {
	p.cmd.Process.Signal(os.Kill)
	p.cmd.Wait()

	fd, err := os.Open(p.log)
	if err != nil {
		return err
	}
	defer fd.Close()

	raceConditionStart := []byte("WARNING: DATA RACE")
	raceConditionSep := []byte("==================")
	sc := bufio.NewScanner(fd)
	race := false
	for sc.Scan() {
		line := sc.Bytes()
		if race {
			fmt.Printf("%s\n", line)
			if bytes.Contains(line, raceConditionSep) {
				race = false
			}
		} else if bytes.Contains(line, raceConditionStart) {
			fmt.Printf("%s\n", raceConditionSep)
			fmt.Printf("%s\n", raceConditionStart)
			race = true
			if err == nil {
				err = errors.New("Race condition detected")
			}
		}
	}
	return err
}

func (p *syncthingProcess) get(path string) (*http.Response, error) {
	client := &http.Client{
		Timeout: 30 * time.Second,
		Transport: &http.Transport{
			DisableKeepAlives: true,
		},
	}
	req, err := http.NewRequest("GET", fmt.Sprintf("http://127.0.0.1:%d%s", p.port, path), nil)
	if err != nil {
		return nil, err
	}
	if p.apiKey != "" {
		req.Header.Add("X-API-Key", p.apiKey)
	}
	if p.csrfToken != "" {
		req.Header.Add("X-CSRF-Token", p.csrfToken)
	}
	resp, err := client.Do(req)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (p *syncthingProcess) post(path string, data io.Reader) (*http.Response, error) {
	client := &http.Client{
		Timeout: 600 * time.Second,
		Transport: &http.Transport{
			DisableKeepAlives: true,
		},
	}
	req, err := http.NewRequest("POST", fmt.Sprintf("http://127.0.0.1:%d%s", p.port, path), data)
	if err != nil {
		return nil, err
	}
	if p.apiKey != "" {
		req.Header.Add("X-API-Key", p.apiKey)
	}
	if p.csrfToken != "" {
		req.Header.Add("X-CSRF-Token", p.csrfToken)
	}
	req.Header.Add("Content-Type", "application/json")

	resp, err := client.Do(req)
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (p *syncthingProcess) peerCompletion() (map[string]int, error) {
	resp, err := p.get("/rest/debug/peerCompletion")
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	comp := map[string]int{}
	err = json.NewDecoder(resp.Body).Decode(&comp)
	return comp, err
}

type event struct {
	ID   int
	Time time.Time
	Type string
	Data interface{}
}

func (p *syncthingProcess) events() ([]event, error) {
	resp, err := p.get(fmt.Sprintf("/rest/events?since=%d", p.lastEvent))
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	var evs []event
	err = json.NewDecoder(resp.Body).Decode(&evs)
	if err != nil {
		return nil, err
	}
	p.lastEvent = evs[len(evs)-1].ID
	return evs, err
}

type versionResp struct {
	Version string
}

func (p *syncthingProcess) version() (string, error) {
	resp, err := p.get("/rest/version")
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	var v versionResp
	err = json.NewDecoder(resp.Body).Decode(&v)
	if err != nil {
		return "", err
	}
	return v.Version, nil
}