package vcs

import (
	"net/url"
	"regexp"
	"strings"
	"time"

	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing/object"
	"gitlab.com/tozd/go/errors"
)

const hashLength = 7

type Author struct {
	Name  string
	Email string
}

type Commit struct {
	repo        *Repository
	ShortHash   string
	Hash        string
	Message     string
	Summary     string
	Description string
	Author      Author
	Date        time.Time
	Link        *url.URL
}

func (r *Repository) makeCommitURL(hash string) *url.URL {
	return r.remoteURL.JoinPath("commit", hash)
}

func (r *Repository) GetFileLog(filename string) ([]*Commit, errors.E) {
	var fl object.CommitIter
	var err error
	fl, err = r.repo.Log(&git.LogOptions{
		Order:    git.LogOrderCommitterTime,
		FileName: &filename,
	})
	if err != nil {
		return nil, errors.WithMessagef(err, "could not get git log for file %s", filename)
	}

	defer fl.Close()
	cs := make([]*Commit, 0)
	err = fl.ForEach(func(c *object.Commit) error {
		summary, description, _ := strings.Cut(c.Message, "\n")
		cs = append(cs, &Commit{
			repo:        r,
			ShortHash:   c.Hash.String()[:hashLength],
			Hash:        c.Hash.String(),
			Message:     c.Message,
			Summary:     summary,
			Description: cleanupDescription(description),
			Author: Author{
				Name:  c.Author.Name,
				Email: c.Author.Email,
			},
			Date: c.Author.When,
			Link: r.makeCommitURL(c.Hash.String()),
		})

		return nil
	})
	if err != nil {
		return nil, errors.WithMessagef(err, "could not iterate over commits for file %s", filename)
	}

	return cs, nil
}

var rewrap = regexp.MustCompile(`\r?\n(\w)`)

func cleanupDescription(description string) string {
	return strings.TrimSpace(rewrap.ReplaceAllString(description, " $1"))
}

func (c *Commit) MakeFileLink(filename string) *url.URL {
	return c.repo.remoteURL.JoinPath("blob", c.Hash, filename)
}