package session

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

func isolate(t *testing.T) {
	t.Helper()
	t.Setenv("XDG_CONFIG_HOME", t.TempDir())
}

func TestSaveThenLoad(t *testing.T) {
	isolate(t)
	if got := Load("https://terdut.example.com"); got != "" {
		t.Fatalf("expected no session yet, got %q", got)
	}
	if err := Save("https://terdut.example.com", "tok"); err != nil {
		t.Fatalf("save: %v", err)
	}
	if got := Load("https://terdut.example.com"); got != "tok" {
		t.Errorf("expected tok, got %q", got)
	}
	// A trailing slash is the same server.
	if got := Load("https://terdut.example.com/"); got != "tok" {
		t.Errorf("a trailing slash should not lose the session, got %q", got)
	}
}

// A token is only ever valid for the server that issued it; offering it to a
// different one would send a credential to somebody it was never meant for.
func TestLoadIgnoresAnotherServersSession(t *testing.T) {
	isolate(t)
	if err := Save("https://a.example.com", "tok"); err != nil {
		t.Fatal(err)
	}
	if got := Load("https://b.example.com"); got != "" {
		t.Errorf("a session for another server must not be reused, got %q", got)
	}
}

func TestSaveIsOwnerOnly(t *testing.T) {
	isolate(t)
	if err := Save("https://a.example.com", "tok"); err != nil {
		t.Fatal(err)
	}
	p, _ := path()
	info, err := os.Stat(p)
	if err != nil {
		t.Fatal(err)
	}
	if perm := info.Mode().Perm(); perm != 0o600 {
		t.Errorf("the session file holds a credential and must be 0600, got %o", perm)
	}
	entries, _ := os.ReadDir(filepath.Dir(p))
	for _, e := range entries {
		if e.Name() != "session.json" {
			t.Errorf("a temporary file was left behind: %s", e.Name())
		}
	}
}

func TestClear(t *testing.T) {
	isolate(t)
	if err := Clear(); err != nil {
		t.Errorf("clearing nothing is not an error, got %v", err)
	}
	if err := Save("https://a.example.com", "tok"); err != nil {
		t.Fatal(err)
	}
	if err := Clear(); err != nil {
		t.Fatalf("clear: %v", err)
	}
	if got := Load("https://a.example.com"); got != "" {
		t.Errorf("expected the session gone, got %q", got)
	}
}

func TestLoadToleratesGarbage(t *testing.T) {
	isolate(t)
	p, _ := path()
	if err := os.MkdirAll(filepath.Dir(p), 0o700); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(p, []byte("{not json"), 0o600); err != nil {
		t.Fatal(err)
	}
	if got := Load("https://a.example.com"); got != "" {
		t.Errorf("an unreadable file means no session, got %q", got)
	}
}