[MM-61756] Attribute Based Access Control - Phase 1 (#30785)

Attribute Based Access Control - Base
* MM-63662

* MM-63919

* MM-63954

* MM-63955 

* MM-63425

* MM-63426

* MM-63458

* MM-63459

* MM-63603

* MM-63845

* MM-64146

* MM-64199

* MM-64201

* MM-64233

* MM-64247

* MM-64268

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Co-authored-by: Harshil Sharma <harshilsharma63@gmail.com>
Co-authored-by: Pablo Andrés Vélez Vidal <pablovv2012@gmail.com>
Co-authored-by: abhijit-singh <abhijitsingh0702@gmail.com>
Co-authored-by: Harrison Healey <harrisonmhealey@gmail.com>

server/einterfaces/pap.go

@@ -0,0 +1,42 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package einterfaces
+
+import (
+	"github.com/mattermost/mattermost/server/public/model"
+	"github.com/mattermost/mattermost/server/public/shared/request"
+)
+
+// PolicyAdministrationPointInterface is the service that manages access control policies.
+// It is responsible for creating, updating, and deleting policies.
+// Also, it provides methods to check the validity of expressions and to retrieve policies.
+type PolicyAdministrationPointInterface interface {
+	// Init initializes the policy administration point and intiates the CEL engine.
+	// It is an idempotent operation, meaning that it can be called multiple times.
+	Init(rctx request.CTX) *model.AppError
+	// GetPolicyRuleAttributes retrieves the attributes of the given policy.
+	// It returns a map of attribute names to their values for given action.
+	GetPolicyRuleAttributes(rctx request.CTX, policyID string, action string) (map[string][]string, *model.AppError)
+	// CheckExpression checks the validity of the given expression using the CEL engine.
+	// It returns a list of CELExpressionError if the expression is invalid.
+	// If the expression is valid, it returns an empty list.
+	CheckExpression(rctx request.CTX, expression string) ([]model.CELExpressionError, *model.AppError)
+	// ExpressionToVisualAST converts the given expression to a visual AST.
+	ExpressionToVisualAST(rctx request.CTX, expression string) (*model.VisualExpression, *model.AppError)
+	// NormalizePolicy normalizes the given policy by restoring ids back to names.
+	NormalizePolicy(rctx request.CTX, policy *model.AccessControlPolicy) (*model.AccessControlPolicy, *model.AppError)
+	// QueryUsersForExpression evaluates the given expression using the CEL engine.
+	// It returns a list of users that match the expression.
+	QueryUsersForExpression(rctx request.CTX, expression string, opts model.SubjectSearchOptions) ([]*model.User, int64, *model.AppError)
+	// QueryUsersForResource evaluates finds the users match to the resource.
+	QueryUsersForResource(rctx request.CTX, resourceID, action string, opts model.SubjectSearchOptions) ([]*model.User, int64, *model.AppError)
+	// GetChannelMembersToRemove retrieves the channel members that need to be removed from the given channel.
+	GetChannelMembersToRemove(rctx request.CTX, channelID string) ([]*model.ChannelMember, *model.AppError)
+	// SavePolicy saves the given access control policy.
+	SavePolicy(rctx request.CTX, policy *model.AccessControlPolicy) (*model.AccessControlPolicy, *model.AppError)
+	// GetPolicy retrieves the access control policy with the given ID.
+	GetPolicy(rctx request.CTX, id string) (*model.AccessControlPolicy, *model.AppError)
+	// DeletePolicy deletes the access control policy with the given ID.
+	DeletePolicy(rctx request.CTX, id string) *model.AppError
+}