package builtin

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

	"nub/internal/tool"
)

func testEnv(t *testing.T) tool.Env {
	t.Helper()
	dir := t.TempDir()
	return tool.Env{Cwd: dir, RepoRoot: dir}
}

func writeFile(t *testing.T, env tool.Env, name, content string) string {
	t.Helper()
	path := filepath.Join(env.RepoRoot, name)
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
		t.Fatal(err)
	}
	return path
}

func TestEdit_AmbiguousMatchErrorsWithCount(t *testing.T) {
	env := testEnv(t)
	writeFile(t, env, "f.go", "foo\nfoo\nfoo\n")

	in, _ := json.Marshal(map[string]any{"path": "f.go", "old_string": "foo", "new_string": "bar"})
	res, err := EditTool{}.Run(context.Background(), in, env)
	if err != nil {
		t.Fatal(err)
	}
	if !res.IsError {
		t.Fatal("expected IsError for ambiguous match")
	}
	if !contains(res.ForModel, "3 matches") {
		t.Errorf("error message should mention match count, got: %q", res.ForModel)
	}
}

func TestEdit_ReplaceAllReplacesEveryMatch(t *testing.T) {
	env := testEnv(t)
	path := writeFile(t, env, "f.go", "foo\nfoo\nfoo\n")

	in, _ := json.Marshal(map[string]any{"path": "f.go", "old_string": "foo", "new_string": "bar", "replace_all": true})
	res, err := EditTool{}.Run(context.Background(), in, env)
	if err != nil {
		t.Fatal(err)
	}
	if res.IsError {
		t.Fatalf("unexpected error: %s", res.ForModel)
	}
	data, _ := os.ReadFile(path)
	if string(data) != "bar\nbar\nbar\n" {
		t.Errorf("content = %q", data)
	}
}

func TestEdit_UniqueMatchSucceeds(t *testing.T) {
	env := testEnv(t)
	writeFile(t, env, "f.go", "unique_marker\nother\n")

	in, _ := json.Marshal(map[string]any{"path": "f.go", "old_string": "unique_marker", "new_string": "replaced"})
	res, err := EditTool{}.Run(context.Background(), in, env)
	if err != nil {
		t.Fatal(err)
	}
	if res.IsError {
		t.Fatalf("unexpected error: %s", res.ForModel)
	}
}

func TestPath_EscapeViaDotDotIsRejected(t *testing.T) {
	env := testEnv(t)
	in, _ := json.Marshal(map[string]any{"path": "../outside.txt", "old_string": "a", "new_string": "b"})
	res, err := EditTool{}.Run(context.Background(), in, env)
	if err != nil {
		t.Fatal(err)
	}
	if !res.IsError {
		t.Fatal("expected path escape to be rejected")
	}
}

func TestPath_EscapeViaSymlinkIsRejected(t *testing.T) {
	env := testEnv(t)
	outsideDir := t.TempDir()
	if err := os.WriteFile(filepath.Join(outsideDir, "secret.txt"), []byte("secret"), 0o644); err != nil {
		t.Fatal(err)
	}
	link := filepath.Join(env.RepoRoot, "link")
	if err := os.Symlink(outsideDir, link); err != nil {
		t.Skipf("symlinks not supported: %v", err)
	}

	in, _ := json.Marshal(map[string]any{"path": "link/secret.txt"})
	res, err := ReadTool{}.Run(context.Background(), in, env)
	if err != nil {
		t.Fatal(err)
	}
	if !res.IsError {
		t.Fatal("expected symlink escape to be rejected")
	}
}

func TestBash_TimeoutKillsProcessGroup(t *testing.T) {
	env := testEnv(t)
	in, _ := json.Marshal(map[string]any{"command": "sleep 30", "timeout_seconds": 1})

	start := time.Now()
	res, err := BashTool{}.Run(context.Background(), in, env)
	elapsed := time.Since(start)

	if err != nil {
		t.Fatal(err)
	}
	if !res.IsError {
		t.Fatal("expected timeout to be reported as error")
	}
	if elapsed > 5*time.Second {
		t.Errorf("timeout took too long: %s", elapsed)
	}
}

func TestBash_CapturesStdoutAndExitCode(t *testing.T) {
	env := testEnv(t)
	in, _ := json.Marshal(map[string]any{"command": "echo hi && exit 3"})

	res, err := BashTool{}.Run(context.Background(), in, env)
	if err != nil {
		t.Fatal(err)
	}
	if !res.IsError {
		t.Fatal("expected non-zero exit to be reported as error")
	}
	if !contains(res.ForModel, "hi") {
		t.Errorf("expected stdout captured, got: %q", res.ForModel)
	}
}

func TestGlob_RespectsGitignore(t *testing.T) {
	env := testEnv(t)
	writeFile(t, env, ".gitignore", "*.log\n")
	writeFile(t, env, "keep.txt", "x")
	writeFile(t, env, "skip.log", "x")

	in, _ := json.Marshal(map[string]any{"pattern": "**/*"})
	res, err := GlobTool{}.Run(context.Background(), in, env)
	if err != nil {
		t.Fatal(err)
	}
	if contains(res.ForModel, "skip.log") {
		t.Errorf("gitignored file leaked into glob result: %q", res.ForModel)
	}
	if !contains(res.ForModel, "keep.txt") {
		t.Errorf("expected keep.txt in result: %q", res.ForModel)
	}
}

func contains(s, sub string) bool {
	return len(s) >= len(sub) && (func() bool {
		for i := 0; i+len(sub) <= len(s); i++ {
			if s[i:i+len(sub)] == sub {
				return true
			}
		}
		return false
	})()
}