package main

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

type gtsClient struct {
	authentication Authentication
	httpClient     http.Client
	userAgent      string
	timeout        time.Duration
}

func newGtsClient(authentication Authentication) *gtsClient {
	httpClient := http.Client{}

	client := gtsClient{
		authentication: authentication,
		httpClient:     httpClient,
		userAgent:      userAgent,
		timeout:        5 * time.Second,
	}

	return &client
}

func (g *gtsClient) verifyCredentials() (Account, error) {
	path := "/api/v1/accounts/verify_credentials"
	url := g.authentication.Instance + path

	ctx, cancel := context.WithTimeout(context.Background(), g.timeout)
	defer cancel()

	request, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
	if err != nil {
		return Account{}, fmt.Errorf("unable to create the HTTP request; %w", err)
	}

	var account Account

	if err := g.sendRequest(request, &account); err != nil {
		return Account{}, fmt.Errorf("received an error after sending the request to verify the credentials; %w", err)
	}

	return account, nil
}

func (g *gtsClient) sendRequest(request *http.Request, object any) error {
	request.Header.Set("Content-Type", "application/json; charset=utf-8")
	request.Header.Set("Accept", "application/json; charset=utf-8")
	request.Header.Set("User-Agent", g.userAgent)

	if len(g.authentication.AccessToken) > 0 {
		request.Header.Set("Authorization", fmt.Sprintf("Bearer %s", g.authentication.AccessToken))
	}

	response, err := g.httpClient.Do(request)
	if err != nil {
		return fmt.Errorf("received an error after sending the request; %w", err)
	}

	defer response.Body.Close()

	if response.StatusCode < http.StatusOK || response.StatusCode >= http.StatusBadRequest {
		return fmt.Errorf(
			"did not receive an OK response from the GoToSocial server; got %d",
			response.StatusCode,
		)
	}

	if err := json.NewDecoder(response.Body).Decode(object); err != nil {
		return fmt.Errorf(
			"unable to decode the response from the GoToSocial server; %w",
			err,
		)
	}

	return nil
}