v0.4.8 - Implement web server functionality for embedded admin interface - serve HTML/CSS/JS from /api/ endpoint with proper MIME types, CORS headers, and performance optimizations

src/api.c

@@ -0,0 +1,165 @@
+// Define _GNU_SOURCE to ensure all POSIX features are available
+#define _GNU_SOURCE
+
+// API module for serving embedded web content
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <libwebsockets.h>
+#include "api.h"
+#include "embedded_web_content.h"
+
+// Forward declarations for logging functions
+void log_info(const char* message);
+void log_success(const char* message);
+void log_error(const char* message);
+void log_warning(const char* message);
+
+// Handle HTTP request for embedded files (assumes GET)
+int handle_embedded_file_request(struct lws* wsi, const char* requested_uri) {
+    log_info("Handling embedded file request");
+
+    const char* file_path;
+
+    // Handle /api requests
+    char temp_path[256];
+    if (strcmp(requested_uri, "/api") == 0) {
+        // /api -> serve index.html
+        file_path = "/";
+    } else if (strncmp(requested_uri, "/api/", 5) == 0) {
+        // Extract file path from /api/ prefix and add leading slash for lookup
+        snprintf(temp_path, sizeof(temp_path), "/%s", requested_uri + 5); // Add leading slash
+        file_path = temp_path;
+    } else {
+        log_warning("Embedded file request without /api prefix");
+        lws_return_http_status(wsi, HTTP_STATUS_NOT_FOUND, NULL);
+        return -1;
+    }
+
+    // Get embedded file
+    embedded_file_t* file = get_embedded_file(file_path);
+    if (!file) {
+        log_warning("Embedded file not found");
+        lws_return_http_status(wsi, HTTP_STATUS_NOT_FOUND, NULL);
+        return -1;
+    }
+
+    // Allocate session data
+    struct embedded_file_session_data* session_data = malloc(sizeof(struct embedded_file_session_data));
+    if (!session_data) {
+        log_error("Failed to allocate embedded file session data");
+        return -1;
+    }
+
+    session_data->type = 1; // Embedded file
+    session_data->data = file->data;
+    session_data->size = file->size;
+    session_data->content_type = file->content_type;
+    session_data->headers_sent = 0;
+    session_data->body_sent = 0;
+
+    // Store session data
+    lws_set_wsi_user(wsi, session_data);
+
+    // Prepare HTTP response headers
+    unsigned char buf[LWS_PRE + 1024];
+    unsigned char *p = &buf[LWS_PRE];
+    unsigned char *start = p;
+    unsigned char *end = &buf[sizeof(buf) - 1];
+
+    if (lws_add_http_header_status(wsi, HTTP_STATUS_OK, &p, end)) {
+        free(session_data);
+        return -1;
+    }
+
+    if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE, (unsigned char*)file->content_type, strlen(file->content_type), &p, end)) {
+        free(session_data);
+        return -1;
+    }
+
+    if (lws_add_http_header_content_length(wsi, file->size, &p, end)) {
+        free(session_data);
+        return -1;
+    }
+
+    // Add CORS headers (same as NIP-11 for consistency)
+    if (lws_add_http_header_by_name(wsi, (unsigned char*)"access-control-allow-origin:", (unsigned char*)"*", 1, &p, end)) {
+        free(session_data);
+        return -1;
+    }
+    if (lws_add_http_header_by_name(wsi, (unsigned char*)"access-control-allow-headers:", (unsigned char*)"content-type, accept", 20, &p, end)) {
+        free(session_data);
+        return -1;
+    }
+    if (lws_add_http_header_by_name(wsi, (unsigned char*)"access-control-allow-methods:", (unsigned char*)"GET, OPTIONS", 12, &p, end)) {
+        free(session_data);
+        return -1;
+    }
+
+    // Add Connection: close to ensure connection closes after response
+    if (lws_add_http_header_by_name(wsi, (unsigned char*)"connection:", (unsigned char*)"close", 5, &p, end)) {
+        free(session_data);
+        return -1;
+    }
+
+    if (lws_finalize_http_header(wsi, &p, end)) {
+        free(session_data);
+        return -1;
+    }
+
+    // Write headers
+    if (lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS) < 0) {
+        free(session_data);
+        return -1;
+    }
+
+    session_data->headers_sent = 1;
+
+    // Request callback for body transmission
+    lws_callback_on_writable(wsi);
+
+    log_success("Embedded file headers sent, body transmission scheduled");
+    return 0;
+}
+
+// Handle HTTP_WRITEABLE for embedded files
+int handle_embedded_file_writeable(struct lws* wsi) {
+    struct embedded_file_session_data* session_data = (struct embedded_file_session_data*)lws_wsi_user(wsi);
+    if (!session_data || session_data->headers_sent == 0 || session_data->body_sent == 1) {
+        return 0;
+    }
+
+    // Allocate buffer for data transmission
+    unsigned char *buf = malloc(LWS_PRE + session_data->size);
+    if (!buf) {
+        log_error("Failed to allocate buffer for embedded file transmission");
+        free(session_data);
+        lws_set_wsi_user(wsi, NULL);
+        return -1;
+    }
+
+    // Copy data to buffer
+    memcpy(buf + LWS_PRE, session_data->data, session_data->size);
+
+    // Write data
+    int write_result = lws_write(wsi, buf + LWS_PRE, session_data->size, LWS_WRITE_HTTP);
+
+    // Free the transmission buffer
+    free(buf);
+
+    if (write_result < 0) {
+        log_error("Failed to write embedded file data");
+        free(session_data);
+        lws_set_wsi_user(wsi, NULL);
+        return -1;
+    }
+
+    // Mark as sent and clean up
+    session_data->body_sent = 1;
+    free(session_data);
+    lws_set_wsi_user(wsi, NULL);
+
+    log_success("Embedded file served successfully");
+    return 0;
+}