package store

import (
	"errors"
	"sort"
)

// SetAccountEnabled changes only the effective account state. The actor and
// target are rechecked inside one transaction; disabling also consumes every
// existing credential handle. A global manager lock serializes the last-admin
// decision across PostgreSQL connections.
func (s *Store) SetAccountEnabled(actorOwner, userID string, expectedStateVersion int64, enabled bool) (Account, error) {
	if expectedStateVersion < 1 {
		return Account{}, ErrConflict
	}
	pre, err := s.GetAccount(userID)
	if err != nil {
		return Account{}, err
	}
	tx, err := s.db.Begin()
	if err != nil {
		return Account{}, err
	}
	defer tx.Rollback()
	owners := []string{actorOwner, pre.Owner}
	sort.Strings(owners)
	for i, owner := range owners {
		if i > 0 && owner == owners[i-1] {
			continue
		}
		if err := s.dialect.lockAccount(tx, owner); err != nil {
			return Account{}, err
		}
	}
	if err := s.dialect.lockBootstrap(tx); err != nil {
		return Account{}, err
	}
	target, err := scanAccount(tx.QueryRow(s.q(`SELECT `+accountColumns+` FROM users WHERE id=?`), userID))
	if err != nil {
		return Account{}, err
	}
	locked, err := s.lockAccountUsers(tx, actorOwner, target.Owner)
	if errors.Is(err, ErrNotFound) {
		return Account{}, ErrAccountForbidden
	}
	if err != nil {
		return Account{}, err
	}
	actor, target := locked[actorOwner], locked[target.Owner]
	if !actor.Enabled || !actor.IsAdmin {
		return Account{}, ErrAccountForbidden
	}
	if target.ID != userID || target.StateVersion != expectedStateVersion || target.Enabled == enabled {
		return Account{}, ErrConflict
	}
	if !enabled && target.IsAdmin && target.HasPassword && !target.MustChangePassword {
		var managers int
		if err := tx.QueryRow(s.q(`SELECT COUNT(1) FROM users WHERE enabled=? AND is_admin=? AND password_hash<>'' AND must_change_password=?`), true, true, false).Scan(&managers); err != nil {
			return Account{}, err
		}
		if managers <= 1 {
			return Account{}, ErrConflict
		}
	}
	result, err := tx.Exec(s.q(`UPDATE users SET enabled=?,state_version=state_version+1,auth_version=auth_version+1 WHERE id=? AND state_version=?`), enabled, userID, expectedStateVersion)
	if err != nil {
		return Account{}, err
	}
	if n, err := result.RowsAffected(); err != nil {
		return Account{}, err
	} else if n != 1 {
		return Account{}, ErrConflict
	}
	if !enabled {
		if _, err := tx.Exec(s.q(`UPDATE api_keys SET revoked=? WHERE owner=? AND revoked=?`), 1, target.Owner, 0); err != nil {
			return Account{}, err
		}
		if _, err := tx.Exec(s.q(`DELETE FROM sessions WHERE owner=?`), target.Owner); err != nil {
			return Account{}, err
		}
		if _, err := tx.Exec(s.q(`UPDATE login_keys SET status=? WHERE owner=? AND status=?`), LoginKeyStatusRevoked, target.Owner, LoginKeyStatusUnused); err != nil {
			return Account{}, err
		}
		if _, err := tx.Exec(s.q(`UPDATE recovery_proposals SET status='revoked',version=version+1 WHERE owner=? AND status IN ('pending','confirmed')`), target.Owner); err != nil {
			return Account{}, err
		}
	}
	if err := s.bumpAccountDirectoryRevision(tx, true, false); err != nil {
		return Account{}, err
	}
	action := "account_enabled"
	if !enabled {
		action = "account_disabled"
	}
	if err := s.insertAccountEvent(tx, actorOwner, "account-state", target.Owner, action, ""); err != nil {
		return Account{}, err
	}
	if err := s.auditAccountMutation(tx, target.Owner, actorOwner, "account.state"); err != nil {
		return Account{}, err
	}
	if err := tx.Commit(); err != nil {
		return Account{}, err
	}
	target.Enabled, target.StateVersion, target.AuthVersion = enabled, expectedStateVersion+1, target.AuthVersion+1
	return target, nil
}