package emgql

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"time"

	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
	"go.uber.org/zap"

	"go.equinixmetal.net/infra9-metal-bridge/internal/metal/providers"
)

const (
	defaultHTTPTimeout = 5 * time.Second
)

// DefaultHTTPClient is the default http client used if no client is provided.
var DefaultHTTPClient = &http.Client{
	Timeout:   defaultHTTPTimeout,
	Transport: otelhttp.NewTransport(http.DefaultTransport),
}

var _ providers.Provider = &Client{}

// Client is the client to interact with the equinix metal graphql service.
type Client struct {
	logger     *zap.SugaredLogger
	httpClient *http.Client
	baseURL    *url.URL
}

// New creates a new emapi client
func New(options ...Option) (*Client, error) {
	client := &Client{}

	for _, opt := range options {
		if err := opt(client); err != nil {
			return nil, err
		}
	}

	if client.logger == nil {
		client.logger = zap.NewNop().Sugar()
	}

	if client.httpClient == nil {
		client.httpClient = DefaultHTTPClient
	}

	return client, nil
}

func (c *Client) graphquery(ctx context.Context, q string, vars map[string]string) (io.ReadCloser, error) {
	qObj := struct {
		Query     string            `json:"query"`
		Variables map[string]string `json:"variables"`
	}{
		Query:     q,
		Variables: vars,
	}

	res, err := json.Marshal(qObj)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal request object: %w", err)
	}

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.baseURL.String(), bytes.NewBuffer(res))
	if err != nil {
		return nil, fmt.Errorf("failed to build post request: %w", err)
	}

	req.Header.Add("content-type", "application/json")

	resp, err := c.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to make post request: %w", err)
	}

	if resp.StatusCode != http.StatusOK {
		b, err2 := io.ReadAll(resp.Body)
		if err2 != nil {
			return nil, fmt.Errorf("got unexpected response code [%d]: unable to parse request body: %v", resp.StatusCode, err)
		}

		return nil, fmt.Errorf("got unexpected response code [%d]: %s", resp.StatusCode, string(b))
	}
	return resp.Body, nil

}