#include "rest_server_internal.h"

#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include "esp_heap_caps.h"
#include "mbedtls/base64.h"
#include "domain.h"

#define REST_SERVER_MAX_BODY_BYTES (4 * 1024 * 1024)

static void *alloc_prefer_psram(size_t size) {
    void *ptr = heap_caps_malloc(size, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
    if (ptr == NULL) {
        ptr = malloc(size);
    }
    return ptr;
}

static void *calloc_prefer_psram(size_t n, size_t size) {
    void *ptr = heap_caps_calloc(n, size, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
    if (ptr == NULL) {
        ptr = calloc(n, size);
    }
    return ptr;
}
bool rest_server_auth_ok(httpd_req_t *req) {
    if (strlen(CONFIG_TQ_API_KEY) == 0) {
        return true;
    }

    char buf[96] = {0};
    if (httpd_req_get_hdr_value_str(req, "X-API-Key", buf, sizeof(buf)) != ESP_OK) {
        return false;
    }

    return strcmp(buf, CONFIG_TQ_API_KEY) == 0;
}

esp_err_t rest_server_send_json(httpd_req_t *req, const char *status, cJSON *root) {
    char *text = cJSON_PrintUnformatted(root);
    if (text == NULL) {
        return httpd_resp_send_err(req, HTTPD_500_INTERNAL_SERVER_ERROR, "json encode failed");
    }

    httpd_resp_set_type(req, "application/json");
    httpd_resp_set_status(req, status);
    esp_err_t err = httpd_resp_sendstr(req, text);
    cJSON_free(text);
    domain_diag_counter_add(DOMAIN_DIAG_COUNTER_REST_RESPONSES_TOTAL, 1);
    return err;
}

esp_err_t rest_server_send_error(httpd_req_t *req, const char *status, const char *message) {
    cJSON *root = cJSON_CreateObject();
    cJSON_AddBoolToObject(root, "ok", false);
    cJSON_AddStringToObject(root, "error", message != NULL ? message : "unknown");
    esp_err_t err = rest_server_send_json(req, status, root);
    cJSON_Delete(root);
    domain_diag_counter_add(DOMAIN_DIAG_COUNTER_REST_ERRORS_TOTAL, 1);
    domain_diag_record_error("rest_api", ESP_FAIL, message != NULL ? message : "unknown");
    return err;
}

esp_err_t rest_server_read_body(httpd_req_t *req, char **out_body) {
    if (out_body == NULL) {
        return ESP_ERR_INVALID_ARG;
    }

    *out_body = NULL;

    if (req->content_len <= 0 || req->content_len > REST_SERVER_MAX_BODY_BYTES) {
        return ESP_ERR_INVALID_SIZE;
    }

    char *buf = (char *)calloc_prefer_psram(1, (size_t)req->content_len + 1);
    if (buf == NULL) {
        return ESP_ERR_NO_MEM;
    }

    int received = 0;
    while (received < req->content_len) {
        int ret = httpd_req_recv(req, buf + received, req->content_len - received);
        if (ret <= 0) {
            free(buf);
            return ESP_FAIL;
        }
        received += ret;
    }

    *out_body = buf;
    return ESP_OK;
}

bool rest_server_parse_uri_u32_tail(const char *uri, uint32_t *out_value) {
    if (uri == NULL || out_value == NULL) {
        return false;
    }

    const char *slash = strrchr(uri, '/');
    if (slash == NULL || *(slash + 1) == '\0') {
        return false;
    }

    errno = 0;
    char *endptr = NULL;
    unsigned long val = strtoul(slash + 1, &endptr, 10);
    if (errno != 0 || endptr == slash + 1 || *endptr != '\0' || val > UINT32_MAX) {
        return false;
    }

    *out_value = (uint32_t)val;
    return true;
}

esp_err_t rest_server_base64_decode_alloc(const char *b64, uint8_t **out_raw, size_t *out_len) {
    if (b64 == NULL || out_raw == NULL || out_len == NULL) {
        return ESP_ERR_INVALID_ARG;
    }

    *out_raw = NULL;
    *out_len = 0;

    size_t decoded_len = 0;
    int rc = mbedtls_base64_decode(NULL,
                                   0,
                                   &decoded_len,
                                   (const unsigned char *)b64,
                                   strlen(b64));
    if (!(rc == 0 || rc == MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL)) {
        return ESP_ERR_INVALID_ARG;
    }

    uint8_t *buf = (uint8_t *)alloc_prefer_psram(decoded_len);
    if (buf == NULL) {
        return ESP_ERR_NO_MEM;
    }

    rc = mbedtls_base64_decode(buf,
                               decoded_len,
                               &decoded_len,
                               (const unsigned char *)b64,
                               strlen(b64));
    if (rc != 0) {
        free(buf);
        return ESP_ERR_INVALID_ARG;
    }

    *out_raw = buf;
    *out_len = decoded_len;
    return ESP_OK;
}

bool rest_server_json_bool_with_default(cJSON *item, bool default_value) {
    if (item == NULL) {
        return default_value;
    }
    if (cJSON_IsBool(item)) {
        return cJSON_IsTrue(item);
    }
    return default_value;
}