package types

import (
	"github.com/bluekeyes/go-gitdiff/gitdiff"
	"github.com/go-git/go-git/v5/plumbing/object"
)

type TextFragment struct {
	Header string         `json:"comment"`
	Lines  []gitdiff.Line `json:"lines"`
}

type Diff struct {
	Name struct {
		Old string `json:"old"`
		New string `json:"new"`
	} `json:"name"`
	TextFragments []gitdiff.TextFragment `json:"text_fragments"`
	IsBinary      bool                   `json:"is_binary"`
	IsNew         bool                   `json:"is_new"`
	IsDelete      bool                   `json:"is_delete"`
	IsCopy        bool                   `json:"is_copy"`
	IsRename      bool                   `json:"is_rename"`
}

type DiffStat struct {
	Insertions int64
	Deletions  int64
}

func (d *Diff) Stats() DiffStat {
	var stats DiffStat
	for _, f := range d.TextFragments {
		stats.Insertions += f.LinesAdded
		stats.Deletions += f.LinesDeleted
	}
	return stats
}

// A nicer git diff representation.
type NiceDiff struct {
	Commit struct {
		Message      string           `json:"message"`
		Author       object.Signature `json:"author"`
		This         string           `json:"this"`
		Parent       string           `json:"parent"`
		PGPSignature string           `json:"pgp_signature"`
		Committer    object.Signature `json:"committer"`
		Tree         string           `json:"tree"`
		ChangedId    string           `json:"change_id"`
	} `json:"commit"`
	Stat struct {
		FilesChanged int `json:"files_changed"`
		Insertions   int `json:"insertions"`
		Deletions    int `json:"deletions"`
	} `json:"stat"`
	Diff []Diff `json:"diff"`
}

type DiffTree struct {
	Rev1  string          `json:"rev1"`
	Rev2  string          `json:"rev2"`
	Patch string          `json:"patch"`
	Diff  []*gitdiff.File `json:"diff"`
}

func (d *NiceDiff) ChangedFiles() []string {
	files := make([]string, len(d.Diff))

	for i, f := range d.Diff {
		if f.IsDelete {
			files[i] = f.Name.Old
		} else {
			files[i] = f.Name.New
		}
	}

	return files
}

// ObjectCommitToNiceDiff is a compatibility function to convert a
// commit object into a NiceDiff structure.
func ObjectCommitToNiceDiff(c *object.Commit) NiceDiff {
	var niceDiff NiceDiff

	// set commit information
	niceDiff.Commit.Message = c.Message
	niceDiff.Commit.Author = c.Author
	niceDiff.Commit.This = c.Hash.String()
	niceDiff.Commit.Committer = c.Committer
	niceDiff.Commit.Tree = c.TreeHash.String()
	niceDiff.Commit.PGPSignature = c.PGPSignature

	changeId, ok := c.ExtraHeaders["change-id"]
	if ok {
		niceDiff.Commit.ChangedId = string(changeId)
	}

	// set parent hash if available
	if len(c.ParentHashes) > 0 {
		niceDiff.Commit.Parent = c.ParentHashes[0].String()
	}

	// XXX: Stats and Diff fields are typically populated
	// after fetching the actual diff information, which isn't
	// directly available in the commit object itself.

	return niceDiff
}