package server

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

// ChallengeTestSrvDNS talks to pebble-challtestsrv's management API, for
// development against a local Pebble ACME server (DNS_PROVIDER=challtestsrv).
type ChallengeTestSrvDNS struct {
	BaseURL string // default http://127.0.0.1:8055
	HTTP    *http.Client
}

func (c *ChallengeTestSrvDNS) base() string {
	if c.BaseURL != "" {
		return c.BaseURL
	}
	return "http://127.0.0.1:8055"
}

func (c *ChallengeTestSrvDNS) client() *http.Client {
	if c.HTTP != nil {
		return c.HTTP
	}
	return &http.Client{Timeout: 10 * time.Second}
}

func (c *ChallengeTestSrvDNS) post(ctx context.Context, path string, body map[string]string) error {
	raw, err := json.Marshal(body)
	if err != nil {
		return err
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.base()+path, bytes.NewReader(raw))
	if err != nil {
		return err
	}
	req.Header.Set("Content-Type", "application/json")
	resp, err := c.client().Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		data, _ := io.ReadAll(io.LimitReader(resp.Body, 512))
		return fmt.Errorf("challtestsrv %s: HTTP %d: %s", path, resp.StatusCode, data)
	}
	return nil
}

func (c *ChallengeTestSrvDNS) CreateTXT(ctx context.Context, name, value string) error {
	return c.post(ctx, "/set-txt", map[string]string{"host": name, "value": value})
}

func (c *ChallengeTestSrvDNS) DeleteTXT(ctx context.Context, name string) error {
	return c.post(ctx, "/clear-txt", map[string]string{"host": name})
}