package csi

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"k8s.io/klog"
	"net/http"
	"strings"
)

type p5xApi struct {
	endpoint string
	port     int64
	token    string
}

type p5xVolume struct {
	VolumeId    int64  `json:"volumeId"`
	Name        string `json:"name"`
	SizeInBytes int64  `json:"sizeInBytes"`
}

func (p5x *p5xApi) CreateVolume(name string, sizeInBytes int64) (*p5xVolume, error) {
	vol := &p5xVolume{
		VolumeId:    0,
		Name:        name,
		SizeInBytes: sizeInBytes,
	}
	klog.Info("p5x.CreateVolume: Attempting to create: ", vol)

	body, err := json.Marshal(vol)
	if err != nil {
		return nil, err
	}

	resBody, err := p5x.MakeRequest(http.MethodPost, "volumes", body)
	if err != nil {
		return nil, err
	}

	err = json.Unmarshal(resBody, vol)
	klog.Info("p5x.CreateVolume: Successfully created volume: ", vol)

	return vol, nil
}

var ErrVolumeNotFound = errors.New("p5x volume not found")

func (p5x *p5xApi) GetVolumeByName(name string) (*p5xVolume, error) {
	klog.Infof("p5x.GetVolumeByName: %s", name)
	route := fmt.Sprintf("volumes/%s", name)
	resBody, err := p5x.MakeRequest(http.MethodGet, route, nil)
	if err != nil {
		return nil, err
	}

	if strings.Contains(string(resBody[:]), "Could not find volume with the name") {
		return nil, ErrVolumeNotFound
	}

	vol := &p5xVolume{}
	err = json.Unmarshal(resBody, vol)
	if err != nil {
		return nil, err
	}

	klog.Info("p5x.GetVolumeByName: Retrieved volume: ", vol)
	return vol, nil
}

func (p5x *p5xApi) DeleteVolume(volume *p5xVolume) error {
	klog.Info("p5x.DeleteVolume: ", volume)
	route := fmt.Sprintf("volumes/%s", volume.Name)
	resBody, err := p5x.MakeRequest(http.MethodDelete, route, []byte(`{}`))
	if err != nil {
		return err
	}

	klog.Infof("p5x.DeleteVolume: Successfully deleted volume %s: %s", volume.Name, resBody)
	return nil
}

func (p5x *p5xApi) TransferVolume(volume *p5xVolume, nodeName string) (*p5xVolume, error) {
	klog.Info("p5x.TransferVolume: ", volume, " | to node: ", nodeName)
	route := fmt.Sprintf("volumes/%s/transfer-to/%s", volume.Name, nodeName)
	resBody, err := p5x.MakeRequest(http.MethodPost, route, []byte(`{}`))
	if err != nil {
		return nil, err
	}

	vol := &p5xVolume{}
	err = json.Unmarshal(resBody, vol)
	if err != nil {
		return nil, err
	}

	klog.Info("p5x.TransferVolume: Successfully transferred volume:", volume.Name, vol)
	return vol, nil
}

type MountVolumeRequest struct {
	Mountpoint string            `json:"mountpoint"`
	Options    map[string]string `json:"options"`
}

func (p5x *p5xApi) MountVolume(volume *p5xVolume, mountpoint string, options map[string]string) (*p5xVolume, error) {
	klog.Info("p5x.MountVolume: ", volume, mountpoint, options)
	req := &MountVolumeRequest{
		Mountpoint: mountpoint,
		Options:    options,
	}

	body, err := json.Marshal(req)
	if err != nil {
		return nil, err
	}

	route := fmt.Sprintf("volumes/%s/mount", volume.Name)
	resBody, err := p5x.MakeRequest(http.MethodPost, route, body)
	if err != nil {
		return nil, err
	}

	vol := &p5xVolume{}
	err = json.Unmarshal(resBody, vol)
	if err != nil {
		return nil, err
	}

	klog.Info("p5x.MountVolume: Successfully mounted volume: ", volume.Name, mountpoint)
	return vol, nil
}

func (p5x *p5xApi) UnmountVolume(volume *p5xVolume) (*p5xVolume, error) {
	klog.Info("p5x.UnmountVolume: ", volume)

	route := fmt.Sprintf("volumes/%s/unmount", volume.Name)
	resBody, err := p5x.MakeRequest(http.MethodPost, route, []byte(`{}`))
	if err != nil {
		return nil, err
	}

	vol := &p5xVolume{}
	err = json.Unmarshal(resBody, vol)
	if err != nil {
		return nil, err
	}

	klog.Info("p5x.UnmountVolume: Successfully unmounted volume: ", volume.Name)
	return vol, nil
}

func (p5x *p5xApi) MakeRequest(method string, route string, body []byte) ([]byte, error) {
	url := fmt.Sprintf("%s:%d/api/v1/%s", p5x.endpoint, p5x.port, route)
	klog.Infof("p5x.MakeRequest: [%s] %s", method, url)

	var res *http.Response
	var err error
	if method == http.MethodGet {
		res, err = http.Get(url)
		if err != nil {
			return nil, err
		}
	} else {
		klog.Infof("p5x.MakeRequest: body: %s", body)
		bodyReader := bytes.NewReader(body)
		req, err2 := http.NewRequest(method, url, bodyReader)
		if err2 != nil {
			klog.Errorf("p5x.MakeRequest: could not create request: %s\n", err)
			return nil, err2
		}

		req.Header.Set("Accept", "application/json")
		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", p5x.token))
		req.Header.Set("Content-Type", "application/json")
		res, err = http.DefaultClient.Do(req)
	}

	if err != nil {
		klog.Errorf("p5x.MakeRequest: error executing request: %s\n", err)
		return nil, err
	}

	resBody, err := io.ReadAll(res.Body)
	if err != nil {
		klog.Errorf("p5x.MakeRequest: could not read response body: %s\n", err)
		return nil, err
	}
	klog.Infof("p5x.MakeRequest: response body: %s\n", resBody)
	return resBody, nil
}