package tools

import (
	"context"
	"encoding/json"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
)

func requireGit(t *testing.T) {
	t.Helper()
	if _, err := exec.LookPath("git"); err != nil {
		t.Skip("git not installed")
	}
}

func runGitForTest(t *testing.T, dir string, args ...string) {
	t.Helper()
	gitArgs := append([]string{"-C", dir}, args...)
	cmd := exec.Command("git", gitArgs...)
	out, err := cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("git %v failed: %v\n%s", args, err, out)
	}
}

func initTestRepo(t *testing.T) string {
	t.Helper()
	dir := t.TempDir()
	runGitForTest(t, dir, "init")
	runGitForTest(t, dir, "-c", "user.email=test@example.com", "-c", "user.name=Test", "commit", "--allow-empty", "-m", "initial")
	return dir
}

func TestGitStatusToolShowsChangedFiles(t *testing.T) {
	requireGit(t)
	dir := initTestRepo(t)

	path := filepath.Join(dir, "tracked.txt")
	if err := os.WriteFile(path, []byte("hello"), 0o644); err != nil {
		t.Fatal(err)
	}
	runGitForTest(t, dir, "add", "tracked.txt")
	runGitForTest(t, dir, "-c", "user.email=test@example.com", "-c", "user.name=Test", "commit", "-m", "add tracked")

	if err := os.WriteFile(path, []byte("world"), 0o644); err != nil {
		t.Fatal(err)
	}

	tool := NewGitStatusTool(dir)
	out, err := tool.Execute(context.Background(), nil)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(out, "Changed files:") {
		t.Fatalf("output missing 'Changed files:': %q", out)
	}
	if !strings.Contains(out, "M tracked.txt") {
		t.Fatalf("output missing 'M tracked.txt': %q", out)
	}
}

func TestGitDiffToolShowsUnstagedDiff(t *testing.T) {
	requireGit(t)
	dir := initTestRepo(t)

	path := filepath.Join(dir, "tracked.txt")
	if err := os.WriteFile(path, []byte("hello"), 0o644); err != nil {
		t.Fatal(err)
	}
	runGitForTest(t, dir, "add", "tracked.txt")
	runGitForTest(t, dir, "-c", "user.email=test@example.com", "-c", "user.name=Test", "commit", "-m", "add tracked")

	if err := os.WriteFile(path, []byte("world"), 0o644); err != nil {
		t.Fatal(err)
	}

	tool := NewGitDiffTool(dir)
	out, err := tool.Execute(context.Background(), nil)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(out, "diff --git") {
		t.Fatalf("output missing 'diff --git': %q", out)
	}
}

func TestGitDiffToolShowsStat(t *testing.T) {
	requireGit(t)
	dir := initTestRepo(t)

	path := filepath.Join(dir, "tracked.txt")
	if err := os.WriteFile(path, []byte("hello"), 0o644); err != nil {
		t.Fatal(err)
	}
	runGitForTest(t, dir, "add", "tracked.txt")
	runGitForTest(t, dir, "-c", "user.email=test@example.com", "-c", "user.name=Test", "commit", "-m", "add tracked")

	if err := os.WriteFile(path, []byte("world"), 0o644); err != nil {
		t.Fatal(err)
	}

	tool := NewGitDiffTool(dir)
	out, err := tool.Execute(context.Background(), json.RawMessage(`{"stat":true}`))
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(out, "tracked.txt") {
		t.Fatalf("output missing 'tracked.txt': %q", out)
	}
}

func TestGitLogToolShowsCommits(t *testing.T) {
	requireGit(t)
	dir := initTestRepo(t)

	tool := NewGitLogTool(dir)
	out, err := tool.Execute(context.Background(), json.RawMessage(`{"max_count":1}`))
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(out, "initial") {
		t.Fatalf("output missing 'initial': %q", out)
	}
}

func TestGitToolsRejectEscapingPath(t *testing.T) {
	requireGit(t)
	dir := initTestRepo(t)

	tool := NewGitStatusTool(dir)
	_, err := tool.Execute(context.Background(), json.RawMessage(`{"path":"../outside"}`))
	if err == nil {
		t.Fatal("expected error for escaping path")
	}
	if !strings.Contains(err.Error(), "escapes") {
		t.Fatalf("error = %v", err)
	}
}