// Copyright 2017 Andrew Morgan <andrew@amorgan.xyz>
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package routing

import (
	"regexp"
	"testing"

	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
	"github.com/matrix-org/dendrite/setup/config"
)

var (
	// Registration Flows that the server allows.
	allowedFlows = []authtypes.Flow{
		{
			Stages: []authtypes.LoginType{
				authtypes.LoginType("stage1"),
				authtypes.LoginType("stage2"),
			},
		},
		{
			Stages: []authtypes.LoginType{
				authtypes.LoginType("stage1"),
				authtypes.LoginType("stage3"),
			},
		},
	}
)

// Should return true as we're completing all the stages of a single flow in
// order.
func TestFlowCheckingCompleteFlowOrdered(t *testing.T) {
	testFlow := []authtypes.LoginType{
		authtypes.LoginType("stage1"),
		authtypes.LoginType("stage3"),
	}

	if !checkFlowCompleted(testFlow, allowedFlows) {
		t.Error("Incorrect registration flow verification: ", testFlow, ", from allowed flows: ", allowedFlows, ". Should be true.")
	}
}

// Should return false as all stages in a single flow need to be completed.
func TestFlowCheckingStagesFromDifferentFlows(t *testing.T) {
	testFlow := []authtypes.LoginType{
		authtypes.LoginType("stage2"),
		authtypes.LoginType("stage3"),
	}

	if checkFlowCompleted(testFlow, allowedFlows) {
		t.Error("Incorrect registration flow verification: ", testFlow, ", from allowed flows: ", allowedFlows, ". Should be false.")
	}
}

// Should return true as we're completing all the stages from a single flow, as
// well as some extraneous stages.
func TestFlowCheckingCompleteOrderedExtraneous(t *testing.T) {
	testFlow := []authtypes.LoginType{
		authtypes.LoginType("stage1"),
		authtypes.LoginType("stage3"),
		authtypes.LoginType("stage4"),
		authtypes.LoginType("stage5"),
	}
	if !checkFlowCompleted(testFlow, allowedFlows) {
		t.Error("Incorrect registration flow verification: ", testFlow, ", from allowed flows: ", allowedFlows, ". Should be true.")
	}
}

// Should return false as we're submitting an empty flow.
func TestFlowCheckingEmptyFlow(t *testing.T) {
	testFlow := []authtypes.LoginType{}
	if checkFlowCompleted(testFlow, allowedFlows) {
		t.Error("Incorrect registration flow verification: ", testFlow, ", from allowed flows: ", allowedFlows, ". Should be false.")
	}
}

// Should return false as we've completed a stage that isn't in any allowed flow.
func TestFlowCheckingInvalidStage(t *testing.T) {
	testFlow := []authtypes.LoginType{
		authtypes.LoginType("stage8"),
	}
	if checkFlowCompleted(testFlow, allowedFlows) {
		t.Error("Incorrect registration flow verification: ", testFlow, ", from allowed flows: ", allowedFlows, ". Should be false.")
	}
}

// Should return true as we complete all stages of an allowed flow, though out
// of order, as well as extraneous stages.
func TestFlowCheckingExtraneousUnordered(t *testing.T) {
	testFlow := []authtypes.LoginType{
		authtypes.LoginType("stage5"),
		authtypes.LoginType("stage4"),
		authtypes.LoginType("stage3"),
		authtypes.LoginType("stage2"),
		authtypes.LoginType("stage1"),
	}
	if !checkFlowCompleted(testFlow, allowedFlows) {
		t.Error("Incorrect registration flow verification: ", testFlow, ", from allowed flows: ", allowedFlows, ". Should be true.")
	}
}

// Should return false as we're providing fewer stages than are required.
func TestFlowCheckingShortIncorrectInput(t *testing.T) {
	testFlow := []authtypes.LoginType{
		authtypes.LoginType("stage8"),
	}
	if checkFlowCompleted(testFlow, allowedFlows) {
		t.Error("Incorrect registration flow verification: ", testFlow, ", from allowed flows: ", allowedFlows, ". Should be false.")
	}
}

// Should return false as we're providing different stages than are required.
func TestFlowCheckingExtraneousIncorrectInput(t *testing.T) {
	testFlow := []authtypes.LoginType{
		authtypes.LoginType("stage8"),
		authtypes.LoginType("stage9"),
		authtypes.LoginType("stage10"),
		authtypes.LoginType("stage11"),
	}
	if checkFlowCompleted(testFlow, allowedFlows) {
		t.Error("Incorrect registration flow verification: ", testFlow, ", from allowed flows: ", allowedFlows, ". Should be false.")
	}
}

// Completed flows stages should always be a valid slice header.
// TestEmptyCompletedFlows checks that sessionsDict returns a slice & not nil.
func TestEmptyCompletedFlows(t *testing.T) {
	fakeEmptySessions := newSessionsDict()
	fakeSessionID := "aRandomSessionIDWhichDoesNotExist"
	ret := fakeEmptySessions.GetCompletedStages(fakeSessionID)

	// check for []
	if ret == nil || len(ret) != 0 {
		t.Error("Empty Completed Flow Stages should be a empty slice: returned ", ret, ". Should be []")
	}
}

// This method tests validation of the provided Application Service token and
// username that they're registering
func TestValidationOfApplicationServices(t *testing.T) {
	// Set up application service namespaces
	regex := "@_appservice_.*"
	regexp, err := regexp.Compile(regex)
	if err != nil {
		t.Errorf("Error compiling regex: %s", regex)
	}

	fakeNamespace := config.ApplicationServiceNamespace{
		Exclusive:    true,
		Regex:        regex,
		RegexpObject: regexp,
	}

	// Create a fake application service
	fakeID := "FakeAS"
	fakeSenderLocalpart := "_appservice_bot"
	fakeApplicationService := config.ApplicationService{
		ID:              fakeID,
		URL:             "null",
		ASToken:         "1234",
		HSToken:         "4321",
		SenderLocalpart: fakeSenderLocalpart,
		NamespaceMap: map[string][]config.ApplicationServiceNamespace{
			"users": {fakeNamespace},
		},
	}

	// Set up a config
	fakeConfig := &config.Dendrite{}
	fakeConfig.Defaults()
	fakeConfig.Global.ServerName = "localhost"
	fakeConfig.ClientAPI.Derived.ApplicationServices = []config.ApplicationService{fakeApplicationService}

	// Access token is correct, user_id omitted so we are acting as SenderLocalpart
	asID, resp := validateApplicationService(&fakeConfig.ClientAPI, fakeSenderLocalpart, "1234")
	if resp != nil || asID != fakeID {
		t.Errorf("appservice should have validated and returned correct ID: %s", resp.JSON)
	}

	// Access token is incorrect, user_id omitted so we are acting as SenderLocalpart
	asID, resp = validateApplicationService(&fakeConfig.ClientAPI, fakeSenderLocalpart, "xxxx")
	if resp == nil || asID == fakeID {
		t.Errorf("access_token should have been marked as invalid")
	}

	// Access token is correct, acting as valid user_id
	asID, resp = validateApplicationService(&fakeConfig.ClientAPI, "_appservice_bob", "1234")
	if resp != nil || asID != fakeID {
		t.Errorf("access_token and user_id should've been valid: %s", resp.JSON)
	}

	// Access token is correct, acting as invalid user_id
	asID, resp = validateApplicationService(&fakeConfig.ClientAPI, "_something_else", "1234")
	if resp == nil || asID == fakeID {
		t.Errorf("user_id should not have been valid: @_something_else:localhost")
	}
}
