<?php

namespace SilverStripe\Security;

use SilverStripe\Core\Config\Config;
use SilverStripe\Forms\FormField;
use SilverStripe\ORM\DataObject;
use SilverStripe\ORM\SS_List;
use SilverStripe\ORM\ArrayList;
use SilverStripe\ORM\DataObjectInterface;
use SilverStripe\View\Requirements;
use InvalidArgumentException;

/**
 * Shows a categorized list of available permissions (through {@link Permission::get_codes()}).
 * Permissions which are assigned to a given {@link Group} record
 * (either directly, inherited from parent groups, or through a {@link PermissionRole})
 * will be checked automatically. All checkboxes for "inherited" permissions will be readonly.
 *
 * The field can gets its assignment data either from {@link Group} or {@link PermissionRole} records.
 */
class PermissionCheckboxSetField extends FormField {

	/**
	 * @var array Filter certain permission codes from the output.
	 * Useful to simplify the interface
	 */
	protected $hiddenPermissions = array();

	/**
	 * @var SS_List
	 */
	protected $records = null;

	/**
	 * @var array Array Nested array in same notation as {@link CheckboxSetField}.
	 */
	protected $source = null;

	/**
	 * @param String $name
	 * @param String $title
	 * @param String $managedClass
	 * @param String $filterField
	 * @param Group|SS_List $records One or more {@link Group} or {@link PermissionRole} records
	 *  used to determine permission checkboxes.
	 *  Caution: saveInto() can only be used with a single record, all inherited permissions will be marked readonly.
	 *  Setting multiple groups only makes sense in a readonly context. (Optional)
	 */
	public function __construct($name, $title, $managedClass, $filterField, $records = null) {
		$this->filterField = $filterField;
		$this->managedClass = $managedClass;

		if($records instanceof SS_List) {
			$this->records = $records;
		} elseif($records instanceof Group) {
			$this->records = new ArrayList(array($records));
		} elseif($records) {
			throw new InvalidArgumentException(
				'$record should be either a Group record, or a SS_List of Group records');
		}

		// Get all available codes in the system as a categorized nested array
		$this->source = Permission::get_codes(true);

		parent::__construct($name, $title);
	}

	/**
	 * @param array $codes
	 */
	public function setHiddenPermissions($codes) {
		$this->hiddenPermissions = $codes;
	}

	/**
	 * @return array
	 */
	public function getHiddenPermissions() {
		return $this->hiddenPermissions;
	}

	/**
	 * @param array $properties
	 * @return string
	 */
	public function Field($properties = array()) {
		$uninheritedCodes = array();
		$inheritedCodes = array();
		$records = ($this->records) ? $this->records : new ArrayList();

		// Get existing values from the form record (assuming the formfield name is a join field on the record)
		if(is_object($this->form)) {
			$record = $this->form->getRecord();
			if(
				$record
				&& ($record instanceof Group || $record instanceof PermissionRole)
				&& !$records->find('ID', $record->ID)
			) {
				$records->push($record);
			}
		}

		// Get all 'inherited' codes not directly assigned to the group (which is stored in $values)
		foreach($records as $record) {
			// Get all uninherited permissions
			$relationMethod = $this->name;
			foreach($record->$relationMethod() as $permission) {
				if(!isset($uninheritedCodes[$permission->Code])) $uninheritedCodes[$permission->Code] = array();
				$uninheritedCodes[$permission->Code][] = _t(
					'PermissionCheckboxSetField.AssignedTo', 'assigned to "{title}"',
					array('title' => $record->dbObject('Title')->forTemplate())
				);
			}

			// Special case for Group records (not PermissionRole):
			// Determine inherited assignments
			if ($record instanceof Group) {
				// Get all permissions from roles
				if ($record->Roles()->count()) {
					foreach($record->Roles() as $role) {
						/** @var PermissionRole $role */
						foreach($role->Codes() as $code) {
							if (!isset($inheritedCodes[$code->Code])) $inheritedCodes[$code->Code] = array();
							$inheritedCodes[$code->Code][] = _t(
								'PermissionCheckboxSetField.FromRole',
								'inherited from role "{title}"',
								'A permission inherited from a certain permission role',
								array('title' => $role->dbObject('Title')->forTemplate())
							);
						}
					}
				}

				// Get from parent groups
				$parentGroups = $record->getAncestors();
				if ($parentGroups) {
					foreach ($parentGroups as $parent) {
						if (!$parent->Roles()->Count()) continue;
						foreach($parent->Roles() as $role) {
							if ($role->Codes()) {
								foreach($role->Codes() as $code) {
									if (!isset($inheritedCodes[$code->Code])) $inheritedCodes[$code->Code] = array();
									$inheritedCodes[$code->Code][] = _t(
										'PermissionCheckboxSetField.FromRoleOnGroup',
										'inherited from role "%s" on group "%s"',
										'A permission inherited from a role on a certain group',
										array('roletitle' => $role->dbObject('Title')->forTemplate(), 'grouptitle' => $parent->dbObject('Title')->forTemplate())
									);
								}
							}
						}
						if ($parent->Permissions()->Count()) {
							foreach($parent->Permissions() as $permission) {
								if (!isset($inheritedCodes[$permission->Code])) {
									$inheritedCodes[$permission->Code] = array();
								}
								$inheritedCodes[$permission->Code][] =
								_t(
									'PermissionCheckboxSetField.FromGroup',
									'inherited from group "{title}"',
									'A permission inherited from a certain group',
									array('title' => $parent->dbObject('Title')->forTemplate())
								);
							}
						}
					}
				}
			}
		}

		$odd = 0;
		$options = '';
		$globalHidden = (array)Config::inst()->get('SilverStripe\\Security\\Permission', 'hidden_permissions');
		if($this->source) {
			$privilegedPermissions = Permission::config()->privileged_permissions;

			// loop through all available categorized permissions and see if they're assigned for the given groups
			foreach($this->source as $categoryName => $permissions) {
				$options .= "<li><h5>$categoryName</h5></li>";
				foreach($permissions as $code => $permission) {
					if(in_array($code, $this->hiddenPermissions)) continue;
					if(in_array($code, $globalHidden)) continue;

					$value = $permission['name'];

					$odd = ($odd + 1) % 2;
					$extraClass = $odd ? 'odd' : 'even';
					$extraClass .= ' val' . str_replace(' ', '', $code);
					$itemID = $this->ID() . '_' . preg_replace('/[^a-zA-Z0-9]+/', '', $code);
					$disabled = $inheritMessage = '';
					$checked = (isset($uninheritedCodes[$code]) || isset($inheritedCodes[$code]))
						? ' checked="checked"'
						: '';
					$title = $permission['help']
						? 'title="' . htmlentities($permission['help'], ENT_COMPAT, 'UTF-8') . '" '
						: '';

					if (isset($inheritedCodes[$code])) {
						// disable inherited codes, as any saving logic would be too complicate to express in this
						// interface
						$disabled = ' disabled="true"';
						$inheritMessage = ' (' . join(', ', $inheritedCodes[$code]) . ')';
					} elseif($this->records && $this->records->Count() > 1 && isset($uninheritedCodes[$code])) {
						// If code assignments are collected from more than one "source group",
						// show its origin automatically
						$inheritMessage = ' (' . join(', ', $uninheritedCodes[$code]).')';
					}

					// Disallow modification of "privileged" permissions unless currently logged-in user is an admin
					if(!Permission::check('ADMIN') && in_array($code, $privilegedPermissions)) {
						$disabled = ' disabled="true"';
					}

					// If the field is readonly, always mark as "disabled"
					if($this->readonly) $disabled = ' disabled="true"';

					$inheritMessage = '<small>' . $inheritMessage . '</small>';
					$icon = ($checked) ? 'accept' : 'decline';

					// If the field is readonly, add a span that will replace the disabled checkbox input
					if($this->readonly) {
						$options .= "<li class=\"$extraClass\">"
							. "<input id=\"$itemID\"$disabled name=\"$this->name[$code]\" type=\"checkbox\""
							. " value=\"$code\"$checked class=\"checkbox\" />"
							. "<label {$title}for=\"$itemID\">"
							. "<span class=\"ui-button-icon-primary ui-icon btn-icon-$icon\"></span>"
							. "$value$inheritMessage</label>"
							. "</li>\n";
					} else {
						$options .= "<li class=\"$extraClass\">"
							. "<input id=\"$itemID\"$disabled name=\"$this->name[$code]\" type=\"checkbox\""
							. " value=\"$code\"$checked class=\"checkbox\" />"
							. "<label {$title}for=\"$itemID\">$value$inheritMessage</label>"
							. "</li>\n";
					}
				}
			}
		}
		if($this->readonly) {
			return
				"<ul id=\"{$this->ID()}\" class=\"optionset checkboxsetfield{$this->extraClass()}\">\n" .
				"<li class=\"help\">" .
				_t(
					'Permissions.UserPermissionsIntro',
					'Assigning groups to this user will adjust the permissions they have.'
					. ' See the groups section for details of permissions on individual groups.'
				) .
				"</li>" .
				$options .
				"</ul>\n";
		} else {
			return
			    "<ul id=\"{$this->ID()}\" class=\"optionset checkboxsetfield{$this->extraClass()}\">\n" .
				$options .
				"</ul>\n";
		}
	}

	/**
	 * Update the permission set associated with $record DataObject
	 *
	 * @param DataObjectInterface $record
	 */
	public function saveInto(DataObjectInterface $record) {
		$fieldname = $this->name;
		$managedClass = $this->managedClass;

		// Remove all "privileged" permissions if the currently logged-in user is not an admin
		$privilegedPermissions = Permission::config()->privileged_permissions;
		if(!Permission::check('ADMIN')) {
			foreach($this->value as $id => $bool) {
				if(in_array($id, $privilegedPermissions)) {
					unset($this->value[$id]);
				}
			}
		}

		// remove all permissions and re-add them afterwards
		$permissions = $record->$fieldname();
		foreach ( $permissions as $permission ) {
			$permission->delete();
		}

		$schema = DataObject::getSchema();
		if($fieldname && $record && (
			$schema->hasManyComponent(get_class($record), $fieldname)
			|| $schema->manyManyComponent(get_class($record), $fieldname)
		)) {

			if(!$record->ID) $record->write(); // We need a record ID to write permissions

			if($this->value) {
				foreach($this->value as $id => $bool) {
					if($bool) {
						$perm = new $managedClass();
						$perm->{$this->filterField} = $record->ID;
						$perm->Code = $id;
						$perm->write();
					}
				}
			}
		}
	}

	/**
	 * @return PermissionCheckboxSetField_Readonly
	 */
	public function performReadonlyTransformation() {
		$readonly = new PermissionCheckboxSetField_Readonly(
			$this->name,
			$this->title,
			$this->managedClass,
			$this->filterField,
			$this->records
		);

		return $readonly;
	}
}