#include "aes67_web.h"

#include "esp_log.h"
#include "esp_system.h"
#include "esp_timer.h"

#define MAX_STATUS_CBS  16
#define MAX_URIS        32
#define MAX_EARLY_URIS  16

static const char *TAG = "web";

extern const char index_html_start[] asm("_binary_index_html_start");
extern const char index_html_end[] asm("_binary_index_html_end");

static httpd_handle_t s_httpd;
static status_cb_t s_status_cbs[MAX_STATUS_CBS];
static int s_status_n;
static httpd_uri_t s_early_uris[MAX_EARLY_URIS];
static int s_early_n;

esp_err_t status_register(status_cb_t cb)
{
    if (s_status_n >= MAX_STATUS_CBS) {
        return ESP_ERR_NO_MEM;
    }
    s_status_cbs[s_status_n++] = cb;
    return ESP_OK;
}

esp_err_t web_register_uri(const httpd_uri_t *uri)
{
    if (s_httpd) {
        return httpd_register_uri_handler(s_httpd, uri);
    }
    if (s_early_n >= MAX_EARLY_URIS) {
        return ESP_ERR_NO_MEM;
    }
    s_early_uris[s_early_n++] = *uri;
    return ESP_OK;
}

esp_err_t web_send_json(httpd_req_t *req, const cJSON *json)
{
    char *body = cJSON_PrintUnformatted(json);
    if (!body) {
        return httpd_resp_send_err(req, HTTPD_500_INTERNAL_SERVER_ERROR, "out of memory");
    }
    httpd_resp_set_type(req, "application/json");
    httpd_resp_set_hdr(req, "Cache-Control", "no-store");
    esp_err_t err = httpd_resp_sendstr(req, body);
    cJSON_free(body);
    return err;
}

static esp_err_t index_get(httpd_req_t *req)
{
    httpd_resp_set_type(req, "text/html; charset=utf-8");
    // EMBED_TXTFILES appends a NUL; don't send it.
    return httpd_resp_send(req, index_html_start, index_html_end - index_html_start - 1);
}

static esp_err_t status_get(httpd_req_t *req)
{
    cJSON *st = cJSON_CreateObject();
    for (int i = 0; i < s_status_n; i++) {
        s_status_cbs[i](st);
    }
    esp_err_t err = web_send_json(req, st);
    cJSON_Delete(st);
    return err;
}

static void reboot_cb(void *arg)
{
    esp_restart();
}

static esp_err_t reboot_post(httpd_req_t *req)
{
    ESP_LOGW(TAG, "reboot requested via API");
    httpd_resp_sendstr(req, "");
    // Let the response go out before restarting.
    const esp_timer_create_args_t args = { .callback = reboot_cb, .name = "reboot" };
    esp_timer_handle_t t;
    if (esp_timer_create(&args, &t) == ESP_OK) {
        esp_timer_start_once(t, 500 * 1000);
    }
    return ESP_OK;
}

esp_err_t aes67_web_start(void)
{
    httpd_config_t cfg = HTTPD_DEFAULT_CONFIG();
    cfg.max_uri_handlers = MAX_URIS;
    cfg.stack_size = 8192;
    cfg.lru_purge_enable = true;
    cfg.uri_match_fn = httpd_uri_match_wildcard;

    esp_err_t err = httpd_start(&s_httpd, &cfg);
    if (err != ESP_OK) {
        ESP_LOGE(TAG, "httpd start failed: %s", esp_err_to_name(err));
        return err;
    }

    static const httpd_uri_t core[] = {
        { .uri = "/",           .method = HTTP_GET,  .handler = index_get },
        { .uri = "/index.html", .method = HTTP_GET,  .handler = index_get },
        { .uri = "/api/status", .method = HTTP_GET,  .handler = status_get },
        { .uri = "/api/reboot", .method = HTTP_POST, .handler = reboot_post },
    };
    for (int i = 0; i < sizeof(core) / sizeof(core[0]); i++) {
        httpd_register_uri_handler(s_httpd, &core[i]);
    }
    for (int i = 0; i < s_early_n; i++) {
        httpd_register_uri_handler(s_httpd, &s_early_uris[i]);
    }

    ESP_LOGI(TAG, "httpd started, index.html %d bytes, %d project routes",
             (int)(index_html_end - index_html_start - 1), s_early_n);
    return ESP_OK;
}