/*
Copyright 2022 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 civocloud

import (
	"bytes"
	"encoding/json"
	"fmt"
	"strings"
	"time"

	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider/civo/civo-cloud-sdk-go/utils"
)

// Instance represents a virtual server within Civo's infrastructure
type Instance struct {
	ID                       string    `json:"id,omitempty"`
	OpenstackServerID        string    `json:"openstack_server_id,omitempty"`
	Hostname                 string    `json:"hostname,omitempty"`
	ReverseDNS               string    `json:"reverse_dns,omitempty"`
	Size                     string    `json:"size,omitempty"`
	Region                   string    `json:"region,omitempty"`
	NetworkID                string    `json:"network_id,omitempty"`
	PrivateIP                string    `json:"private_ip,omitempty"`
	PublicIP                 string    `json:"public_ip,omitempty"`
	PseudoIP                 string    `json:"pseudo_ip,omitempty"`
	TemplateID               string    `json:"template_id,omitempty"`
	SourceType               string    `json:"source_type,omitempty"`
	SourceID                 string    `json:"source_id,omitempty"`
	SnapshotID               string    `json:"snapshot_id,omitempty"`
	InitialUser              string    `json:"initial_user,omitempty"`
	InitialPassword          string    `json:"initial_password,omitempty"`
	SSHKey                   string    `json:"ssh_key,omitempty"`
	SSHKeyID                 string    `json:"ssh_key_id,omitempty"`
	Status                   string    `json:"status,omitempty"`
	Notes                    string    `json:"notes,omitempty"`
	FirewallID               string    `json:"firewall_id,omitempty"`
	Tags                     []string  `json:"tags,omitempty"`
	CivostatsdToken          string    `json:"civostatsd_token,omitempty"`
	CivostatsdStats          string    `json:"civostatsd_stats,omitempty"`
	CivostatsdStatsPerMinute []string  `json:"civostatsd_stats_per_minute,omitempty"`
	CivostatsdStatsPerHour   []string  `json:"civostatsd_stats_per_hour,omitempty"`
	OpenstackImageID         string    `json:"openstack_image_id,omitempty"`
	RescuePassword           string    `json:"rescue_password,omitempty"`
	VolumeBacked             bool      `json:"volume_backed,omitempty"`
	CPUCores                 int       `json:"cpu_cores,omitempty"`
	RAMMegabytes             int       `json:"ram_mb,omitempty"`
	DiskGigabytes            int       `json:"disk_gb,omitempty"`
	Script                   string    `json:"script,omitempty"`
	CreatedAt                time.Time `json:"created_at,omitempty"`
}

//"cpu_cores":1,"ram_mb":2048,"disk_gb":25

// InstanceConsole represents a link to a webconsole for an instances
type InstanceConsole struct {
	URL string `json:"url"`
}

// PaginatedInstanceList returns a paginated list of Instance object
type PaginatedInstanceList struct {
	Page    int        `json:"page"`
	PerPage int        `json:"per_page"`
	Pages   int        `json:"pages"`
	Items   []Instance `json:"items"`
}

// InstanceConfig describes the parameters for a new instance
// none of the fields are mandatory and will be automatically
// set with default values
type InstanceConfig struct {
	Count            int      `json:"count"`
	Hostname         string   `json:"hostname"`
	ReverseDNS       string   `json:"reverse_dns"`
	Size             string   `json:"size"`
	Region           string   `json:"region"`
	PublicIPRequired string   `json:"public_ip"`
	NetworkID        string   `json:"network_id"`
	TemplateID       string   `json:"template_id"`
	SourceType       string   `json:"source_type"`
	SourceID         string   `json:"source_id"`
	SnapshotID       string   `json:"snapshot_id"`
	InitialUser      string   `json:"initial_user"`
	SSHKeyID         string   `json:"ssh_key_id"`
	Script           string   `json:"script"`
	Tags             []string `json:"-"`
	TagsList         string   `json:"tags"`
	FirewallID       string   `json:"firewall_id"`
}

// ListInstances returns a page of Instances owned by the calling API account
func (c *Client) ListInstances(page int, perPage int) (*PaginatedInstanceList, error) {
	url := "/v2/instances"
	if page != 0 && perPage != 0 {
		url = url + fmt.Sprintf("?page=%d&per_page=%d", page, perPage)
	}

	resp, err := c.SendGetRequest(url)
	if err != nil {
		return nil, decodeError(err)
	}

	PaginatedInstances := PaginatedInstanceList{}
	err = json.NewDecoder(bytes.NewReader(resp)).Decode(&PaginatedInstances)
	return &PaginatedInstances, err
}

// ListAllInstances returns all (well, upto 99,999,999 instances) Instances owned by the calling API account
func (c *Client) ListAllInstances() ([]Instance, error) {
	instances, err := c.ListInstances(1, 99999999)
	if err != nil {
		return []Instance{}, decodeError(err)
	}

	return instances.Items, nil
}

// FindInstance finds a instance by either part of the ID or part of the hostname
func (c *Client) FindInstance(search string) (*Instance, error) {
	instances, err := c.ListAllInstances()
	if err != nil {
		return nil, decodeError(err)
	}

	exactMatch := false
	partialMatchesCount := 0
	result := Instance{}

	for _, value := range instances {
		if value.Hostname == search || value.ID == search {
			exactMatch = true
			result = value
		} else if strings.Contains(value.Hostname, search) || strings.Contains(value.ID, search) {
			if !exactMatch {
				result = value
				partialMatchesCount++
			}
		}
	}

	if exactMatch || partialMatchesCount == 1 {
		return &result, nil
	} else if partialMatchesCount > 1 {
		err := fmt.Errorf("unable to find %s because there were multiple matches", search)
		return nil, MultipleMatchesError.wrap(err)
	} else {
		err := fmt.Errorf("unable to find %s, zero matches", search)
		return nil, ZeroMatchesError.wrap(err)
	}
}

// GetInstance returns a single Instance by its full ID
func (c *Client) GetInstance(id string) (*Instance, error) {
	resp, err := c.SendGetRequest("/v2/instances/" + id)
	if err != nil {
		return nil, decodeError(err)
	}

	instance := Instance{}
	err = json.NewDecoder(bytes.NewReader(resp)).Decode(&instance)
	return &instance, err
}

// NewInstanceConfig returns an initialized config for a new instance
func (c *Client) NewInstanceConfig() (*InstanceConfig, error) {
	network, err := c.GetDefaultNetwork()
	if err != nil {
		return nil, decodeError(err)
	}

	diskimage, err := c.GetDiskImageByName("ubuntu-focal")
	if err != nil {
		return nil, decodeError(err)
	}

	return &InstanceConfig{
		Count:            1,
		Hostname:         utils.RandomName(),
		ReverseDNS:       "",
		Size:             "g3.medium",
		Region:           c.Region,
		PublicIPRequired: "true",
		NetworkID:        network.ID,
		TemplateID:       diskimage.ID,
		SnapshotID:       "",
		InitialUser:      "civo",
		SSHKeyID:         "",
		Script:           "",
		Tags:             []string{""},
		FirewallID:       "",
	}, nil
}

// CreateInstance creates a new instance in the account
func (c *Client) CreateInstance(config *InstanceConfig) (*Instance, error) {
	config.TagsList = strings.Join(config.Tags, " ")
	body, err := c.SendPostRequest("/v2/instances", config)
	if err != nil {
		return nil, decodeError(err)
	}

	var instance Instance
	if err := json.NewDecoder(bytes.NewReader(body)).Decode(&instance); err != nil {
		return nil, err
	}

	return &instance, nil
}

// SetInstanceTags sets the tags for the specified instance
func (c *Client) SetInstanceTags(i *Instance, tags string) (*SimpleResponse, error) {
	resp, err := c.SendPutRequest(fmt.Sprintf("/v2/instances/%s/tags", i.ID), map[string]string{
		"tags":   tags,
		"region": c.Region,
	})
	if err != nil {
		return nil, decodeError(err)
	}

	response, err := c.DecodeSimpleResponse(resp)
	return response, err
}

// UpdateInstance updates an Instance's hostname, reverse DNS or notes
func (c *Client) UpdateInstance(i *Instance) (*SimpleResponse, error) {
	params := map[string]string{
		"hostname":    i.Hostname,
		"reverse_dns": i.ReverseDNS,
		"notes":       i.Notes,
		"region":      c.Region,
	}

	if i.Notes == "" {
		params["notes_delete"] = "true"
	}

	resp, err := c.SendPutRequest(fmt.Sprintf("/v2/instances/%s", i.ID), params)
	if err != nil {
		return nil, decodeError(err)
	}

	response, err := c.DecodeSimpleResponse(resp)
	return response, err
}

// DeleteInstance deletes an instance and frees its resources
func (c *Client) DeleteInstance(id string) (*SimpleResponse, error) {
	resp, err := c.SendDeleteRequest("/v2/instances/" + id)
	if err != nil {
		return nil, decodeError(err)
	}

	response, err := c.DecodeSimpleResponse(resp)
	return response, err
}

// RebootInstance reboots an instance (short version of HardRebootInstance)
func (c *Client) RebootInstance(id string) (*SimpleResponse, error) {
	return c.HardRebootInstance(id)
}

// HardRebootInstance harshly reboots an instance (like shutting the power off and booting it again)
func (c *Client) HardRebootInstance(id string) (*SimpleResponse, error) {
	resp, err := c.SendPostRequest(fmt.Sprintf("/v2/instances/%s/hard_reboots", id), map[string]string{
		"region": c.Region,
	})
	if err != nil {
		return nil, decodeError(err)
	}

	response, err := c.DecodeSimpleResponse(resp)
	return response, err
}

// SoftRebootInstance requests the VM to shut down nicely
func (c *Client) SoftRebootInstance(id string) (*SimpleResponse, error) {
	resp, err := c.SendPostRequest(fmt.Sprintf("/v2/instances/%s/soft_reboots", id), map[string]string{
		"region": c.Region,
	})
	if err != nil {
		return nil, decodeError(err)
	}

	response, err := c.DecodeSimpleResponse(resp)
	return response, err
}

// StopInstance shuts the power down to the instance
func (c *Client) StopInstance(id string) (*SimpleResponse, error) {
	resp, err := c.SendPutRequest(fmt.Sprintf("/v2/instances/%s/stop", id), map[string]string{
		"region": c.Region,
	})
	if err != nil {
		return nil, decodeError(err)
	}

	response, err := c.DecodeSimpleResponse(resp)
	return response, err
}

// StartInstance starts the instance booting from the shutdown state
func (c *Client) StartInstance(id string) (*SimpleResponse, error) {
	resp, err := c.SendPutRequest(fmt.Sprintf("/v2/instances/%s/start", id), map[string]string{
		"region": c.Region,
	})
	if err != nil {
		return nil, decodeError(err)
	}

	response, err := c.DecodeSimpleResponse(resp)
	return response, err
}

// GetInstanceConsoleURL gets the web URL for an instance's console
func (c *Client) GetInstanceConsoleURL(id string) (string, error) {
	resp, err := c.SendGetRequest(fmt.Sprintf("/v2/instances/%s/console", id))
	if err != nil {
		return "", decodeError(err)
	}

	console := InstanceConsole{}
	err = json.NewDecoder(bytes.NewReader(resp)).Decode(&console)
	return console.URL, err
}

// UpgradeInstance resizes the instance up to the new specification
// it's not possible to resize the instance to a smaller size
func (c *Client) UpgradeInstance(id, newSize string) (*SimpleResponse, error) {
	resp, err := c.SendPutRequest(fmt.Sprintf("/v2/instances/%s/resize", id), map[string]string{
		"size":   newSize,
		"region": c.Region,
	})
	if err != nil {
		return nil, decodeError(err)
	}

	response, err := c.DecodeSimpleResponse(resp)
	return response, err
}

// MovePublicIPToInstance moves a public IP to the specified instance
func (c *Client) MovePublicIPToInstance(id, ipAddress string) (*SimpleResponse, error) {
	resp, err := c.SendPutRequest(fmt.Sprintf("/v2/instances/%s/ip/%s", id, ipAddress), "")
	if err != nil {
		return nil, decodeError(err)
	}

	response, err := c.DecodeSimpleResponse(resp)
	return response, err
}

// SetInstanceFirewall changes the current firewall for an instance
func (c *Client) SetInstanceFirewall(id, firewallID string) (*SimpleResponse, error) {
	resp, err := c.SendPutRequest(fmt.Sprintf("/v2/instances/%s/firewall", id), map[string]string{
		"firewall_id": firewallID,
		"region":      c.Region,
	})
	if err != nil {
		return nil, decodeError(err)
	}

	response, err := c.DecodeSimpleResponse(resp)
	return response, err
}