// Copyright (C) 2014 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at http://mozilla.org/MPL/2.0/.

// +build integration

package integration

import (
	"fmt"
	"log"
	"os"
	"testing"
	"time"

	"github.com/syncthing/protocol"
	"github.com/syncthing/syncthing/internal/config"
)

func TestSyncClusterWithoutVersioning(t *testing.T) {
	// Use no versioning
	id, _ := protocol.DeviceIDFromString(id2)
	cfg, _ := config.Load("h2/config.xml", id)
	fld := cfg.Folders()["default"]
	fld.Versioning = config.VersioningConfiguration{}
	cfg.SetFolder(fld)
	cfg.Save()

	testSyncCluster(t)
}

func TestSyncClusterSimpleVersioning(t *testing.T) {
	// Use simple versioning
	id, _ := protocol.DeviceIDFromString(id2)
	cfg, _ := config.Load("h2/config.xml", id)
	fld := cfg.Folders()["default"]
	fld.Versioning = config.VersioningConfiguration{
		Type:   "simple",
		Params: map[string]string{"keep": "5"},
	}
	cfg.SetFolder(fld)
	cfg.Save()

	testSyncCluster(t)
}

func TestSyncClusterStaggeredVersioning(t *testing.T) {
	// Use staggered versioning
	id, _ := protocol.DeviceIDFromString(id2)
	cfg, _ := config.Load("h2/config.xml", id)
	fld := cfg.Folders()["default"]
	fld.Versioning = config.VersioningConfiguration{
		Type: "staggered",
	}
	cfg.SetFolder(fld)
	cfg.Save()

	testSyncCluster(t)
}

func testSyncCluster(t *testing.T) {
	/*

		This tests syncing files back and forth between three cluster members.
		Their configs are in h1, h2 and h3. The folder "default" is shared
		between all and stored in s1, s2 and s3 respectively.

		Another folder is shared between 1 and 2 only, in s12-1 and s12-2. A
		third folders is shared between 2 and 3, in s23-2 and s23-3.

	*/
	log.Println("Cleaning...")
	err := removeAll("s1", "s12-1",
		"s2", "s12-2", "s23-2",
		"s3", "s23-3",
		"h1/index", "h2/index", "h3/index")
	if err != nil {
		t.Fatal(err)
	}

	// Create initial folder contents. All three devices have stuff in
	// "default", which should be merged. The other two folders are initially
	// empty on one side.

	log.Println("Generating files...")

	err = generateFiles("s1", 1000, 21, "../LICENSE")
	if err != nil {
		t.Fatal(err)
	}
	err = generateFiles("s12-1", 1000, 21, "../LICENSE")
	if err != nil {
		t.Fatal(err)
	}

	// We'll use this file for appending data without modifying the time stamp.
	fd, err := os.Create("s1/test-appendfile")
	if err != nil {
		t.Fatal(err)
	}
	_, err = fd.WriteString("hello\n")
	if err != nil {
		t.Fatal(err)
	}
	err = fd.Close()
	if err != nil {
		t.Fatal(err)
	}

	err = generateFiles("s2", 1000, 21, "../LICENSE")
	if err != nil {
		t.Fatal(err)
	}
	err = generateFiles("s23-2", 1000, 21, "../LICENSE")
	if err != nil {
		t.Fatal(err)
	}

	err = generateFiles("s3", 1000, 21, "../LICENSE")
	if err != nil {
		t.Fatal(err)
	}

	// Prepare the expected state of folders after the sync
	c1, err := directoryContents("s1")
	if err != nil {
		t.Fatal(err)
	}
	c2, err := directoryContents("s2")
	if err != nil {
		t.Fatal(err)
	}
	c3, err := directoryContents("s3")
	if err != nil {
		t.Fatal(err)
	}
	e1 := mergeDirectoryContents(c1, c2, c3)
	e2, err := directoryContents("s12-1")
	if err != nil {
		t.Fatal(err)
	}
	e3, err := directoryContents("s23-2")
	if err != nil {
		t.Fatal(err)
	}
	expected := [][]fileInfo{e1, e2, e3}

	// Start the syncers
	p, err := scStartProcesses()
	if err != nil {
		t.Fatal(err)
	}
	defer func() {
		for i := range p {
			p[i].stop()
		}
	}()

	for count := 0; count < 5; count++ {
		log.Println("Forcing rescan...")

		// Force rescan of folders
		for i := range p {
			p[i].post("/rest/scan?folder=default", nil)
			if i < 3 {
				p[i].post("/rest/scan?folder=s12", nil)
			}
			if i > 1 {
				p[i].post("/rest/scan?folder=s23", nil)
			}
		}

		// Sync stuff and verify it looks right
		err = scSyncAndCompare(p, expected)
		if err != nil {
			t.Error(err)
			break
		}

		log.Println("Altering...")

		// Alter the source files for another round
		err = alterFiles("s1")
		if err != nil {
			t.Error(err)
			break
		}
		err = alterFiles("s12-1")
		if err != nil {
			t.Error(err)
			break
		}
		err = alterFiles("s23-2")
		if err != nil {
			t.Error(err)
			break
		}

		// Alter the "test-appendfile" without changing it's modification time. Sneaky!
		fi, err := os.Stat("s1/test-appendfile")
		if err != nil {
			t.Fatal(err)
		}
		fd, err := os.OpenFile("s1/test-appendfile", os.O_APPEND|os.O_WRONLY, 0644)
		if err != nil {
			t.Fatal(err)
		}
		_, err = fd.Seek(0, os.SEEK_END)
		if err != nil {
			t.Fatal(err)
		}
		_, err = fd.WriteString("more data\n")
		if err != nil {
			t.Fatal(err)
		}
		err = fd.Close()
		if err != nil {
			t.Fatal(err)
		}
		err = os.Chtimes("s1/test-appendfile", fi.ModTime(), fi.ModTime())
		if err != nil {
			t.Fatal(err)
		}

		// Prepare the expected state of folders after the sync
		e1, err = directoryContents("s1")
		if err != nil {
			t.Fatal(err)
		}
		e2, err = directoryContents("s12-1")
		if err != nil {
			t.Fatal(err)
		}
		e3, err = directoryContents("s23-2")
		if err != nil {
			t.Fatal(err)
		}
		expected = [][]fileInfo{e1, e2, e3}
	}
}

func scStartProcesses() ([]syncthingProcess, error) {
	p := make([]syncthingProcess, 3)

	p[0] = syncthingProcess{ // id1
		instance: "1",
		argv:     []string{"-home", "h1"},
		port:     8081,
		apiKey:   apiKey,
	}
	err := p[0].start()
	if err != nil {
		return nil, err
	}

	p[1] = syncthingProcess{ // id2
		instance: "2",
		argv:     []string{"-home", "h2"},
		port:     8082,
		apiKey:   apiKey,
	}
	err = p[1].start()
	if err != nil {
		_ = p[0].stop()
		return nil, err
	}

	p[2] = syncthingProcess{ // id3
		instance: "3",
		argv:     []string{"-home", "h3"},
		port:     8083,
		apiKey:   apiKey,
	}
	err = p[2].start()
	if err != nil {
		_ = p[0].stop()
		_ = p[1].stop()
		return nil, err
	}

	return p, nil
}

func scSyncAndCompare(p []syncthingProcess, expected [][]fileInfo) error {
	ids := []string{id1, id2, id3}

	log.Println("Syncing...")

mainLoop:
	for {
		time.Sleep(2500 * time.Millisecond)

		for i := range p {
			comp, err := p[i].peerCompletion()
			if err != nil {
				if isTimeout(err) {
					continue mainLoop
				}
				return err
			}

			for id, pct := range comp {
				if id == ids[i] {
					// Don't check for self, which will be 0%
					continue
				}
				if pct != 100 {
					log.Printf("%s not done yet: %d%%", id, pct)
					continue mainLoop
				}
			}
		}

		break
	}

	log.Println("Checking...")

	for _, dir := range []string{"s1", "s2", "s3"} {
		actual, err := directoryContents(dir)
		if err != nil {
			return err
		}
		if err := compareDirectoryContents(actual, expected[0]); err != nil {
			return fmt.Errorf("%s: %v", dir, err)
		}
	}

	for _, dir := range []string{"s12-1", "s12-2"} {
		actual, err := directoryContents(dir)
		if err != nil {
			return err
		}
		if err := compareDirectoryContents(actual, expected[1]); err != nil {
			return fmt.Errorf("%s: %v", dir, err)
		}
	}

	for _, dir := range []string{"s23-2", "s23-3"} {
		actual, err := directoryContents(dir)
		if err != nil {
			return err
		}
		if err := compareDirectoryContents(actual, expected[2]); err != nil {
			return fmt.Errorf("%s: %v", dir, err)
		}
	}

	return nil
}