// Package pluralkit is a binding to the PluralKit API as documented here: https://pluralkit.me/api
package pluralkit

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

	"within.website/x/web"
)

// Client connects to the PluralKit API.
type Client struct {
	baseURL string
	token   string
	hc      *http.Client
}

// RoundTrip sends an authenticated request to the PluralKit API.
func (c Client) RoundTrip(req *http.Request) (*http.Response, error) {
	req.Header.Set("Authorization", c.token)
	return c.hc.Do(req)
}

// Do is a high level wrapper for sending data to/from the PluralKit API.
func (c Client) Do(method, pathNoSlash string, want int, post interface{}, result interface{}) error {
	var body io.Reader
	if post != nil {
		var buf bytes.Buffer
		err := json.NewEncoder(&buf).Encode(post)
		if err != nil {
			return nil
		}
		body = &buf
	}
	req := c.MakeRequest(method, pathNoSlash, body)
	if post != nil {
		req.Header.Set("Content-Type", "application/json")
	}
	resp, err := c.RoundTrip(req)
	if err != nil {
		return err
	}

	if resp.StatusCode != want {
		return web.NewError(want, resp)
	}

	defer resp.Body.Close()

	err = json.NewDecoder(resp.Body).Decode(result)
	if err != nil {
		return err
	}

	return nil
}

// MakeRequest makes a HTTP request for the PluralKit API, catting pathNoSlash to the base PluralKit API address.
func (c Client) MakeRequest(method, pathNoSlash string, body io.Reader) *http.Request {
	req, err := http.NewRequest(method, c.baseURL+pathNoSlash, body)
	if err != nil /* programmer error */ {
		panic(err)
	}

	return req
}

// New creates a new instance of the PluralKit API client.
func New(token string, hc *http.Client) Client {
	return Client{
		baseURL: "https://api.pluralkit.me/v1/",
		token:   token,
		hc:      hc,
	}
}