/*
Copyright 2017 The Kubernetes Authors.

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 stats

import (
	"fmt"

	cadvisorapiv2 "github.com/google/cadvisor/info/v2"
	"k8s.io/apimachinery/pkg/types"
	statsapi "k8s.io/kubelet/pkg/apis/stats/v1alpha1"
	"k8s.io/kubernetes/pkg/kubelet/kuberuntime"
	"k8s.io/kubernetes/pkg/volume"
)

type fakeHostStatsProvider struct {
	fakeStats map[string]*volume.Metrics
}

func NewFakeHostStatsProvider() HostStatsProvider {
	return &fakeHostStatsProvider{}
}

func NewFakeHostStatsProviderWithData(fakeStats map[string]*volume.Metrics) HostStatsProvider {
	return &fakeHostStatsProvider{
		fakeStats: fakeStats,
	}
}

func (f *fakeHostStatsProvider) getPodLogStats(podNamespace, podName string, podUID types.UID, rootFsInfo *cadvisorapiv2.FsInfo) (*statsapi.FsStats, error) {
	path := kuberuntime.BuildPodLogsDirectory(podNamespace, podName, podUID)
	if _, found := f.fakeStats[path]; found {
		fmt.Printf("P PATH: %s found\n", path)
	}
	metricsProvider := NewFakeMetricsDu(path, f.fakeStats[path])
	return fakeMetricsProviderToStats(metricsProvider, rootFsInfo)
}

func (f *fakeHostStatsProvider) getPodContainerLogStats(podNamespace, podName string, podUID types.UID, containerName string, rootFsInfo *cadvisorapiv2.FsInfo) (*statsapi.FsStats, error) {
	path := kuberuntime.BuildContainerLogsDirectory(podNamespace, podName, podUID, containerName)
	if _, found := f.fakeStats[path]; found {
		fmt.Printf("C PATH: %s found\n", path)
	}
	metricsProvider := NewFakeMetricsDu(path, f.fakeStats[path])
	return fakeMetricsProviderToStats(metricsProvider, rootFsInfo)
}

func (f *fakeHostStatsProvider) getPodEtcHostsStats(podUID types.UID, rootFsInfo *cadvisorapiv2.FsInfo) (*statsapi.FsStats, error) {
	return nil, fmt.Errorf("not implemented")
}

func fakeMetricsProviderToStats(metricsProvider volume.MetricsProvider, rootFsInfo *cadvisorapiv2.FsInfo) (*statsapi.FsStats, error) {
	hostMetrics, err := metricsProvider.GetMetrics()
	if err != nil {
		return nil, fmt.Errorf("failed to get stats %v", err)
	}
	result := rootFsInfoToFsStats(rootFsInfo)
	usedBytes := uint64(hostMetrics.Used.Value())
	inodesUsed := uint64(hostMetrics.InodesUsed.Value())
	result.UsedBytes = addUsage(result.UsedBytes, &usedBytes)
	result.InodesUsed = addUsage(result.InodesUsed, &inodesUsed)
	result.Time = maxUpdateTime(&result.Time, &hostMetrics.Time)
	return result, nil
}

type fakeMetricsDu struct {
	fakeStats *volume.Metrics
}

func NewFakeMetricsDu(path string, stats *volume.Metrics) volume.MetricsProvider {
	return &fakeMetricsDu{fakeStats: stats}
}

func (f *fakeMetricsDu) GetMetrics() (*volume.Metrics, error) {
	if f.fakeStats == nil {
		return nil, fmt.Errorf("no stats provided")
	}
	return f.fakeStats, nil
}