// 2020 Rackspace, Inc.
//
// 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 dpfailover will assign CORE failover devices based on myadmin
package dpfailover

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"strings"
	"time"

	"github.com/labstack/gommon/color"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
	"github.rackspace.com/DCM/gomigrate/shared"
	"github.rackspace.com/DCM/migration/pkg/audit/failover"
	"github.rackspace.com/DCM/tools"

	"github.rackspace.com/gorax/gokeys"
)

type (
	// Client contains all the data types needed to
	// initialize and use this package.
	Client struct {
		coreToken     string
		identityToken string
	}
)

// pluginFunc function is executed from the gomigrate caller
func pluginFunc(cfg gokeys.Settings) {
	c := initCfg(cfg)
	devices, err := c.GatherFirewallsAndLBs()
	if err != nil {
		logrus.Fatal(err)
	}
	for _, d := range devices {
		res, err := c.CoreFailoverAPI(d)
		if err != nil {
			logrus.Errorf("[%s]: %s", color.Yellow(d.ID), color.Red(err))
			continue
		}
		msg := res.Data.Message
		if strings.Contains(res.Data.Message, " assigned successfully") {
			msg = color.Green(res.Data.Message)
		}
		logrus.Infof("[%s]: %s", color.Yellow(d.ID), msg)
	}
}

// GatherFirewallsAndLBs will fetch devices from the migration DB and filter out only the
// network devices we care about.
func (c *Client) GatherFirewallsAndLBs() ([]tools.Device, error) {
	r := make([]tools.Device, 0)
	devices, err := shared.MongoDevices(*argM, nil, *argD, "", c.coreToken, make(map[string]interface{}))
	if err != nil {
		return r, err
	}

	for _, d := range devices {
		if strings.Contains(strings.ToLower(d.Device.MakeModel), "load-balancer") {
			r = append(r, d)
			continue
		}
		if strings.Contains(strings.ToLower(d.Device.MakeModel), "cisco asa") {
			r = append(r, d)
			continue
		}
		if strings.Contains(strings.ToLower(d.Device.MakeModel), "firewall - cisco") {
			r = append(r, d)
			continue
		}
		if strings.Contains(strings.ToLower(d.Device.MakeModel), "firewall - palo alto") {
			r = append(r, d)
			continue
		}
	}
	return r, nil
}

// CoreFailoverAPIResult is the response received back from the /core_failover api
type CoreFailoverAPIResult struct {
	Data  failover.Result `json:"data"`
	Error string          `json:"error"`
}

// CoreFailoverAPI function will call the migration.nsi.rackspace.com/core_failover call to
// assign or reassign the failover device for net-devices.
func (c *Client) CoreFailoverAPI(d tools.Device) (CoreFailoverAPIResult, error) {
	var (
		headers = map[string]string{
			"Accept":       "application/json",
			"Connection":   "close",
			"X-Auth-Token": c.identityToken,
		}
		result  = CoreFailoverAPIResult{}
		fullURL = fmt.Sprintf("%s/core_failover/datapipe/%d", shared.MigAPI, d.ID)
	)

	ctx, cancel := context.WithTimeout(context.Background(), time.Second*120)
	defer cancel()

	// Build the request
	req, err := http.NewRequestWithContext(ctx, http.MethodPut, fullURL, nil)
	if err != nil {
		return result, fmt.Errorf("coreFailoverAPI:NewRequest:%d:%s", d.ID, err)
	}

	for k, v := range headers {
		req.Header.Set(k, v)
	}

	// Send the request via a client
	// Do sends an HTTP request and
	// returns an HTTP response
	r, err := http.DefaultClient.Do(req)
	if err != nil {
		return result, fmt.Errorf("coreFailoverAPI:Do:%d:%s", d.ID, err)
	}

	if r != nil {
		defer func() {
			if defErr := r.Body.Close(); defErr != nil {
				err = errors.Wrap(defErr, "defer error")
			}
		}()
	}

	// Use json.Decode for reading streams of JSON data
	if err := json.NewDecoder(r.Body).Decode(&result); err != nil {
		return result, fmt.Errorf("coreFailoverAPI:Decode:%d:%s", d.ID, err)
	}

	if result.Error != "" {
		return result, errors.New(result.Error)
	}
	return result, nil
}

// initCfg is the initialization method for this package that will populate an
// instance of the Client struct for subsequent calls to its methods.
func initCfg(cfg gokeys.Settings) *Client {
	// Pull an identity token from the users gokeys keychain
	iKey, err := cfg.Identity(false)
	if err != nil {
		logrus.Fatal(err)
	}

	cKey, err := cfg.Core(false)
	if err != nil {
		logrus.Fatal(err)
	}
	return &Client{identityToken: iKey.Password, coreToken: cKey.Password}
}