Add HTTP server

main/CMakeLists.txt

@@ -2,5 +2,6 @@ idf_component_register(
   SRCS
     "inkpot.c"
     "paper.c"
+    "server.c"
   INCLUDE_DIRS "."
 )

main/inkpot.c

@@ -15,6 +15,7 @@
 #include <dirent.h>
 
 #include "paper.h"
+#include "server.h"
 
 #define WIFI_SCAN_LIST_SIZE 10
 #define LUA_FILE_PATH "/assets"
@@ -96,7 +97,7 @@ void run_lua_file(const char *file_name, const char *test_name) {
 }
 
 // Function to run an embedded Lua script
-void run_embedded_lua_test(const char *lua_script, const char *test_name) {
+void run_lua_string(const char *lua_script, const char *test_name) {
     ESP_LOGI(TAG, "Starting Lua test: %s", test_name);
 
     log_memory_usage("Start of test");
@@ -176,19 +177,96 @@ void scan_wifi_networks(void) {
     ESP_LOGI(TAG, "Wi-Fi scan completed.");
 }
 
-void app_main(void) {
-
+// HTTP Server
 
+#define WRITE_HEADER(req, buffer, name, format, src) \
+    sprintf(buffer, format, src);                    \
+    ESP_ERROR_CHECK(httpd_resp_set_hdr(req, name, buffer));
 
+static esp_err_t http_index(httpd_req_t* req) {
+    // TODO: Serve HTML file with form POSTing to `/draw`
+    const char* response = "Hello world!\n";
+    httpd_resp_set_type(req, "text/plain");
+    httpd_resp_set_status(req, "200");
+    httpd_resp_send(req, response, HTTPD_RESP_USE_STRLEN);
+    return ESP_OK;
+}
 
+esp_err_t http_draw(httpd_req_t* req) {
+    // READING STREAM
+    int req_size = req->content_len;
+    char* content = (char*)heap_caps_malloc(req_size, MALLOC_CAP_SPIRAM);
+    if (content == NULL) {
+        char msg[50];
+        sprintf(msg, "Failed to allocate %d chars\n", req_size);
+        httpd_resp_send_err(req, HTTPD_500_INTERNAL_SERVER_ERROR, msg);
+        return ESP_ERR_INVALID_ARG;
     }
+    int current_pos = 0;
+    int amount_recieved;
+    while ((amount_recieved = httpd_req_recv(req, (content + current_pos), req_size)) > 0) {
+        ESP_LOGI(__FUNCTION__, "Read %d bytes\n", amount_recieved);
+        current_pos += amount_recieved;
+    }
+    if (amount_recieved < 0) {
+        char msg[50];
+        heap_caps_free(content);
+        ESP_LOGE(msg, "Failed to read bytes. Error code %d\n", amount_recieved);
+        httpd_resp_send_err(req, HTTPD_500_INTERNAL_SERVER_ERROR, msg);
+        return ESP_ERR_INVALID_ARG;
+    }
+    ESP_LOGI(__FUNCTION__, "Done reading %d bytes out of %d\n", current_pos, req_size);
 
+    // TODO: Error handling
+    run_lua_string(content, "E-Paper Script via HTTP");
+    heap_caps_free(content);
 
+    // Done reading
+    char response[100];
+    sprintf(
+        response, "script drawn!"
+    );
+    httpd_resp_set_type(req, "text/plain");
+    httpd_resp_set_status(req, "200");
+    httpd_resp_send(req, response, HTTPD_RESP_USE_STRLEN);
+    return ESP_OK;
+}
+
+void register_http_routes(httpd_handle_t server) {
+    {
+        httpd_uri_t uri
+            = { .uri = "/", .method = HTTP_GET, .handler = http_index, .user_ctx = NULL };
+        httpd_register_uri_handler(server, &uri);
+    }
+    {
+        httpd_uri_t uri
+            = { .uri = "/draw", .method = HTTP_POST, .handler = http_draw, .user_ctx = NULL };
+        httpd_register_uri_handler(server, &uri);
+    }
+}
+
+// init
+
+void app_main(void) {
     // Initialize and mount the filesystem
     init_filesystem();
 
+    // Initialize NVS, needed for wifi
+    esp_err_t ret = nvs_flash_init();
+    if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
+        ESP_ERROR_CHECK(nvs_flash_erase());
+        ret = nvs_flash_init();
+    }
+    ESP_ERROR_CHECK(ret);
+
+    // Set up HTTP server
+    httpd_handle_t server = get_server();
+    if (server != NULL) {
+        register_http_routes(server);
+    }
+
     // Run script in assets/epaper.lua
-    run_lua_file("epaper.lua", "E-Paper Script");
+    run_lua_file("epaper.lua", "E-Paper Startup Script");
 
     ESP_LOGI(TAG, "End of testing application.");
 

main/server.c

@@ -0,0 +1,49 @@
+#include "server.h"
+#include "settings.h"
+
+httpd_handle_t get_server(void);
+
+static void wifi_init_sta(void) {
+    // Initialize the ESP-NETIF
+    esp_netif_init();
+    esp_event_loop_create_default();
+
+    // Create default event loop
+    esp_netif_create_default_wifi_sta();
+
+    // Initialize the Wi-Fi driver
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+
+    // Set Wi-Fi mode to station
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+
+    // Configure Wi-Fi connection
+    wifi_config_t wifi_config = {
+        // TODO: Allow setting SSID at boot or build time
+        // For some reason I could not get https://cmake.org/cmake/help/latest/command/add_compile_definitions.html#command:add_compile_definitions to work
+        .sta = {
+            .ssid = WIFI_SSID,
+            .password = WIFI_PASS,
+        },
+    };
+
+    // Set the Wi-Fi configuration
+    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config));
+    ESP_ERROR_CHECK(esp_wifi_start());
+    ESP_ERROR_CHECK(esp_wifi_connect());
+}
+
+httpd_handle_t start_webserver(void) {
+    httpd_config_t config = HTTPD_DEFAULT_CONFIG();
+    config.lru_purge_enable = true;
+
+    httpd_handle_t server = NULL;
+    ESP_ERROR_CHECK(httpd_start(&server, &config));
+    return server;
+}
+
+httpd_handle_t get_server(void) {
+    wifi_init_sta();
+    return start_webserver();
+}

main/server.h

@@ -0,0 +1,19 @@
+#ifndef SERVER_H_
+#define SERVER_H_
+
+#include <stdio.h>
+#include <string.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "esp_event.h"
+#include "esp_log.h"
+#include "nvs_flash.h"
+#include "esp_wifi.h"
+#include "esp_netif.h"
+#include "esp_http_server.h"
+
+// #include "settings.h"
+
+httpd_handle_t get_server(void);
+
+#endif // SERVER_H_

main/settings.h

@@ -0,0 +1,7 @@
+#ifndef SETTINGS_H_
+#define SETTINGS_H_
+
+#define WIFI_SSID ""
+#define WIFI_PASS ""
+
+#endif // SETTINGS_H_