package client

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
	"net/url"
	"strings"

	"git.ctrlz.es/mgdelacroix/birthdaybot/model"
)

var (
	ErrEmptyURL = errors.New("URL cannot be empty")
)

type Client struct {
	url        string
	httpClient *http.Client
	headers    map[string]string
}

func New(opts ...Option) (*Client, error) {
	client := &Client{
		httpClient: &http.Client{},
	}

	for _, opt := range opts {
		client = opt(client)
	}

	if client.url == "" {
		return nil, ErrEmptyURL
	}

	return client, nil
}

func (c *Client) Do(ctx context.Context, method, path, data string, headers map[string]string) (*http.Response, error) {
	url, err := url.JoinPath(c.url, path)
	if err != nil {
		return nil, fmt.Errorf("cannot build request url: %w", err)
	}

	req, err := http.NewRequestWithContext(ctx, method, url, strings.NewReader(data))
	if err != nil {
		return nil, fmt.Errorf("cannot create request: %w", err)
	}

	for k, v := range c.headers {
		req.Header.Set(k, v)
	}

	for k, v := range headers {
		req.Header.Set(k, v)
	}

	resp, err := c.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("cannot do request: %w", err)
	}

	return resp, nil
}

func (c *Client) Health(ctx context.Context) (bool, error) {
	resp, err := c.Do(ctx, http.MethodGet, "/health", "", nil)
	if err != nil {
		return false, err
	}
	defer resp.Body.Close()

	return resp.StatusCode == 200, nil
}

func (c *Client) NextBirthdays(ctx context.Context) ([]*model.Birthday, error) {
	resp, err := c.Do(ctx, http.MethodGet, "/next_birthdays", "", nil)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	var birthdays []*model.Birthday
	if err := json.NewDecoder(resp.Body).Decode(&birthdays); err != nil {
		return nil, fmt.Errorf("cannot decode birthdays: %w", err)
	}

	return birthdays, nil
}