package builtin

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

func TestGitignoreTool_Add_NewFile(t *testing.T) {
	dir := t.TempDir()
	tool := NewGitignoreTool(dir)

	input, _ := json.Marshal(map[string]any{
		"action":   "add",
		"patterns": []string{"*.log", "dist/"},
	})
	res, err := tool.Execute(context.Background(), input, nil)
	if err != nil {
		t.Fatal(err)
	}
	if res.IsError {
		t.Fatalf("unexpected error: %s", res.Output)
	}

	content, _ := os.ReadFile(filepath.Join(dir, ".gitignore"))
	if !containsLine(string(content), "*.log") || !containsLine(string(content), "dist/") {
		t.Errorf("expected patterns in .gitignore, got: %s", content)
	}
}

func TestGitignoreTool_Add_Idempotent(t *testing.T) {
	dir := t.TempDir()
	tool := NewGitignoreTool(dir)

	input, _ := json.Marshal(map[string]any{
		"action":   "add",
		"patterns": []string{"*.log"},
	})
	// 添加两次
	tool.Execute(context.Background(), input, nil)
	tool.Execute(context.Background(), input, nil)

	content, _ := os.ReadFile(filepath.Join(dir, ".gitignore"))
	count := countLines(string(content), "*.log")
	if count != 1 {
		t.Errorf("expected 1 occurrence of *.log, got %d", count)
	}
}

func TestGitignoreTool_Add_Append(t *testing.T) {
	dir := t.TempDir()
	os.WriteFile(filepath.Join(dir, ".gitignore"), []byte("node_modules/\n"), 0644)

	tool := NewGitignoreTool(dir)
	input, _ := json.Marshal(map[string]any{
		"action":   "add",
		"patterns": []string{"*.tmp"},
	})
	tool.Execute(context.Background(), input, nil)

	content, _ := os.ReadFile(filepath.Join(dir, ".gitignore"))
	if !containsLine(string(content), "node_modules/") || !containsLine(string(content), "*.tmp") {
		t.Errorf("expected both patterns, got: %s", content)
	}
}

func TestGitignoreTool_Check_Ignored(t *testing.T) {
	dir := t.TempDir()
	os.WriteFile(filepath.Join(dir, ".gitignore"), []byte("*.log\n"), 0644)

	tool := NewGitignoreTool(dir)
	input, _ := json.Marshal(map[string]any{
		"action": "check",
		"path":   "app.log",
	})
	res, err := tool.Execute(context.Background(), input, nil)
	if err != nil || res.IsError {
		t.Fatalf("unexpected error: %v %s", err, res.Output)
	}
	dataMap, ok := res.Data.(map[string]any)
	if !ok {
		t.Fatalf("expected Data to be map, got %T", res.Data)
	}
	if ignored, _ := dataMap["ignored"].(bool); !ignored {
		t.Errorf("expected ignored=true, got output: %s", res.Output)
	}
}

func TestGitignoreTool_Check_NotIgnored(t *testing.T) {
	dir := t.TempDir()
	os.WriteFile(filepath.Join(dir, ".gitignore"), []byte("*.log\n"), 0644)

	tool := NewGitignoreTool(dir)
	input, _ := json.Marshal(map[string]any{
		"action": "check",
		"path":   "main.go",
	})
	res, _ := tool.Execute(context.Background(), input, nil)
	dataMap, ok := res.Data.(map[string]any)
	if !ok {
		t.Fatalf("expected Data to be map, got %T", res.Data)
	}
	if ignored, _ := dataMap["ignored"].(bool); ignored {
		t.Errorf("expected ignored=false, got output: %s", res.Output)
	}
}

func TestGitignoreTool_InvalidAction(t *testing.T) {
	tool := NewGitignoreTool(t.TempDir())
	input, _ := json.Marshal(map[string]any{"action": "delete"})
	res, _ := tool.Execute(context.Background(), input, nil)
	if !res.IsError {
		t.Error("expected error for unknown action")
	}
}

// containsLine checks if s contains line as a complete line.
func containsLine(s, line string) bool {
	for _, l := range splitLines(s) {
		if l == line {
			return true
		}
	}
	return false
}

func countLines(s, line string) int {
	n := 0
	for _, l := range splitLines(s) {
		if l == line {
			n++
		}
	}
	return n
}

func splitLines(s string) []string {
	var lines []string
	for _, l := range filepath.SplitList(s) {
		_ = l
	}
	// 用 strings.Split 实现
	cur := ""
	for _, ch := range s {
		if ch == '\n' {
			lines = append(lines, cur)
			cur = ""
		} else {
			cur += string(ch)
		}
	}
	if cur != "" {
		lines = append(lines, cur)
	}
	return lines
}