package safety

import (
	"os"
	"path/filepath"
	"sort"
	"testing"
)

func TestScanCWDForSensitive_Matches(t *testing.T) {
	dir := t.TempDir()
	// Sensitive files we expect to flag.
	sensitive := []string{
		".env",
		".env.local",
		"id_rsa",
		"private.pem",
		"aws_credentials",
		".netrc",
		"vault.kdbx",
	}
	// Non-sensitive control files.
	control := []string{
		".envrc", // direnv config, not a credential
		"main.go",
		"README.md",
		"secret_handler.go", // source code, not data
	}
	for _, f := range sensitive {
		if err := os.WriteFile(filepath.Join(dir, f), []byte("x"), 0o600); err != nil {
			t.Fatal(err)
		}
	}
	for _, f := range control {
		if err := os.WriteFile(filepath.Join(dir, f), []byte("x"), 0o600); err != nil {
			t.Fatal(err)
		}
	}
	// Sensitive directory.
	if err := os.MkdirAll(filepath.Join(dir, ".ssh"), 0o700); err != nil {
		t.Fatal(err)
	}

	matches := ScanCWDForSensitive(dir)

	wantNames := append([]string{}, sensitive...)
	wantNames = append(wantNames, ".ssh")
	sort.Strings(wantNames)

	gotNames := make([]string, 0, len(matches))
	for _, m := range matches {
		gotNames = append(gotNames, filepath.Base(m.Path))
	}
	sort.Strings(gotNames)

	if len(gotNames) != len(wantNames) {
		t.Errorf("matched %d files (%v), want %d (%v)", len(gotNames), gotNames, len(wantNames), wantNames)
	}
	for i, n := range wantNames {
		if i >= len(gotNames) || gotNames[i] != n {
			t.Errorf("match[%d] = %q, want %q (got=%v want=%v)", i, gotNames[i], n, gotNames, wantNames)
		}
	}
}

func TestScanCWDForSensitive_EmptyDir(t *testing.T) {
	dir := t.TempDir()
	matches := ScanCWDForSensitive(dir)
	if len(matches) != 0 {
		t.Errorf("empty dir matched %v, want none", matches)
	}
}

func TestScanCWDForSensitive_PrecisionNoFalsePositives(t *testing.T) {
	dir := t.TempDir()
	// Files that look credential-y but conventionally hold no
	// secrets — must NOT be flagged.
	control := []string{
		".envrc",            // direnv config
		"secret_handler.go", // source code
		".env.example",      // template
		".env.sample",       // template
		".env.template",     // template
		".env.dist",         // template
		".env.default",      // template
		"env.local.example", // template
	}
	for _, name := range control {
		if err := os.WriteFile(filepath.Join(dir, name), []byte("x"), 0o600); err != nil {
			t.Fatal(err)
		}
	}

	matches := ScanCWDForSensitive(dir)
	if len(matches) != 0 {
		names := make([]string, 0, len(matches))
		for _, m := range matches {
			names = append(names, filepath.Base(m.Path))
		}
		t.Errorf("precision regression: none of %v should flag, got %v", control, names)
	}
}

func TestScanCWDForSensitive_RealEnvFilesStillMatch(t *testing.T) {
	dir := t.TempDir()
	// Real env files (non-template) must still be flagged.
	real := []string{
		".env",
		".env.local",
		".env.production",
		".env.staging",
		"env.local",
		"env.local.production",
	}
	for _, name := range real {
		if err := os.WriteFile(filepath.Join(dir, name), []byte("API_KEY=secret"), 0o600); err != nil {
			t.Fatal(err)
		}
	}
	matches := ScanCWDForSensitive(dir)
	if len(matches) != len(real) {
		got := make([]string, 0, len(matches))
		for _, m := range matches {
			got = append(got, filepath.Base(m.Path))
		}
		t.Errorf("expected %d real env files flagged, got %d (%v)", len(real), len(matches), got)
	}
}

func TestScanCWDForSensitive_BoundedScan(t *testing.T) {
	dir := t.TempDir()
	// Populate just over the scan limit. The function should not panic
	// or hang. Result count is at most scanLimit (matches may be 0 if
	// the entries beyond the cap happen to be sensitive — that's OK,
	// the bound is a safety knob, not a correctness one).
	for i := 0; i < scanLimit+10; i++ {
		if err := os.WriteFile(filepath.Join(dir, "file"+itoa(i)), []byte("x"), 0o600); err != nil {
			t.Fatal(err)
		}
	}
	_ = ScanCWDForSensitive(dir) // mustn't panic
}

// itoa avoids importing strconv just for one use.
func itoa(n int) string {
	if n == 0 {
		return "0"
	}
	var buf [20]byte
	i := len(buf)
	for n > 0 {
		i--
		buf[i] = byte('0' + n%10)
		n /= 10
	}
	return string(buf[i:])
}