// Copyright (C) 2020 Marius Schellenberger

package pve

import (
	"context"
	"errors"
	"fmt"
	"net/http"
)

var (
	ErrPoolExists    = errors.New("pool already exists")
	ErrPoolNotExists = errors.New("pool does not exist")
	ErrEmptyPoolName = errors.New("pool name is empty")
)

func MakePoolName(namespace, name string) string {
	return fmt.Sprintf("%s-%s", namespace, name)
}

type PoolClient struct {
	client *Client
}

func (c *PoolClient) exists(ctx context.Context, name string) (status int, err error) {
	req, err := c.client.NewRequest(ctx, "GET", fmt.Sprintf("/pools/%s", name), nil)
	if err != nil {
		return
	}
	resp, err := c.client.Do(req, nil)
	if err != nil {
		if !errors.Is(err, HTTPErr) {
			return
		}
		err = nil
	}
	status = resp.StatusCode
	return
}

func (c *PoolClient) Create(ctx context.Context, name string) (err error) {
	status, err := c.exists(ctx, name)
	if err != nil {
		return
	}
	if status == http.StatusOK {
		return ErrPoolExists
	}

	body := httpbody{"poolid": name}
	req, err := c.client.NewRequest(ctx, "POST", "/pools", body.Reader())
	if err != nil {
		return
	}
	_, err = c.client.Do(req, nil)
	return
}

func (c *PoolClient) Delete(ctx context.Context, name string) (err error) {
	status, err := c.exists(ctx, name)
	if err != nil {
		return
	}
	if status != http.StatusOK {
		return ErrPoolNotExists
	}

	req, err := c.client.NewRequest(ctx, "DELETE", fmt.Sprintf("/pools/%s", name), nil)
	if err != nil {
		return
	}
	_, err = c.client.Do(req, nil)
	return
}

type pools struct {
	PoolID string `json:"poolid"`
}

func (c *PoolClient) ListPools(ctx context.Context) (list []string, err error) {
	var ps []pools
	req, err := c.client.NewRequest(ctx, "GET", "/pools", nil)
	if err != nil {
		return
	}
	_, err = c.client.Do(req, &ps)
	if err != nil {
		return
	}
	for _, p := range ps {
		list = append(list, p.PoolID)
	}
	return
}

type poolMember struct {
	ID   int    `json:"vmid"`
	Name string `json:"name"`
	Node string `json:"node"`
}

type poolMembers []poolMember

func (pms poolMembers) ServerList() (sl ServerRefList) {
	for _, pm := range pms {
		sl = append(sl, &ServerRef{
			ID:   pm.ID,
			Name: pm.Name,
			Node: pm.Node,
		})
	}
	return
}

type pool struct {
	Members poolMembers `json:"members"`
}

func (c *PoolClient) ListMembers(ctx context.Context, name string) (sl ServerRefList, err error) {
	if name == "" {
		err = ErrEmptyPoolName
		return
	}
	var p pool
	req, err := c.client.NewRequest(ctx, "GET", fmt.Sprintf("/pools/%s", name), nil)
	if err != nil {
		return
	}
	_, err = c.client.Do(req, &p)
	sl = p.Members.ServerList()
	return
}

func (c *PoolClient) FindServer(ctx context.Context, poolname, servername string, id int) (s *ServerRef, err error) {
	var pools []string
	if poolname != "" {
		pools = append(pools, poolname)
	} else {
		pools, err = c.ListPools(ctx)
		if err != nil {
			return
		}
	}
	for _, pool := range pools {
		sl, err := c.ListMembers(ctx, pool)
		if err != nil {
			return nil, err
		}
		for _, srv := range sl {
			if id != -1 && srv.ID == id {
				srv.Pool = pool
				return srv, nil
			}
			if servername != "" && srv.Name == servername {
				srv.Pool = pool
				return srv, nil
			}
		}
	}
	return nil, ErrServerNotFound
}

func (c *PoolClient) FindServerByName(ctx context.Context, poolname, servername string) (s *ServerRef, err error) {
	return c.FindServer(ctx, poolname, servername, -1)
}

func (c *PoolClient) FindServerByID(ctx context.Context, poolname string, id int) (s *ServerRef, err error) {
	return c.FindServer(ctx, poolname, "", id)
}

func (c *PoolClient) FindServerByURL(ctx context.Context, url string) (s *ServerRef, err error) {
	pool, _, id, err := ParseURL(url)
	if err != nil {
		return
	}
	return c.FindServerByID(ctx, pool, id)
}