//
// Copyright (c) 2018
// Mainflux
//
// SPDX-License-Identifier: Apache-2.0
//

package postgres_test

import (
	"fmt"
	"testing"

	"github.com/stretchr/testify/require"

	"github.com/mainflux/mainflux/things"
	"github.com/mainflux/mainflux/things/postgres"
	"github.com/mainflux/mainflux/things/uuid"
	"github.com/stretchr/testify/assert"
)

func TestChannelSave(t *testing.T) {
	email := "channel-save@example.com"
	channelRepo := postgres.NewChannelRepository(db, testLog)

	channel := things.Channel{Owner: email}

	cases := []struct {
		desc    string
		channel things.Channel
		err     error
	}{
		{
			desc:    "create valid channel",
			channel: channel,
			err:     nil,
		},
		{
			desc:    "create invalid channel",
			channel: things.Channel{Owner: email, Metadata: "invalid"},
			err:     things.ErrMalformedEntity,
		},
	}

	for _, tc := range cases {
		_, err := channelRepo.Save(tc.channel)
		assert.Equal(t, tc.err, err, fmt.Sprintf("%s: expected %s got %s\n", tc.desc, tc.err, err))
	}
}

func TestChannelUpdate(t *testing.T) {
	email := "channel-update@example.com"
	chanRepo := postgres.NewChannelRepository(db, testLog)

	c := things.Channel{Owner: email}
	id, _ := chanRepo.Save(c)
	c.ID = id

	cases := []struct {
		desc    string
		channel things.Channel
		err     error
	}{
		{
			desc:    "update existing channel",
			channel: c,
			err:     nil,
		},
		{
			desc:    "update channel with invalid data",
			channel: things.Channel{Owner: email, Metadata: "invalid"},
			err:     things.ErrMalformedEntity,
		},
		{
			desc:    "update non-existing channel with existing user",
			channel: things.Channel{ID: wrongID, Owner: email},
			err:     things.ErrNotFound,
		},
		{
			desc:    "update existing channel ID with non-existing user",
			channel: things.Channel{ID: c.ID, Owner: wrongValue},
			err:     things.ErrNotFound,
		},
		{
			desc:    "update non-existing channel with non-existing user",
			channel: things.Channel{ID: wrongID, Owner: wrongValue},
			err:     things.ErrNotFound,
		},
	}

	for _, tc := range cases {
		err := chanRepo.Update(tc.channel)
		assert.Equal(t, tc.err, err, fmt.Sprintf("%s: expected %s got %s\n", tc.desc, tc.err, err))
	}
}

func TestSingleChannelRetrieval(t *testing.T) {
	email := "channel-single-retrieval@example.com"
	chanRepo := postgres.NewChannelRepository(db, testLog)
	thingRepo := postgres.NewThingRepository(db, testLog)

	th := things.Thing{
		Owner: email,
		Key:   uuid.New().ID(),
	}
	th.ID, _ = thingRepo.Save(th)

	c := things.Channel{
		Owner:  email,
		Things: []things.Thing{th},
	}

	c.ID, _ = chanRepo.Save(c)
	chanRepo.Connect(email, c.ID, th.ID)

	cases := map[string]struct {
		owner string
		ID    uint64
		err   error
	}{
		"retrieve channel with existing user": {
			owner: c.Owner,
			ID:    c.ID,
			err:   nil,
		},
		"retrieve channel with existing user, non-existing channel": {
			owner: c.Owner,
			ID:    wrongID,
			err:   things.ErrNotFound,
		},
		"retrieve channel with non-existing owner": {
			owner: wrongValue,
			ID:    c.ID,
			err:   things.ErrNotFound,
		},
	}

	for desc, tc := range cases {
		_, err := chanRepo.RetrieveByID(tc.owner, tc.ID)
		assert.Equal(t, tc.err, err, fmt.Sprintf("%s: expected %s got %s\n", desc, tc.err, err))
	}
}

func TestMultiChannelRetrieval(t *testing.T) {
	email := "channel-multi-retrieval@example.com"
	chanRepo := postgres.NewChannelRepository(db, testLog)

	n := uint64(10)

	for i := uint64(0); i < n; i++ {
		c := things.Channel{Owner: email}
		chanRepo.Save(c)
	}

	cases := map[string]struct {
		owner  string
		offset uint64
		limit  uint64
		size   uint64
	}{
		"retrieve all channels with existing owner": {
			owner:  email,
			offset: 0,
			limit:  n,
			size:   n,
		},
		"retrieve subset of channels with existing owner": {
			owner:  email,
			offset: n / 2,
			limit:  n,
			size:   n / 2,
		},
		"retrieve channels with non-existing owner": {
			owner:  wrongValue,
			offset: n / 2,
			limit:  n,
			size:   0,
		},
	}

	for desc, tc := range cases {
		result := chanRepo.RetrieveAll(tc.owner, tc.offset, tc.limit)
		size := uint64(len(result))
		assert.Equal(t, tc.size, size, fmt.Sprintf("%s: expected %d got %d\n", desc, tc.size, size))
	}
}

func TestChannelRemoval(t *testing.T) {
	email := "channel-removal@example.com"
	chanRepo := postgres.NewChannelRepository(db, testLog)
	chanID, _ := chanRepo.Save(things.Channel{Owner: email})

	// show that the removal works the same for both existing and non-existing
	// (removed) channel
	for i := 0; i < 2; i++ {
		err := chanRepo.Remove(email, chanID)
		require.Nil(t, err, fmt.Sprintf("#%d: failed to remove channel due to: %s", i, err))

		_, err = chanRepo.RetrieveByID(email, chanID)
		require.Equal(t, things.ErrNotFound, err, fmt.Sprintf("#%d: expected %s got %s", i, things.ErrNotFound, err))
	}
}

func TestConnect(t *testing.T) {
	email := "channel-connect@example.com"
	thingRepo := postgres.NewThingRepository(db, testLog)

	thing := things.Thing{
		Owner:    email,
		Key:      uuid.New().ID(),
		Metadata: "{}",
	}
	thingID, _ := thingRepo.Save(thing)

	chanRepo := postgres.NewChannelRepository(db, testLog)
	chanID, _ := chanRepo.Save(things.Channel{Owner: email})

	cases := []struct {
		desc    string
		owner   string
		chanID  uint64
		thingID uint64
		err     error
	}{
		{
			desc:    "connect existing user, channel and thing",
			owner:   email,
			chanID:  chanID,
			thingID: thingID,
			err:     nil,
		},
		{
			desc:    "connect connected channel and thing",
			owner:   email,
			chanID:  chanID,
			thingID: thingID,
			err:     nil,
		},
		{
			desc:    "connect with non-existing user",
			owner:   wrongValue,
			chanID:  chanID,
			thingID: thingID,
			err:     things.ErrNotFound,
		},
		{
			desc:    "connect non-existing channel",
			owner:   email,
			chanID:  wrongID,
			thingID: thingID,
			err:     things.ErrNotFound,
		},
		{
			desc:    "connect non-existing thing",
			owner:   email,
			chanID:  chanID,
			thingID: wrongID,
			err:     things.ErrNotFound,
		},
	}

	for _, tc := range cases {
		err := chanRepo.Connect(tc.owner, tc.chanID, tc.thingID)
		assert.Equal(t, tc.err, err, fmt.Sprintf("%s: expected %s got %s\n", tc.desc, tc.err, err))
	}
}

func TestDisconnect(t *testing.T) {
	email := "channel-disconnect@example.com"
	thingRepo := postgres.NewThingRepository(db, testLog)
	thing := things.Thing{
		Owner:    email,
		Key:      uuid.New().ID(),
		Metadata: "{}",
	}
	thingID, _ := thingRepo.Save(thing)

	chanRepo := postgres.NewChannelRepository(db, testLog)
	chanID, _ := chanRepo.Save(things.Channel{Owner: email})
	chanRepo.Connect(email, chanID, thingID)

	cases := []struct {
		desc    string
		owner   string
		chanID  uint64
		thingID uint64
		err     error
	}{
		{
			desc:    "disconnect connected thing",
			owner:   email,
			chanID:  chanID,
			thingID: thingID,
			err:     nil,
		},
		{
			desc:    "disconnect non-connected thing",
			owner:   email,
			chanID:  chanID,
			thingID: thingID,
			err:     things.ErrNotFound,
		},
		{
			desc:    "disconnect non-existing user",
			owner:   wrongValue,
			chanID:  chanID,
			thingID: thingID,
			err:     things.ErrNotFound,
		},
		{
			desc:    "disconnect non-existing channel",
			owner:   email,
			chanID:  wrongID,
			thingID: thingID,
			err:     things.ErrNotFound,
		},
		{
			desc:    "disconnect non-existing thing",
			owner:   email,
			chanID:  chanID,
			thingID: wrongID,
			err:     things.ErrNotFound,
		},
	}

	for _, tc := range cases {
		err := chanRepo.Disconnect(tc.owner, tc.chanID, tc.thingID)
		assert.Equal(t, tc.err, err, fmt.Sprintf("%s: expected %s got %s\n", tc.desc, tc.err, err))
	}
}

func TestHasThing(t *testing.T) {
	email := "channel-access-check@example.com"
	thingRepo := postgres.NewThingRepository(db, testLog)
	thing := things.Thing{
		Owner: email,
		Key:   uuid.New().ID(),
	}
	thingID, _ := thingRepo.Save(thing)

	chanRepo := postgres.NewChannelRepository(db, testLog)
	chanID, _ := chanRepo.Save(things.Channel{Owner: email})
	chanRepo.Connect(email, chanID, thingID)

	cases := map[string]struct {
		chanID    uint64
		key       string
		hasAccess bool
	}{
		"access check for thing that has access": {
			chanID:    chanID,
			key:       thing.Key,
			hasAccess: true,
		},
		"access check for thing without access": {
			chanID:    chanID,
			key:       wrongValue,
			hasAccess: false,
		},
		"access check for non-existing channel": {
			chanID:    wrongID,
			key:       thing.Key,
			hasAccess: false,
		},
	}

	for desc, tc := range cases {
		_, err := chanRepo.HasThing(tc.chanID, tc.key)
		hasAccess := err == nil
		assert.Equal(t, tc.hasAccess, hasAccess, fmt.Sprintf("%s: expected %t got %t\n", desc, tc.hasAccess, hasAccess))
	}
}