package git_test

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/gitleaks/go-gitdiff/gitdiff"
	"github.com/zricethezav/gitleaks/v8/git"
)

const repoBasePath = "../testdata/repos/"
const expectPath = "../testdata/expected/"

func TestGitLog(t *testing.T) {
	tests := []struct {
		source   string
		logOpts  string
		expected string
	}{
		{
			source:   filepath.Join(repoBasePath, "small"),
			expected: filepath.Join(expectPath, "git", "small.txt"),
		},
		{
			source:   filepath.Join(repoBasePath, "small"),
			expected: filepath.Join(expectPath, "git", "small-branch-foo.txt"),
			logOpts:  "--all foo...",
		},
	}

	err := moveDotGit("dotGit", ".git")
	if err != nil {
		t.Fatal(err)
	}
	defer moveDotGit(".git", "dotGit")

	for _, tt := range tests {
		files, err := git.GitLog(tt.source, tt.logOpts)
		if err != nil {
			t.Error(err)
		}

		var diffSb strings.Builder
		for f := range files {
			for _, tf := range f.TextFragments {
				diffSb.WriteString(tf.Raw(gitdiff.OpAdd))
			}
		}

		expectedBytes, err := os.ReadFile(tt.expected)
		if err != nil {
			t.Error(err)
		}
		expected := string(expectedBytes)
		if expected != diffSb.String() {
			// write string builder to .got file using os.Create
			err = os.WriteFile(strings.Replace(tt.expected, ".txt", ".got.txt", 1), []byte(diffSb.String()), 0644)
			if err != nil {
				t.Error(err)
			}
			t.Error("expected: ", expected, "got: ", diffSb.String())
		}
	}
}

func TestGitDiff(t *testing.T) {
	tests := []struct {
		source    string
		expected  string
		additions string
		target    string
	}{
		{
			source:    filepath.Join(repoBasePath, "small"),
			expected:  "this line is added\nand another one",
			additions: "this line is added\nand another one",
			target:    filepath.Join(repoBasePath, "small", "main.go"),
		},
	}

	err := moveDotGit("dotGit", ".git")
	if err != nil {
		t.Fatal(err)
	}
	defer moveDotGit(".git", "dotGit")

	for _, tt := range tests {
		noChanges, err := os.ReadFile(tt.target)
		if err != nil {
			t.Error(err)
		}
		err = os.WriteFile(tt.target, []byte(tt.additions), 0644)
		if err != nil {
			restore(tt.target, noChanges, t)
			t.Error(err)
		}

		files, err := git.GitDiff(tt.source, false)
		if err != nil {
			restore(tt.target, noChanges, t)
			t.Error(err)
		}

		for f := range files {
			sb := strings.Builder{}
			for _, tf := range f.TextFragments {
				sb.WriteString(tf.Raw(gitdiff.OpAdd))
			}
			if sb.String() != tt.expected {
				restore(tt.target, noChanges, t)
				t.Error("expected: ", tt.expected, "got: ", sb.String())
			}
		}
		restore(tt.target, noChanges, t)
	}
}

func restore(path string, data []byte, t *testing.T) {
	err := os.WriteFile(path, data, 0644)
	if err != nil {
		t.Fatal(err)
	}
}

func moveDotGit(from, to string) error {
	repoDirs, err := os.ReadDir("../testdata/repos")
	if err != nil {
		return err
	}
	for _, dir := range repoDirs {
		if to == ".git" {
			_, err := os.Stat(fmt.Sprintf("%s/%s/%s", repoBasePath, dir.Name(), "dotGit"))
			if os.IsNotExist(err) {
				// dont want to delete the only copy of .git accidentally
				continue
			}
			os.RemoveAll(fmt.Sprintf("%s/%s/%s", repoBasePath, dir.Name(), ".git"))
		}
		if !dir.IsDir() {
			continue
		}
		_, err := os.Stat(fmt.Sprintf("%s/%s/%s", repoBasePath, dir.Name(), from))
		if os.IsNotExist(err) {
			continue
		}

		err = os.Rename(fmt.Sprintf("%s/%s/%s", repoBasePath, dir.Name(), from),
			fmt.Sprintf("%s/%s/%s", repoBasePath, dir.Name(), to))
		if err != nil {
			return err
		}
	}
	return nil
}