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

package api

import (
	"context"
	"time"

	"github.com/go-kit/kit/metrics"
	"github.com/mainflux/mainflux"
	mfclients "github.com/mainflux/mainflux/pkg/clients"
	"github.com/mainflux/mainflux/things"
)

var _ things.Service = (*metricsMiddleware)(nil)

type metricsMiddleware struct {
	counter metrics.Counter
	latency metrics.Histogram
	svc     things.Service
}

// MetricsMiddleware returns a new metrics middleware wrapper.
func MetricsMiddleware(svc things.Service, counter metrics.Counter, latency metrics.Histogram) things.Service {
	return &metricsMiddleware{
		counter: counter,
		latency: latency,
		svc:     svc,
	}
}

func (ms *metricsMiddleware) CreateThings(ctx context.Context, token string, clients ...mfclients.Client) ([]mfclients.Client, error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "register_things").Add(1)
		ms.latency.With("method", "register_things").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.CreateThings(ctx, token, clients...)
}

func (ms *metricsMiddleware) ViewClient(ctx context.Context, token, id string) (mfclients.Client, error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "view_thing").Add(1)
		ms.latency.With("method", "view_thing").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.ViewClient(ctx, token, id)
}

func (ms *metricsMiddleware) ListClients(ctx context.Context, token string, reqUserID string, pm mfclients.Page) (mfclients.ClientsPage, error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "list_things").Add(1)
		ms.latency.With("method", "list_things").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.ListClients(ctx, token, reqUserID, pm)
}

func (ms *metricsMiddleware) UpdateClient(ctx context.Context, token string, client mfclients.Client) (mfclients.Client, error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "update_thing_name_and_metadata").Add(1)
		ms.latency.With("method", "update_thing_name_and_metadata").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.UpdateClient(ctx, token, client)
}

func (ms *metricsMiddleware) UpdateClientTags(ctx context.Context, token string, client mfclients.Client) (mfclients.Client, error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "update_thing_tags").Add(1)
		ms.latency.With("method", "update_thing_tags").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.UpdateClientTags(ctx, token, client)
}

func (ms *metricsMiddleware) UpdateClientSecret(ctx context.Context, token, oldSecret, newSecret string) (mfclients.Client, error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "update_thing_secret").Add(1)
		ms.latency.With("method", "update_thing_secret").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.UpdateClientSecret(ctx, token, oldSecret, newSecret)
}

func (ms *metricsMiddleware) UpdateClientOwner(ctx context.Context, token string, client mfclients.Client) (mfclients.Client, error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "update_thing_owner").Add(1)
		ms.latency.With("method", "update_thing_owner").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.UpdateClientOwner(ctx, token, client)
}

func (ms *metricsMiddleware) EnableClient(ctx context.Context, token string, id string) (mfclients.Client, error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "enable_thing").Add(1)
		ms.latency.With("method", "enable_thing").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.EnableClient(ctx, token, id)
}

func (ms *metricsMiddleware) DisableClient(ctx context.Context, token string, id string) (mfclients.Client, error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "disable_thing").Add(1)
		ms.latency.With("method", "disable_thing").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.DisableClient(ctx, token, id)
}

func (ms *metricsMiddleware) ListClientsByGroup(ctx context.Context, token, groupID string, pm mfclients.Page) (mp mfclients.MembersPage, err error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "list_things_by_channel").Add(1)
		ms.latency.With("method", "list_things_by_channel").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.ListClientsByGroup(ctx, token, groupID, pm)
}

func (ms *metricsMiddleware) Identify(ctx context.Context, key string) (string, error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "identify_thing").Add(1)
		ms.latency.With("method", "identify_thing").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.Identify(ctx, key)
}

func (ms *metricsMiddleware) Authorize(ctx context.Context, req *mainflux.AuthorizeReq) (id string, err error) {
	defer func(begin time.Time) {
		ms.counter.With("method", "authorize").Add(1)
		ms.latency.With("method", "authorize").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.Authorize(ctx, req)
}

func (ms *metricsMiddleware) Share(ctx context.Context, token, id string, relation string, userids ...string) error {
	defer func(begin time.Time) {
		ms.counter.With("method", "share").Add(1)
		ms.latency.With("method", "share").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.Share(ctx, token, id, relation, userids...)
}

func (ms *metricsMiddleware) Unshare(ctx context.Context, token, id string, relation string, userids ...string) error {
	defer func(begin time.Time) {
		ms.counter.With("method", "unshare").Add(1)
		ms.latency.With("method", "unshare").Observe(time.Since(begin).Seconds())
	}(time.Now())
	return ms.svc.Unshare(ctx, token, id, relation, userids...)
}