// Provider communication — mDNS discovery, device registration, screen fetch.

#include "provider.hpp"

#include <cstdio>
#include <cstring>

#include "esp_log.h"
#include "mdns.h"
#include "sdkconfig.h"

#include "http_client.hpp"
#include "network.hpp"

static const char *TAG = "Provider";

// ── mDNS Provider Discovery ────────────────────────────────────────────────

// Resolve the Provider's IP via mDNS. Returns true and fills `out_ip` on
// success. Falls back to CONFIG_CALENDINK_PROVIDER_FALLBACK_IP if set.
static bool resolve_provider_ip(char *out_ip, size_t out_ip_len)
{
  ESP_LOGI(TAG, "Resolving Provider via mDNS: %s.local",
           CONFIG_CALENDINK_PROVIDER_MDNS_HOSTNAME);

  esp_err_t err = mdns_init();
  if (err != ESP_OK)
  {
    ESP_LOGE(TAG, "mDNS init failed: %s", esp_err_to_name(err));
    goto fallback;
  }

  {
    esp_ip4_addr_t addr = {};
    constexpr int kMaxRetries = 3;
    for (int attempt = 1; attempt <= kMaxRetries; attempt++)
    {
      err = mdns_query_a(CONFIG_CALENDINK_PROVIDER_MDNS_HOSTNAME, 5000, &addr);
      if (err == ESP_OK)
      {
        snprintf(out_ip, out_ip_len, IPSTR, IP2STR(&addr));
        ESP_LOGI(TAG, "Provider resolved: %s (attempt %d)", out_ip, attempt);
        return true;
      }
      ESP_LOGW(TAG, "mDNS attempt %d/%d failed: %s", attempt, kMaxRetries,
               esp_err_to_name(err));
    }
  }

fallback:
  if (strlen(CONFIG_CALENDINK_PROVIDER_FALLBACK_IP) > 0)
  {
    strlcpy(out_ip, CONFIG_CALENDINK_PROVIDER_FALLBACK_IP, out_ip_len);
    ESP_LOGW(TAG, "Using fallback IP: %s", out_ip);
    return true;
  }

  ESP_LOGE(TAG, "No fallback IP configured. Cannot reach Provider.");
  return false;
}

// ── Provider Communication Test ─────────────────────────────────────────────

bool test_provider_communication(uint8 *out_buffer, size_t buffer_size)
{
  bool success = false;

  // 1. Resolve Provider IP
  char provider_ip[16] = {};
  if (!resolve_provider_ip(provider_ip, sizeof(provider_ip)))
  {
    return false;
  }

  uint16_t provider_port = CONFIG_CALENDINK_PROVIDER_PORT;

  // 2. Get our own MAC address
  uint8_t mac_bytes[6] = {};
  esp_err_t err = get_mac_address(mac_bytes);
  if (err != ESP_OK)
  {
    ESP_LOGE(TAG, "Failed to get WiFi MAC: %s", esp_err_to_name(err));
    return false;
  }

  char mac_str[18] = {};
  snprintf(mac_str, sizeof(mac_str), "%02X:%02X:%02X:%02X:%02X:%02X",
           mac_bytes[0], mac_bytes[1], mac_bytes[2], mac_bytes[3], mac_bytes[4],
           mac_bytes[5]);
  ESP_LOGI(TAG, "Client MAC: %s", mac_str);

  // 3. Register with Provider: POST /api/devices/register
  //    This may return "already_registered" — that's fine, we continue regardless.
  {
    char *url =
        http_build_url(provider_ip, provider_port, "/api/devices/register");
    if (url != nullptr)
    {
      char json_body[64] = {};
      snprintf(json_body, sizeof(json_body), "{\"mac\":\"%s\"}", mac_str);

      http_text_response_t resp = {};
      err = http_post_json(url, json_body, &resp);

      if (err == ESP_OK)
      {
        ESP_LOGI(TAG, "Register response (%d): %s", resp.status_code,
                 resp.body ? resp.body : "(empty)");
      }
      else
      {
        ESP_LOGW(TAG, "Register request failed: %s (continuing anyway)",
                 esp_err_to_name(err));
      }

      free(resp.body);
      free(url);
    }
  }

  // 4. Fetch screen bitmap: GET /api/devices/screen.bin?mac=XX:XX:XX:XX:XX:XX
  {
    char path[80] = {};
    snprintf(path, sizeof(path), "/api/devices/screen.bin?mac=%s", mac_str);

    char *url = http_build_url(provider_ip, provider_port, path);
    if (url == nullptr)
    {
      return false;
    }

    http_binary_response_t resp = {};
    err = http_get_binary(url, &resp);

    if (err == ESP_OK && resp.status_code == 200)
    {
      ESP_LOGI(TAG, "Screen bitmap response: %zu bytes", resp.data_len);
      if (resp.data != nullptr && resp.data_len > 0)
      {
        size_t copy_size = (resp.data_len < buffer_size) ? resp.data_len : buffer_size;
        memcpy(out_buffer, resp.data, copy_size);
        success = true;

        // Debug: log first 10 bytes (should be 0xFF for white top-left pixels)
        ESP_LOGI(TAG, "First 10 bytes: %02X %02X %02X %02X %02X %02X %02X %02X %02X %02X",
                 out_buffer[0], out_buffer[1], out_buffer[2], out_buffer[3],
                 out_buffer[4], out_buffer[5], out_buffer[6], out_buffer[7],
                 out_buffer[8], out_buffer[9]);
      }
    }
    else
    {
      ESP_LOGE(TAG, "Screen bitmap request failed: %s (status %d)",
               esp_err_to_name(err), resp.status_code);
    }

    free(resp.data);
    free(url);
  }

  return success;
}