// 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 (
	"errors"
	"fmt"

	"code.gitea.io/git"
	"code.gitea.io/gitea/models"
	"code.gitea.io/gitea/modules/auth"
	"code.gitea.io/gitea/modules/base"
	"code.gitea.io/gitea/modules/context"
	"code.gitea.io/gitea/modules/log"
	"code.gitea.io/gitea/modules/markdown"
	"github.com/Unknwon/paginater"
)

const (
	tplReleases   base.TplName = "repo/release/list"
	tplReleaseNew base.TplName = "repo/release/new"
)

// calReleaseNumCommitsBehind calculates given release has how many commits behind release target.
func calReleaseNumCommitsBehind(repoCtx *context.Repository, release *models.Release, countCache map[string]int64) error {
	// Fast return if release target is same as default branch.
	if repoCtx.BranchName == release.Target {
		release.NumCommitsBehind = repoCtx.CommitsCount - release.NumCommits
		return nil
	}

	// Get count if not exists
	if _, ok := countCache[release.Target]; !ok {
		if repoCtx.GitRepo.IsBranchExist(release.Target) {
			commit, err := repoCtx.GitRepo.GetBranchCommit(release.Target)
			if err != nil {
				return fmt.Errorf("GetBranchCommit: %v", err)
			}
			countCache[release.Target], err = commit.CommitsCount()
			if err != nil {
				return fmt.Errorf("CommitsCount: %v", err)
			}
		} else {
			// Use NumCommits of the newest release on that target
			countCache[release.Target] = release.NumCommits
		}
	}
	release.NumCommitsBehind = countCache[release.Target] - release.NumCommits
	return nil
}

// Releases render releases list page
func Releases(ctx *context.Context) {
	ctx.Data["Title"] = ctx.Tr("repo.release.releases")
	ctx.Data["PageIsReleaseList"] = true

	page := ctx.QueryInt("page")
	if page <= 1 {
		page = 1
	}
	limit := ctx.QueryInt("limit")
	if limit <= 0 {
		limit = 10
	}

	rawTags, err := ctx.Repo.GitRepo.GetTagInfos(git.TagOption{})
	if err != nil {
		ctx.Handle(500, "GetTags", err)
		return
	}

	if len(rawTags) <= (page-1)*limit {
		ctx.Handle(500, "Releases", errors.New("no more pages"))
		return
	}

	var tags []*git.Tag
	if page*limit > len(rawTags) {
		tags = rawTags[(page-1)*limit:]
	} else {
		tags = rawTags[(page-1)*limit : page*limit]
	}

	var tagNames []string
	for _, t := range tags {
		tagNames = append(tagNames, t.Name)
	}

	releases, err := models.GetReleasesByRepoIDAndNames(ctx.Repo.Repository.ID, tagNames)
	if err != nil {
		ctx.Handle(500, "GetReleasesByRepoIDAndNames", err)
		return
	}

	// Temproray cache commits count of used branches to speed up.
	countCache := make(map[string]int64)
	var cacheUsers = make(map[int64]*models.User)
	var ok bool
	releaseTags := make([]*models.Release, len(tags))
	for i, rawTag := range tags {
		for _, r := range releases {
			if r.IsDraft && !ctx.Repo.IsOwner() {
				continue
			}
			if r.TagName == rawTag.Name {
				if r.Publisher, ok = cacheUsers[r.PublisherID]; !ok {
					r.Publisher, err = models.GetUserByID(r.PublisherID)
					if err != nil {
						if models.IsErrUserNotExist(err) {
							r.Publisher = models.NewGhostUser()
						} else {
							ctx.Handle(500, "GetUserByID", err)
							return
						}
					}
					cacheUsers[r.PublisherID] = r.Publisher
				}

				if err := calReleaseNumCommitsBehind(ctx.Repo, r, countCache); err != nil {
					ctx.Handle(500, "calReleaseNumCommitsBehind", err)
					return
				}

				r.Note = markdown.RenderString(r.Note, ctx.Repo.RepoLink, ctx.Repo.Repository.ComposeMetas())
				releaseTags[i] = r
				break
			}
		}

		if releaseTags[i] == nil {
			releaseTags[i] = &models.Release{
				Title:   rawTag.Name,
				TagName: rawTag.Name,
				Sha1:    rawTag.Object.String(),
				Note:    rawTag.Message,
			}

			releaseTags[i].NumCommits, err = git.CommitsCount(ctx.Repo.GitRepo.Path, rawTag.Object.String())
			if err != nil {
				ctx.Handle(500, "CommitsCount", err)
				return
			}
			releaseTags[i].NumCommitsBehind = ctx.Repo.CommitsCount - releaseTags[i].NumCommits
		}
	}

	pager := paginater.New(ctx.Repo.Repository.NumTags, limit, page, 5)
	ctx.Data["Page"] = pager
	ctx.Data["Releases"] = releaseTags
	ctx.HTML(200, tplReleases)
}

// NewRelease render creating release page
func NewRelease(ctx *context.Context) {
	ctx.Data["Title"] = ctx.Tr("repo.release.new_release")
	ctx.Data["PageIsReleaseList"] = true
	ctx.Data["tag_target"] = ctx.Repo.Repository.DefaultBranch
	ctx.HTML(200, tplReleaseNew)
}

// NewReleasePost response for creating a release
func NewReleasePost(ctx *context.Context, form auth.NewReleaseForm) {
	ctx.Data["Title"] = ctx.Tr("repo.release.new_release")
	ctx.Data["PageIsReleaseList"] = true

	if ctx.HasError() {
		ctx.HTML(200, tplReleaseNew)
		return
	}

	if !ctx.Repo.GitRepo.IsBranchExist(form.Target) {
		ctx.RenderWithErr(ctx.Tr("form.target_branch_not_exist"), tplReleaseNew, &form)
		return
	}

	var tagCreatedUnix int64
	tag, err := ctx.Repo.GitRepo.GetTag(form.TagName)
	if err == nil {
		commit, err := tag.Commit()
		if err == nil {
			tagCreatedUnix = commit.Author.When.Unix()
		}
	}

	commit, err := ctx.Repo.GitRepo.GetBranchCommit(form.Target)
	if err != nil {
		ctx.Handle(500, "GetBranchCommit", err)
		return
	}

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

	rel := &models.Release{
		RepoID:       ctx.Repo.Repository.ID,
		PublisherID:  ctx.User.ID,
		Title:        form.Title,
		TagName:      form.TagName,
		Target:       form.Target,
		Sha1:         commit.ID.String(),
		NumCommits:   commitsCount,
		Note:         form.Content,
		IsDraft:      len(form.Draft) > 0,
		IsPrerelease: form.Prerelease,
		CreatedUnix:  tagCreatedUnix,
	}

	if err = models.CreateRelease(ctx.Repo.GitRepo, rel); err != nil {
		ctx.Data["Err_TagName"] = true
		switch {
		case models.IsErrReleaseAlreadyExist(err):
			ctx.RenderWithErr(ctx.Tr("repo.release.tag_name_already_exist"), tplReleaseNew, &form)
		case models.IsErrInvalidTagName(err):
			ctx.RenderWithErr(ctx.Tr("repo.release.tag_name_invalid"), tplReleaseNew, &form)
		default:
			ctx.Handle(500, "CreateRelease", err)
		}
		return
	}
	log.Trace("Release created: %s/%s:%s", ctx.User.LowerName, ctx.Repo.Repository.Name, form.TagName)

	ctx.Redirect(ctx.Repo.RepoLink + "/releases")
}

// EditRelease render release edit page
func EditRelease(ctx *context.Context) {
	ctx.Data["Title"] = ctx.Tr("repo.release.edit_release")
	ctx.Data["PageIsReleaseList"] = true
	ctx.Data["PageIsEditRelease"] = true

	tagName := ctx.Params("*")
	rel, err := models.GetRelease(ctx.Repo.Repository.ID, tagName)
	if err != nil {
		if models.IsErrReleaseNotExist(err) {
			ctx.Handle(404, "GetRelease", err)
		} else {
			ctx.Handle(500, "GetRelease", err)
		}
		return
	}
	ctx.Data["ID"] = rel.ID
	ctx.Data["tag_name"] = rel.TagName
	ctx.Data["tag_target"] = rel.Target
	ctx.Data["title"] = rel.Title
	ctx.Data["content"] = rel.Note
	ctx.Data["prerelease"] = rel.IsPrerelease
	ctx.Data["IsDraft"] = rel.IsDraft

	ctx.HTML(200, tplReleaseNew)
}

// EditReleasePost response for edit release
func EditReleasePost(ctx *context.Context, form auth.EditReleaseForm) {
	ctx.Data["Title"] = ctx.Tr("repo.release.edit_release")
	ctx.Data["PageIsReleaseList"] = true
	ctx.Data["PageIsEditRelease"] = true

	tagName := ctx.Params("*")
	rel, err := models.GetRelease(ctx.Repo.Repository.ID, tagName)
	if err != nil {
		if models.IsErrReleaseNotExist(err) {
			ctx.Handle(404, "GetRelease", err)
		} else {
			ctx.Handle(500, "GetRelease", err)
		}
		return
	}
	ctx.Data["tag_name"] = rel.TagName
	ctx.Data["tag_target"] = rel.Target
	ctx.Data["title"] = rel.Title
	ctx.Data["content"] = rel.Note
	ctx.Data["prerelease"] = rel.IsPrerelease

	if ctx.HasError() {
		ctx.HTML(200, tplReleaseNew)
		return
	}

	rel.Title = form.Title
	rel.Note = form.Content
	rel.IsDraft = len(form.Draft) > 0
	rel.IsPrerelease = form.Prerelease
	if err = models.UpdateRelease(ctx.Repo.GitRepo, rel); err != nil {
		ctx.Handle(500, "UpdateRelease", err)
		return
	}
	ctx.Redirect(ctx.Repo.RepoLink + "/releases")
}

// DeleteRelease delete a release
func DeleteRelease(ctx *context.Context) {
	delTag := ctx.QueryBool("delTag")
	if err := models.DeleteReleaseByID(ctx.QueryInt64("id"), ctx.User, delTag); err != nil {
		ctx.Flash.Error("DeleteReleaseByID: " + err.Error())
	} else {
		ctx.Flash.Success(ctx.Tr("repo.release.deletion_success"))
	}

	ctx.JSON(200, map[string]interface{}{
		"redirect": ctx.Repo.RepoLink + "/releases",
	})
}