// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package issues

import (
	"context"
	"fmt"

	"code.gitea.io/gitea/models/db"
	project_model "code.gitea.io/gitea/models/project"
	user_model "code.gitea.io/gitea/models/user"
)

// LoadProject load the project the issue was assigned to
func (issue *Issue) LoadProject(ctx context.Context) (err error) {
	if issue.Project == nil {
		var p project_model.Project
		has, err := db.GetEngine(ctx).Table("project").
			Join("INNER", "project_issue", "project.id=project_issue.project_id").
			Where("project_issue.issue_id = ?", issue.ID).Get(&p)
		if err != nil {
			return err
		} else if has {
			issue.Project = &p
		}
	}
	return err
}

func (issue *Issue) projectID(ctx context.Context) int64 {
	var ip project_model.ProjectIssue
	has, err := db.GetEngine(ctx).Where("issue_id=?", issue.ID).Get(&ip)
	if err != nil || !has {
		return 0
	}
	return ip.ProjectID
}

// ProjectBoardID return project board id if issue was assigned to one
func (issue *Issue) ProjectBoardID(ctx context.Context) int64 {
	var ip project_model.ProjectIssue
	has, err := db.GetEngine(ctx).Where("issue_id=?", issue.ID).Get(&ip)
	if err != nil || !has {
		return 0
	}
	return ip.ProjectBoardID
}

// LoadIssuesFromBoard load issues assigned to this board
func LoadIssuesFromBoard(ctx context.Context, b *project_model.Board) (IssueList, error) {
	issueList, err := Issues(ctx, &IssuesOptions{
		ProjectBoardID: b.ID,
		ProjectID:      b.ProjectID,
		SortType:       "project-column-sorting",
	})
	if err != nil {
		return nil, err
	}

	if b.Default {
		issues, err := Issues(ctx, &IssuesOptions{
			ProjectBoardID: db.NoConditionID,
			ProjectID:      b.ProjectID,
			SortType:       "project-column-sorting",
		})
		if err != nil {
			return nil, err
		}
		issueList = append(issueList, issues...)
	}

	if err := issueList.LoadComments(ctx); err != nil {
		return nil, err
	}

	return issueList, nil
}

// LoadIssuesFromBoardList load issues assigned to the boards
func LoadIssuesFromBoardList(ctx context.Context, bs project_model.BoardList) (map[int64]IssueList, error) {
	issuesMap := make(map[int64]IssueList, len(bs))
	for i := range bs {
		il, err := LoadIssuesFromBoard(ctx, bs[i])
		if err != nil {
			return nil, err
		}
		issuesMap[bs[i].ID] = il
	}
	return issuesMap, nil
}

// ChangeProjectAssign changes the project associated with an issue, if newProjectID is 0, the issue is removed from the project
func ChangeProjectAssign(ctx context.Context, issue *Issue, doer *user_model.User, newProjectID, newColumnID int64) error {
	return db.WithTx(ctx, func(ctx context.Context) error {
		return addUpdateIssueProject(ctx, issue, doer, newProjectID, newColumnID)
	})
}

// addUpdateIssueProject adds or updates the project the default column associated with an issue
// If newProjectID is 0, the issue is removed from the project
func addUpdateIssueProject(ctx context.Context, issue *Issue, doer *user_model.User, newProjectID, newColumnID int64) error {
	oldProjectID := issue.projectID(ctx)

	if err := issue.LoadRepo(ctx); err != nil {
		return err
	}

	// Only check if we add a new project and not remove it.
	if newProjectID > 0 {
		newProject, err := project_model.GetProjectByID(ctx, newProjectID)
		if err != nil {
			return err
		}
		if newProject.RepoID != issue.RepoID && newProject.OwnerID != issue.Repo.OwnerID {
			return fmt.Errorf("issue's repository is not the same as project's repository")
		}
	}

	if _, err := db.GetEngine(ctx).Where("project_issue.issue_id=?", issue.ID).Delete(&project_model.ProjectIssue{}); err != nil {
		return err
	}

	if oldProjectID > 0 || newProjectID > 0 {
		if _, err := CreateComment(ctx, &CreateCommentOptions{
			Type:         CommentTypeProject,
			Doer:         doer,
			Repo:         issue.Repo,
			Issue:        issue,
			OldProjectID: oldProjectID,
			ProjectID:    newProjectID,
		}); err != nil {
			return err
		}
	}
	if newProjectID == 0 || newColumnID == 0 {
		return nil
	}

	var maxSorting int64
	if _, err := db.GetEngine(ctx).Select("Max(sorting)").Table("project_issue").
		Where("project_id=?", newProjectID).
		And("project_board_id=?", newColumnID).
		Get(&maxSorting); err != nil {
		return err
	}
	if maxSorting > 0 {
		maxSorting++
	}

	return db.Insert(ctx, &project_model.ProjectIssue{
		IssueID:        issue.ID,
		ProjectID:      newProjectID,
		ProjectBoardID: newColumnID,
		Sorting:        maxSorting,
	})
}