// Copyright (C) 2026 Dcntrlized
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package owner

import (
	"context"
	"errors"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"testing"
)

func newTestStore(t *testing.T) *FileOwnerStore {
	t.Helper()
	s, err := NewFileOwnerStore(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	return s
}

func TestHashAndVerifyPassword(t *testing.T) {
	hash, err := HashPassword("correct horse battery")
	if err != nil {
		t.Fatal(err)
	}
	if !strings.HasPrefix(hash, "$argon2id$v=19$m=65536,t=3,p=2$") {
		t.Fatalf("hash missing argon2id PHC prefix: %s", hash)
	}
	if !VerifyPassword(hash, "correct horse battery") {
		t.Fatal("correct password rejected")
	}
	if VerifyPassword(hash, "wrong password!") {
		t.Fatal("wrong password accepted")
	}
	if VerifyPassword("garbage", "x") {
		t.Fatal("garbage hash accepted")
	}
}

func TestValidateCredentials(t *testing.T) {
	good := [][2]string{{"admin", "longenough123"}, {"a.b-c_d1", "0123456789"}}
	for _, c := range good {
		if err := ValidateCredentials(c[0], c[1]); err != nil {
			t.Errorf("%q/%q rejected: %v", c[0], c[1], err)
		}
	}
	bad := [][2]string{
		{"Admin", "0123456789"}, // uppercase
		{"-lead", "0123456789"}, // bad first char
		{"ab", "0123456789"},    // too short
		{"okname", "short"},     // weak password
	}
	for _, c := range bad {
		if err := ValidateCredentials(c[0], c[1]); err == nil {
			t.Errorf("%q/%q accepted", c[0], c[1])
		}
	}
}

func TestStoreRoundtripAndMultiUser(t *testing.T) {
	ctx := context.Background()
	s := newTestStore(t)

	if n, _ := s.Count(ctx); n != 0 {
		t.Fatalf("fresh store Count = %d", n)
	}
	first, err := s.Create(ctx, "admin", "first-owner-pass", true)
	if err != nil {
		t.Fatal(err)
	}
	if !first.IsAdmin || first.Role() != "admin" {
		t.Fatalf("first owner should be admin, got %+v", first)
	}
	second, err := s.Create(ctx, "member", "second-owner-pass", false)
	if err != nil {
		t.Fatal(err)
	}
	if second.Role() != "member" {
		t.Fatalf("second owner role = %q", second.Role())
	}
	if n, _ := s.Count(ctx); n != 2 {
		t.Fatalf("Count = %d, want 2", n)
	}

	if got, err := s.Verify(ctx, "admin", "first-owner-pass"); err != nil || got.Username != "admin" {
		t.Fatalf("Verify admin: %v %+v", err, got)
	}
	if _, err := s.Verify(ctx, "admin", "wrong"); !errors.Is(err, os.ErrNotExist) {
		t.Fatalf("wrong password: %v", err)
	}
	if _, err := s.Create(ctx, "admin", "whatever-123", false); !errors.Is(err, os.ErrExist) {
		t.Fatalf("duplicate create: %v", err)
	}

	changed, err := s.ChangePassword(ctx, "admin", "first-owner-pass", "rotated-password")
	if err != nil {
		t.Fatal(err)
	}
	if changed.UpdatedAt.Equal(changed.CreatedAt) {
		t.Fatal("updated_at not bumped")
	}
	if _, err := s.Verify(ctx, "admin", "first-owner-pass"); err == nil {
		t.Fatal("old password still valid")
	}
	if _, err := s.Verify(ctx, "admin", "rotated-password"); err != nil {
		t.Fatalf("new password rejected: %v", err)
	}
}

func TestConcurrentCreateIsIdempotent(t *testing.T) {
	ctx := context.Background()
	s := newTestStore(t)

	var wg sync.WaitGroup
	errs := make(chan error, 16)
	for i := 0; i < 16; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			if _, err := s.Create(ctx, "wizard", "setup-password", true); err != nil && !errors.Is(err, os.ErrExist) {
				errs <- err
			}
		}()
	}
	wg.Wait()
	close(errs)
	for err := range errs {
		t.Fatalf("unexpected error: %v", err)
	}
	if n, _ := s.Count(ctx); n != 1 {
		t.Fatalf("Count after concurrent setup = %d, want 1", n)
	}
}

func TestOwnerFilePermissions(t *testing.T) {
	ctx := context.Background()
	dir := t.TempDir()
	s, err := NewFileOwnerStore(dir)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := s.Create(ctx, "admin", "perm-check-pass", true); err != nil {
		t.Fatal(err)
	}
	info, err := os.Stat(filepath.Join(dir, "owners.json"))
	if err != nil {
		t.Fatal(err)
	}
	if perm := info.Mode().Perm(); perm != 0o600 {
		t.Fatalf("owners.json mode = %o, want 600", perm)
	}
}