/*
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 gce

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"

	computealpha "google.golang.org/api/compute/v0.alpha"
	computebeta "google.golang.org/api/compute/v0.beta"
	compute "google.golang.org/api/compute/v1"
)

// test

type FakeCloudAddressService struct {
	count int
	// reservedAddrs tracks usage of IP addresses
	// Key is the IP address as a string
	reservedAddrs map[string]bool
	// addrsByRegionAndName
	// Outer key is for region string; inner key is for address name.
	addrsByRegionAndName map[string]map[string]*computealpha.Address
}

// FakeCloudAddressService Implements CloudAddressService
var _ CloudAddressService = &FakeCloudAddressService{}

func NewFakeCloudAddressService() *FakeCloudAddressService {
	return &FakeCloudAddressService{
		reservedAddrs:        make(map[string]bool),
		addrsByRegionAndName: make(map[string]map[string]*computealpha.Address),
	}
}

// SetRegionalAddresses sets the addresses of ther region. This is used for
// setting the test environment.
func (cas *FakeCloudAddressService) SetRegionalAddresses(region string, addrs []*computealpha.Address) {
	// Reset addresses in the region.
	cas.addrsByRegionAndName[region] = make(map[string]*computealpha.Address)

	for _, addr := range addrs {
		cas.reservedAddrs[addr.Address] = true
		cas.addrsByRegionAndName[region][addr.Name] = addr
	}
}

func (cas *FakeCloudAddressService) ReserveAlphaRegionAddress(addr *computealpha.Address, region string) error {
	if addr.Address == "" {
		addr.Address = fmt.Sprintf("1.2.3.%d", cas.count)
		cas.count++
	}

	if addr.AddressType == "" {
		addr.AddressType = string(schemeExternal)
	}

	if cas.reservedAddrs[addr.Address] {
		msg := "IP in use"
		// When the IP is already in use, this call returns an error code based
		// on the type (internal vs external) of the address. This is to be
		// consistent with actual GCE API.
		switch lbScheme(addr.AddressType) {
		case schemeExternal:
			return makeGoogleAPIError(http.StatusBadRequest, msg)
		default:
			return makeGoogleAPIError(http.StatusConflict, msg)
		}
	}

	if _, exists := cas.addrsByRegionAndName[region]; !exists {
		cas.addrsByRegionAndName[region] = make(map[string]*computealpha.Address)
	}

	if _, exists := cas.addrsByRegionAndName[region][addr.Name]; exists {
		return makeGoogleAPIError(http.StatusConflict, "name in use")
	}

	cas.addrsByRegionAndName[region][addr.Name] = addr
	cas.reservedAddrs[addr.Address] = true
	return nil
}

func (cas *FakeCloudAddressService) ReserveBetaRegionAddress(addr *computebeta.Address, region string) error {
	alphaAddr := convertToAlphaAddress(addr)
	return cas.ReserveAlphaRegionAddress(alphaAddr, region)
}

func (cas *FakeCloudAddressService) ReserveRegionAddress(addr *compute.Address, region string) error {
	alphaAddr := convertToAlphaAddress(addr)
	return cas.ReserveAlphaRegionAddress(alphaAddr, region)
}

func (cas *FakeCloudAddressService) GetAlphaRegionAddress(name, region string) (*computealpha.Address, error) {
	if _, exists := cas.addrsByRegionAndName[region]; !exists {
		return nil, makeGoogleAPINotFoundError("")
	}

	if addr, exists := cas.addrsByRegionAndName[region][name]; !exists {
		return nil, makeGoogleAPINotFoundError("")
	} else {
		return addr, nil
	}
}

func (cas *FakeCloudAddressService) GetBetaRegionAddress(name, region string) (*computebeta.Address, error) {
	addr, err := cas.GetAlphaRegionAddress(name, region)
	if addr != nil {
		return convertToBetaAddress(addr), err
	}
	return nil, err
}

func (cas *FakeCloudAddressService) GetRegionAddress(name, region string) (*compute.Address, error) {
	addr, err := cas.GetAlphaRegionAddress(name, region)
	if addr != nil {
		return convertToV1Address(addr), err
	}
	return nil, err
}

func (cas *FakeCloudAddressService) DeleteRegionAddress(name, region string) error {
	if _, exists := cas.addrsByRegionAndName[region]; !exists {
		return makeGoogleAPINotFoundError("")
	}

	addr, exists := cas.addrsByRegionAndName[region][name]
	if !exists {
		return makeGoogleAPINotFoundError("")
	}

	delete(cas.reservedAddrs, addr.Address)
	delete(cas.addrsByRegionAndName[region], name)
	return nil
}

func (cas *FakeCloudAddressService) GetAlphaRegionAddressByIP(region, ipAddress string) (*computealpha.Address, error) {
	if _, exists := cas.addrsByRegionAndName[region]; !exists {
		return nil, makeGoogleAPINotFoundError("")
	}

	for _, addr := range cas.addrsByRegionAndName[region] {
		if addr.Address == ipAddress {
			return addr, nil
		}
	}
	return nil, makeGoogleAPINotFoundError("")
}

func (cas *FakeCloudAddressService) GetBetaRegionAddressByIP(name, region string) (*computebeta.Address, error) {
	addr, err := cas.GetAlphaRegionAddressByIP(name, region)
	if addr != nil {
		return convertToBetaAddress(addr), nil
	}
	return nil, err
}

func (cas *FakeCloudAddressService) GetRegionAddressByIP(name, region string) (*compute.Address, error) {
	addr, err := cas.GetAlphaRegionAddressByIP(name, region)
	if addr != nil {
		return convertToV1Address(addr), nil
	}
	return nil, err
}

func (cas *FakeCloudAddressService) getNetworkTierFromAddress(name, region string) (string, error) {
	addr, err := cas.GetAlphaRegionAddress(name, region)
	if err != nil {
		return "", err
	}
	return addr.NetworkTier, nil
}

func convertToV1Address(object gceObject) *compute.Address {
	enc, err := object.MarshalJSON()
	if err != nil {
		panic(fmt.Sprintf("Failed to encode to json: %v", err))
	}
	var addr compute.Address
	if err := json.Unmarshal(enc, &addr); err != nil {
		panic(fmt.Sprintf("Failed to convert GCE apiObject %v to v1 address: %v", object, err))
	}
	return &addr
}

func convertToAlphaAddress(object gceObject) *computealpha.Address {
	enc, err := object.MarshalJSON()
	if err != nil {
		panic(fmt.Sprintf("Failed to encode to json: %v", err))
	}
	var addr computealpha.Address
	if err := json.Unmarshal(enc, &addr); err != nil {
		panic(fmt.Sprintf("Failed to convert GCE apiObject %v to alpha address: %v", object, err))
	}
	// Set the default values for the Alpha fields.
	addr.NetworkTier = NetworkTierDefault.ToGCEValue()
	return &addr
}

func convertToBetaAddress(object gceObject) *computebeta.Address {
	enc, err := object.MarshalJSON()
	if err != nil {
		panic(fmt.Sprintf("Failed to encode to json: %v", err))
	}
	var addr computebeta.Address
	if err := json.Unmarshal(enc, &addr); err != nil {
		panic(fmt.Sprintf("Failed to convert GCE apiObject %v to beta address: %v", object, err))
	}
	return &addr
}

func (cas *FakeCloudAddressService) String() string {
	var b bytes.Buffer
	for region, regAddresses := range cas.addrsByRegionAndName {
		b.WriteString(fmt.Sprintf("%v:\n", region))
		for name, addr := range regAddresses {
			b.WriteString(fmt.Sprintf(" %v:  %v\n", name, addr.Address))
		}
	}
	return b.String()
}