package tools

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

func TestFileEditReplacesLineRange(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "notes.txt")
	if err := os.WriteFile(path, []byte("one\ntwo\nthree\n"), 0o644); err != nil {
		t.Fatal(err)
	}

	edit := NewFileEditTool(dir)
	out, err := edit.Execute(context.Background(), json.RawMessage(`{"path":"notes.txt","start_line":2,"end_line":2,"new":"TWO\n"}`))
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(out, "replaced lines 2-2") {
		t.Fatalf("output = %q", out)
	}
	got, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	if string(got) != "one\nTWO\nthree\n" {
		t.Fatalf("file content = %q", string(got))
	}
}

func TestFileEditReplacesExactPattern(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "notes.txt")
	if err := os.WriteFile(path, []byte("alpha beta alpha"), 0o644); err != nil {
		t.Fatal(err)
	}

	edit := NewFileEditTool(dir)
	out, err := edit.Execute(context.Background(), json.RawMessage(`{"path":"notes.txt","old":"beta","new":"BETA"}`))
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(out, "replaced 1 occurrence") {
		t.Fatalf("output = %q", out)
	}
	got, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	if string(got) != "alpha BETA alpha" {
		t.Fatalf("file content = %q", string(got))
	}
}

func TestFileEditRejectsAmbiguousPattern(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "notes.txt")
	if err := os.WriteFile(path, []byte("x x"), 0o644); err != nil {
		t.Fatal(err)
	}

	edit := NewFileEditTool(dir)
	_, err := edit.Execute(context.Background(), json.RawMessage(`{"path":"notes.txt","old":"x","new":"y"}`))
	if err == nil {
		t.Fatal("expected error for ambiguous pattern")
	}
	if !strings.Contains(err.Error(), "matched 2 occurrences") {
		t.Fatalf("error = %v", err)
	}
}

func TestFileEditReplaceAll(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "notes.txt")
	if err := os.WriteFile(path, []byte("x x"), 0o644); err != nil {
		t.Fatal(err)
	}

	edit := NewFileEditTool(dir)
	out, err := edit.Execute(context.Background(), json.RawMessage(`{"path":"notes.txt","old":"x","new":"y","replace_all":true}`))
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(out, "replaced 2 occurrences") {
		t.Fatalf("output = %q", out)
	}
	got, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	if string(got) != "y y" {
		t.Fatalf("file content = %q", string(got))
	}
}

func TestFileEditRejectsEscapingPath(t *testing.T) {
	dir := t.TempDir()
	edit := NewFileEditTool(dir)
	_, err := edit.Execute(context.Background(), json.RawMessage(`{"path":"../outside.txt","old":"x","new":"y"}`))
	if err == nil {
		t.Fatal("expected error for escaping path")
	}
	if !strings.Contains(err.Error(), "escapes") {
		t.Fatalf("error = %v", err)
	}
}

func TestFileEditRejectsMissingNew(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "notes.txt")
	if err := os.WriteFile(path, []byte("hello"), 0o644); err != nil {
		t.Fatal(err)
	}
	edit := NewFileEditTool(dir)
	_, err := edit.Execute(context.Background(), json.RawMessage(`{"path":"notes.txt","old":"hello"}`))
	if err == nil {
		t.Fatal("expected error for missing new")
	}
	if !strings.Contains(err.Error(), "new is required") {
		t.Fatalf("error = %v", err)
	}
}

func TestFileEditRejectsNonExistentFile(t *testing.T) {
	dir := t.TempDir()
	edit := NewFileEditTool(dir)
	_, err := edit.Execute(context.Background(), json.RawMessage(`{"path":"missing.txt","old":"x","new":"y"}`))
	if err == nil {
		t.Fatal("expected error for non-existent file")
	}
}