// Copyright 2014 The Gogs Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package repo

import (
	"container/list"
	"errors"
	"fmt"
	"path"
	"regexp"
	"strings"

	"github.com/Unknwon/com"

	"github.com/gogits/gogs/models"
	"github.com/gogits/gogs/modules/base"
	"github.com/gogits/gogs/modules/git"
	"github.com/gogits/gogs/modules/log"
	"github.com/gogits/gogs/modules/mailer"
	"github.com/gogits/gogs/modules/middleware"
	"github.com/gogits/gogs/modules/setting"
)

const (
	COMMITS      base.TplName = "repo/commits"
	DIFF         base.TplName = "repo/diff"
	COMMENT_FORM base.TplName = "repo/comment_form"
)

func RefCommits(ctx *middleware.Context) {
	switch {
	case len(ctx.Repo.TreeName) == 0:
		Commits(ctx)
	case ctx.Repo.TreeName == "search":
		SearchCommits(ctx)
	default:
		FileHistory(ctx)
	}
}

func RenderIssueLinks(oldCommits *list.List, repoLink string) *list.List {
	newCommits := list.New()
	for e := oldCommits.Front(); e != nil; e = e.Next() {
		c := e.Value.(*git.Commit)
		c.CommitMessage = c.CommitMessage
		newCommits.PushBack(c)
	}
	return newCommits
}

func Commits(ctx *middleware.Context) {
	ctx.Data["IsRepoToolbarCommits"] = true

	userName := ctx.Repo.Owner.Name
	repoName := ctx.Repo.Repository.Name

	brs, err := ctx.Repo.GitRepo.GetBranches()
	if err != nil {
		ctx.Handle(500, "GetBranches", err)
		return
	} else if len(brs) == 0 {
		ctx.Handle(404, "GetBranches", nil)
		return
	}

	commitsCount, err := ctx.Repo.Commit.CommitsCount()
	if err != nil {
		ctx.Handle(500, "GetCommitsCount", err)
		return
	}

	// Calculate and validate page number.
	page, _ := com.StrTo(ctx.Query("p")).Int()
	if page < 1 {
		page = 1
	}
	lastPage := page - 1
	if lastPage < 0 {
		lastPage = 0
	}
	nextPage := page + 1
	if page*50 > commitsCount {
		nextPage = 0
	}

	// Both `git log branchName` and `git log commitId` work.
	commits, err := ctx.Repo.Commit.CommitsByRange(page)
	if err != nil {
		ctx.Handle(500, "CommitsByRange", err)
		return
	}
	commits = RenderIssueLinks(commits, ctx.Repo.RepoLink)
	commits = models.ValidateCommitsWithEmails(commits)

	ctx.Data["Commits"] = commits
	ctx.Data["Username"] = userName
	ctx.Data["Reponame"] = repoName
	ctx.Data["CommitCount"] = commitsCount
	ctx.Data["LastPageNum"] = lastPage
	ctx.Data["NextPageNum"] = nextPage
	ctx.HTML(200, COMMITS)
}

func SearchCommits(ctx *middleware.Context) {
	ctx.Data["IsSearchPage"] = true
	ctx.Data["IsRepoToolbarCommits"] = true

	keyword := ctx.Query("q")
	if len(keyword) == 0 {
		ctx.Redirect(ctx.Repo.RepoLink + "/commits/" + ctx.Repo.BranchName)
		return
	}

	userName := ctx.Params(":username")
	repoName := ctx.Params(":reponame")

	brs, err := ctx.Repo.GitRepo.GetBranches()
	if err != nil {
		ctx.Handle(500, "GetBranches", err)
		return
	} else if len(brs) == 0 {
		ctx.Handle(404, "GetBranches", nil)
		return
	}

	commits, err := ctx.Repo.Commit.SearchCommits(keyword)
	if err != nil {
		ctx.Handle(500, "SearchCommits", err)
		return
	}
	commits = RenderIssueLinks(commits, ctx.Repo.RepoLink)
	commits = models.ValidateCommitsWithEmails(commits)

	ctx.Data["Keyword"] = keyword
	ctx.Data["Username"] = userName
	ctx.Data["Reponame"] = repoName
	ctx.Data["CommitCount"] = commits.Len()
	ctx.Data["Commits"] = commits
	ctx.HTML(200, COMMITS)
}

func FileHistory(ctx *middleware.Context) {
	ctx.Data["IsRepoToolbarCommits"] = true

	fileName := ctx.Repo.TreeName
	if len(fileName) == 0 {
		Commits(ctx)
		return
	}

	userName := ctx.Repo.Owner.Name
	repoName := ctx.Repo.Repository.Name
	branchName := ctx.Repo.BranchName

	brs, err := ctx.Repo.GitRepo.GetBranches()
	if err != nil {
		ctx.Handle(500, "GetBranches", err)
		return
	} else if len(brs) == 0 {
		ctx.Handle(404, "GetBranches", nil)
		return
	}

	commitsCount, err := ctx.Repo.GitRepo.FileCommitsCount(branchName, fileName)
	if err != nil {
		ctx.Handle(500, "repo.FileHistory(GetCommitsCount)", err)
		return
	} else if commitsCount == 0 {
		ctx.Handle(404, "repo.FileHistory", nil)
		return
	}

	// Calculate and validate page number.
	page := com.StrTo(ctx.Query("p")).MustInt()
	if page < 1 {
		page = 1
	}
	lastPage := page - 1
	if lastPage < 0 {
		lastPage = 0
	}
	nextPage := page + 1
	if nextPage*50 > commitsCount {
		nextPage = 0
	}

	commits, err := ctx.Repo.GitRepo.CommitsByFileAndRange(
		branchName, fileName, page)
	if err != nil {
		ctx.Handle(500, "repo.FileHistory(CommitsByRange)", err)
		return
	}
	commits = RenderIssueLinks(commits, ctx.Repo.RepoLink)
	commits = models.ValidateCommitsWithEmails(commits)

	ctx.Data["Commits"] = commits
	ctx.Data["Username"] = userName
	ctx.Data["Reponame"] = repoName
	ctx.Data["FileName"] = fileName
	ctx.Data["CommitCount"] = commitsCount
	ctx.Data["LastPageNum"] = lastPage
	ctx.Data["NextPageNum"] = nextPage
	ctx.HTML(200, COMMITS)
}

func Diff(ctx *middleware.Context) {
	ctx.Data["IsRepoToolbarCommits"] = true

	userName := ctx.Repo.Owner.Name
	repoName := ctx.Repo.Repository.Name
	commitId := ctx.Repo.CommitId

	commit := ctx.Repo.Commit
	commit.CommitMessage = commit.CommitMessage
	diff, err := models.GetDiffCommit(models.RepoPath(userName, repoName),
		commitId, setting.Git.MaxGitDiffLines)
	if err != nil {
		ctx.Handle(404, "GetDiffCommit", err)
		return
	}

	isImageFile := func(name string) bool {
		blob, err := ctx.Repo.Commit.GetBlobByPath(name)
		if err != nil {
			return false
		}

		dataRc, err := blob.Data()
		if err != nil {
			return false
		}
		buf := make([]byte, 1024)
		n, _ := dataRc.Read(buf)
		if n > 0 {
			buf = buf[:n]
		}
		_, isImage := base.IsImageFile(buf)
		return isImage
	}

	parents := make([]string, commit.ParentCount())
	for i := 0; i < commit.ParentCount(); i++ {
		sha, err := commit.ParentId(i)
		parents[i] = sha.String()
		if err != nil {
			ctx.Handle(404, "repo.Diff", err)
			return
		}
	}

	// Get comments.
	comments, err := models.GetCommitComments(commitId)
	if err != nil {
		ctx.Handle(500, "commit.GetDiffCommit(GetCommitComments): %v", err)
		return
	}

	// Get posters.
	commentsMap := make(map[string]map[int]models.Comment)
	for i := range comments {
		u, err := models.GetUserById(comments[i].PosterId)
		if err != nil {
			ctx.Handle(500, "issue.ViewIssue(GetUserById.2): %v", err)
			return
		}
		comments[i].Poster = u

		if comments[i].Type == models.COMMENT_TYPE_COMMENT {
			comments[i].Content = string(base.RenderMarkdown([]byte(comments[i].Content), ctx.Repo.RepoLink))
		}

		if _, ok := commentsMap[comments[i].Line]; !ok {
			commentsMap[comments[i].Line] = make(map[int]models.Comment)
		}
		commentsMap[comments[i].Line][i] = comments[i]
	}

	ctx.Data["Username"] = userName
	ctx.Data["Reponame"] = repoName
	ctx.Data["IsImageFile"] = isImageFile
	ctx.Data["Title"] = commit.Summary() + " · " + base.ShortSha(commitId)
	ctx.Data["Commit"] = commit
	ctx.Data["Author"] = models.ValidateCommitWithEmail(commit)
	ctx.Data["Diff"] = diff
	ctx.Data["Parents"] = parents
	ctx.Data["Comments"] = commentsMap
	ctx.Data["DiffNotAvailable"] = diff.NumFiles() == 0
	ctx.Data["SourcePath"] = setting.AppSubUrl + "/" + path.Join(userName, repoName, "src", commitId)
	if (commit.ParentCount() > 0) {
		ctx.Data["BeforeSourcePath"] = setting.AppSubUrl + "/" + path.Join(userName, repoName, "src", parents[0])
	}
	ctx.Data["RawPath"] = setting.AppSubUrl + "/" + path.Join(userName, repoName, "raw", commitId)
	ctx.HTML(200, DIFF)
}

func CompareDiff(ctx *middleware.Context) {
	ctx.Data["IsRepoToolbarCommits"] = true
	ctx.Data["IsDiffCompare"] = true
	userName := ctx.Repo.Owner.Name
	repoName := ctx.Repo.Repository.Name
	beforeCommitId := ctx.Params(":before")
	afterCommitId := ctx.Params(":after")

	commit, err := ctx.Repo.GitRepo.GetCommit(afterCommitId)
	if err != nil {
		ctx.Handle(404, "GetCommit", err)
		return
	}

	diff, err := models.GetDiffRange(models.RepoPath(userName, repoName), beforeCommitId,
		afterCommitId, setting.Git.MaxGitDiffLines)
	if err != nil {
		ctx.Handle(404, "GetDiffRange", err)
		return
	}

	isImageFile := func(name string) bool {
		blob, err := commit.GetBlobByPath(name)
		if err != nil {
			return false
		}

		dataRc, err := blob.Data()
		if err != nil {
			return false
		}
		buf := make([]byte, 1024)
		n, _ := dataRc.Read(buf)
		if n > 0 {
			buf = buf[:n]
		}
		_, isImage := base.IsImageFile(buf)
		return isImage
	}

	commits, err := commit.CommitsBeforeUntil(beforeCommitId)
	if err != nil {
		ctx.Handle(500, "CommitsBeforeUntil", err)
		return
	}
	commits = models.ValidateCommitsWithEmails(commits)

	ctx.Data["Commits"] = commits
	ctx.Data["CommitCount"] = commits.Len()
	ctx.Data["BeforeCommitId"] = beforeCommitId
	ctx.Data["AfterCommitId"] = afterCommitId
	ctx.Data["Username"] = userName
	ctx.Data["Reponame"] = repoName
	ctx.Data["IsImageFile"] = isImageFile
	ctx.Data["Title"] = "Comparing " + base.ShortSha(beforeCommitId) + "..." + base.ShortSha(afterCommitId) + " · " + userName + "/" + repoName
	ctx.Data["Commit"] = commit
	ctx.Data["Diff"] = diff
	ctx.Data["DiffNotAvailable"] = diff.NumFiles() == 0
	ctx.Data["SourcePath"] = setting.AppSubUrl + "/" + path.Join(userName, repoName, "src", afterCommitId)
	ctx.Data["BeforeSourcePath"] = setting.AppSubUrl + "/" + path.Join(userName, repoName, "src", beforeCommitId)
	ctx.Data["RawPath"] = setting.AppSubUrl + "/" + path.Join(userName, repoName, "raw", afterCommitId)
	ctx.HTML(200, DIFF)
}

func GetCommentForm(ctx *middleware.Context) {
	ctx.Data["Repo"] = ctx.Repo
	ctx.Data["Line"] = ctx.Query("line")
	ctx.Data["CommentId"] = ctx.Query("id")
	ctx.HTML(200, COMMENT_FORM)
}

func CreateCommitComment(ctx *middleware.Context) {

	send := func(status int, data interface{}, err error) {
		if err != nil {
			log.Error(4, "commit.Comment(?): %s", err)

			ctx.JSON(status, map[string]interface{}{
				"ok":     false,
				"status": status,
				"error":  err.Error(),
			})
		} else {
			ctx.JSON(status, map[string]interface{}{
				"ok":     true,
				"status": status,
				"data":   data,
			})
		}
	}
	var comment *models.Comment
	var err error

	commitId := ctx.ParamsEscape(":commitId")
	content := ctx.Query("content")
	if len(content) > 0 {
		switch ctx.Params(":action") {
		case "new":
			line := ctx.Query("line")
			lineRe, err := regexp.Compile("[a-zA-Z0-9]{40}[LR][0-9]+")
			if len(line) > 0 && !lineRe.MatchString(line) {
				err := errors.New("Something went wrong")
				send(200, err.Error(), err)
				return
			}
			if comment, err = models.CreateComment(ctx.User.Id, ctx.Repo.Repository.Id, 0, commitId, line, models.COMMENT_TYPE_COMMENT, content, nil); err != nil {
				send(500, nil, err)
				return
			}
			log.Trace("%s Comment created: %s", ctx.Req.RequestURI, commitId)
		case "edit":
			commentId := com.StrTo(ctx.Query("id")).MustInt64()
			comment, err = models.GetCommentById(commentId)
			if err != nil {
				send(500, nil, err)
				return
			}

			comment.Content = content
			if err = models.UpdateComment(comment); err != nil {
				send(500, nil, err)
				return
			}
			log.Trace("%s Comment updated: %v", ctx.Req.RequestURI, comment.Id)
		default:
			ctx.Handle(404, "commit.Comment", err)
			return
		}
	} else {
		err := errors.New(ctx.Locale.Tr("repo.commits.comment.required_field"))
		send(200, err.Error(), err)
		return
	}
	// Update mentions.
	ms := base.MentionPattern.FindAllString(comment.Content, -1)
	if len(ms) > 0 {
		for i := range ms {
			ms[i] = ms[i][1:]
		}
	}
	// Notify watchers.
	act := &models.Action{
		ActUserId:    ctx.User.Id,
		ActUserName:  ctx.User.LowerName,
		ActEmail:     ctx.User.Email,
		OpType:       models.COMMENT_COMMIT,
		Content:      fmt.Sprintf("%s|%s", commitId, strings.Split(content, "\n")[0]),
		RepoId:       ctx.Repo.Repository.Id,
		RepoUserName: ctx.Repo.Owner.LowerName,
		RepoName:     ctx.Repo.Repository.LowerName,
	}
	if err = models.NotifyWatchers(act); err != nil {
		send(500, nil, err)
		return
	}

	// Mail watchers and mentions.
	if setting.Service.EnableNotifyMail {
		comment.Content = content
		tos, err := mailer.SendCommentNotifyMail(ctx.User, ctx.Repo.Owner, ctx.Repo.Repository, comment)
		if err != nil {
			send(500, nil, err)
			return
		}

		tos = append(tos, ctx.User.LowerName)
		newTos := make([]string, 0, len(ms))
		for _, m := range ms {
			if com.IsSliceContainsStr(tos, m) {
				continue
			}

			newTos = append(newTos, m)
		}
		if err = mailer.SendCommentMentionMail(ctx.Render, ctx.User, ctx.Repo.Owner,
			ctx.Repo.Repository, comment, models.GetUserEmailsByNames(newTos)); err != nil {
			send(500, nil, err)
			return
		}
	}

	send(200, fmt.Sprintf("%s/commit/%s#comment-%d", ctx.Repo.RepoLink, commitId, comment.Id), nil)
}

func DeleteCommitComment(ctx *middleware.Context) {

	commentId := com.StrTo(ctx.Query("comment")).MustInt64()
	if err := models.DeleteComment(int64(commentId), ctx.User.Id); err != nil {
		ctx.JSON(200, map[string]interface{}{
			"ok":     false,
			"error":  err.Error(),
		})
		return
	}

	ctx.JSON(200, map[string]interface{}{
		"ok":     true,
		"data":  "ok",
	})
}