package gitw

import (
	"errors"

	"gitea.yves-biener.de/yves-biener/gitwarrior/internal/gitea"
	"gitea.yves-biener.de/yves-biener/gitwarrior/internal/taskwarrior"
)

type Project struct {
	server     gitea.Gitea
	repository gitea.Repository
	issues     []Issue
	milestones []gitea.Milestone
}

func NewProject(server gitea.Gitea, repository gitea.Repository) Project {
	return Project{
		server:     server,
		repository: repository,
	}
}

func (project *Project) Pull() error {
	if err := project.Fetch(); err != nil {
		return err
	}
	if err := project.merge(); err != nil {
		return err
	}
	return nil
}

func (project *Project) Fetch() error {
	comments, err := project.server.GetComments(project.repository)
	if err != nil {
		return err
	}
	issues, err := project.server.GetIssues(project.repository)
	if err != nil {
		return err
	}
	project.milestones, err = project.server.GetMilestones(project.repository)
	if err != nil {
		return err
	}
	for _, issue := range issues {
		var issue_comments []gitea.Comment
		for _, comment := range comments {
			if comment.Issue_url == issue.Html_url {
				issue_comments = append(issue_comments, comment)
			}
		}
		project.issues = append(project.issues, Issue{
			issue:    issue,
			comments: issue_comments,
		})
	}
	return nil
}

func (project *Project) merge() error {
	// TODO: run merge to update the local taskwarrior tasks into the state of the
	// issues and milestones
	return nil
}

type Issue struct {
	issue    gitea.Issue
	comments []gitea.Comment
}

func (i *Issue) into() (taskwarrior.Task, error) {
	// TODO: identify if issue is already an existing task
	var filter taskwarrior.Filter
	filter.IncludeGitId(i.issue.Id)
	filter.IncludeGitType(taskwarrior.ISSUE)
	tasks, err := taskwarrior.GetTasks(filter)
	if err != nil {
		// this means that a task for this issue does not exist yet
		return taskwarrior.NewTask(
			i.issue.Title,
			i.issue.Repository.Name,
			i.issue.Id,
			taskwarrior.ISSUE,
			i.issue.Labels...,
		), nil
	} else {
		// this means that a task exists and it needs to be merged
		if len(tasks) != 1 {
			return taskwarrior.Task{}, errors.New("Did not find exactly one task for a given issue.Id")
		}
		return i.merge(tasks[0]), nil
	}
}

func (i *Issue) merge(task taskwarrior.Task) taskwarrior.Task {
	// TODO: issue values into task:
	// - is the issue more recent than the task?
	// - apply changes into task
	// - in case of merge conflicts ask user for corresponding action:
	//     1. use theirs
	//     2. use mine
	//     3. use provided value
	return task
}