package postgres

import (
	"context"
	"database/sql"
	"errors"
	"reflect"
	"testing"

	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/identity"
)

func TestFindAuthorizationSnapshotLoadsAccountAndOrganizationInOneQuery(t *testing.T) {
	const wantSQL = `SELECT
  u.id,
  u.phone,
  u.display_name,
  u.role,
  u.organization_id,
  u.status,
  u.session_version,
  o.id,
  o.name,
  o.status
FROM public.platform_users AS u
LEFT JOIN public.platform_organizations AS o ON o.id = u.organization_id
WHERE u.id = $1::text`
	rows := &identityRows{rows: [][]any{{
		"account-1", "13800138000", "Zhang San", "organization_admin", "organization-1", "active", 7,
		"organization-1", "Acme", "active",
	}}}
	querier := &identityQuerier{rows: rows}
	db := NewDatabase(Config{Backend: BackendPostgres}, querier)

	got, found, err := db.FindAuthorizationSnapshot(context.Background(), "account-1")
	if err != nil {
		t.Fatalf("FindAuthorizationSnapshot() error = %v", err)
	}
	if !found {
		t.Fatal("FindAuthorizationSnapshot() found = false, want true")
	}
	if querier.sql != wantSQL || !reflect.DeepEqual(querier.args, []any{"account-1"}) {
		t.Fatalf("query = %q args = %#v, want exact SQL and identity argument", querier.sql, querier.args)
	}
	want := identity.AuthorizationSnapshot{
		Account: identity.AccountSnapshot{
			ID: "account-1", Phone: "13800138000", DisplayName: "Zhang San", Role: "organization_admin",
			OrganizationID: "organization-1", Status: "active", SessionVersion: 7,
		},
		Organization: &identity.OrganizationSnapshot{ID: "organization-1", Name: "Acme", Status: "active"},
	}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("FindAuthorizationSnapshot() = %#v, want %#v", got, want)
	}
}

func TestFindAuthorizationSnapshotLoadsUnboundSuperAdminWithNoOrganization(t *testing.T) {
	querier := &identityQuerier{rows: &identityRows{rows: [][]any{{
		"super-1", "13900139000", "Root", "super_admin", nil, "active", 4,
		nil, nil, nil,
	}}}}
	db := NewDatabase(Config{Backend: BackendPostgres}, querier)

	got, found, err := db.FindAuthorizationSnapshot(context.Background(), "super-1")
	if err != nil {
		t.Fatalf("FindAuthorizationSnapshot() error = %v", err)
	}
	if !found || got.Account.OrganizationID != "" || got.Organization != nil {
		t.Fatalf("FindAuthorizationSnapshot() = (%#v, %v), want unbound account and nil organization", got, found)
	}
}

func TestFindAuthorizationSnapshotReturnsNotFoundForNoAccount(t *testing.T) {
	db := NewDatabase(Config{Backend: BackendPostgres}, &identityQuerier{rows: &identityRows{}})

	got, found, err := db.FindAuthorizationSnapshot(context.Background(), "missing")
	if err != nil || found || !reflect.DeepEqual(got, identity.AuthorizationSnapshot{}) {
		t.Fatalf("FindAuthorizationSnapshot() = (%#v, %v, %v), want zero, false, nil", got, found, err)
	}
}

func TestFindAuthorizationSnapshotPropagatesDatabaseFailures(t *testing.T) {
	queryErr := errors.New("query failed")
	scanErr := errors.New("scan failed")
	rowsErr := errors.New("rows failed")
	tests := []struct {
		name    string
		querier *identityQuerier
		wantErr error
	}{
		{name: "query", querier: &identityQuerier{err: queryErr}, wantErr: queryErr},
		{name: "scan", querier: &identityQuerier{rows: &identityRows{rows: [][]any{{nil}}, scanErr: scanErr}}, wantErr: scanErr},
		{name: "rows before first row", querier: &identityQuerier{rows: &identityRows{err: rowsErr}}, wantErr: rowsErr},
		{name: "rows after scan", querier: &identityQuerier{rows: &identityRows{
			rows: [][]any{{"account-1", "13800138000", "Name", "user", "org-1", "active", 1, "org-1", "Org", "active"}},
			err:  rowsErr,
		}}, wantErr: rowsErr},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			db := NewDatabase(Config{Backend: BackendPostgres}, test.querier)
			got, found, err := db.FindAuthorizationSnapshot(context.Background(), "account-1")
			if !errors.Is(err, test.wantErr) {
				t.Fatalf("FindAuthorizationSnapshot() error = %v, want wrapping %v", err, test.wantErr)
			}
			if found || !reflect.DeepEqual(got, identity.AuthorizationSnapshot{}) {
				t.Fatalf("FindAuthorizationSnapshot() = (%#v, %v), want fail-closed zero result", got, found)
			}
		})
	}
}

func TestFindAuthorizationSnapshotFailsClosedWithoutPostgres(t *testing.T) {
	tests := []struct {
		name    string
		config  Config
		querier Querier
	}{
		{name: "local backend", config: Config{Backend: BackendLocal}, querier: &identityQuerier{err: errors.New("must not query")}},
		{name: "unavailable pool", config: Config{Backend: BackendPostgres}},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			db := NewDatabase(test.config, test.querier)
			got, found, err := db.FindAuthorizationSnapshot(context.Background(), "account-1")
			if err == nil || found || !reflect.DeepEqual(got, identity.AuthorizationSnapshot{}) {
				t.Fatalf("FindAuthorizationSnapshot() = (%#v, %v, %v), want fail-closed error", got, found, err)
			}
			if querier, ok := test.querier.(*identityQuerier); ok && querier.called {
				t.Fatal("FindAuthorizationSnapshot() queried while PostgreSQL was unavailable")
			}
		})
	}
}

var _ identity.AuthorizationSnapshotLoader = (*Database)(nil)

type identityQuerier struct {
	rows   *identityRows
	err    error
	sql    string
	args   []any
	called bool
}

func (q *identityQuerier) Query(_ context.Context, query string, args ...any) (Rows, error) {
	q.called = true
	q.sql = query
	q.args = args
	return q.rows, q.err
}

type identityRows struct {
	rows    [][]any
	idx     int
	err     error
	scanErr error
}

func (r *identityRows) Close()     {}
func (r *identityRows) Err() error { return r.err }
func (r *identityRows) Next() bool { return r.idx < len(r.rows) }

func (r *identityRows) Scan(dest ...any) error {
	if r.scanErr != nil {
		return r.scanErr
	}
	if r.idx >= len(r.rows) {
		return errors.New("scan past end")
	}
	row := r.rows[r.idx]
	r.idx++
	if len(dest) != len(row) {
		return errors.New("scan arity mismatch")
	}
	for index, target := range dest {
		value := row[index]
		switch target := target.(type) {
		case *string:
			text, ok := value.(string)
			if !ok {
				return errors.New("scan string type mismatch")
			}
			*target = text
		case *int:
			number, ok := value.(int)
			if !ok {
				return errors.New("scan int type mismatch")
			}
			*target = number
		case *sql.NullString:
			if value == nil {
				*target = sql.NullString{}
				continue
			}
			text, ok := value.(string)
			if !ok {
				return errors.New("scan nullable string type mismatch")
			}
			*target = sql.NullString{String: text, Valid: true}
		default:
			return errors.New("unsupported scan target")
		}
	}
	return nil
}