From 1716af6c72d5d86d6e2a8c37d315a8219f7126b9 Mon Sep 17 00:00:00 2001
From: cpq <valenok@gmail.com>
Date: Thu, 24 Dec 2020 16:52:12 +0000
Subject: [PATCH] Add HTTP client code

---
 examples/esp32/Makefile    |  7 ++++++-
 examples/esp32/README.md   |  9 +++++++++
 examples/esp32/main/main.c | 34 ++++++++++++++++++++++++++--------
 3 files changed, 41 insertions(+), 9 deletions(-)

diff --git a/examples/esp32/Makefile b/examples/esp32/Makefile
index 85019156..bdf03ca6 100644
--- a/examples/esp32/Makefile
+++ b/examples/esp32/Makefile
@@ -3,8 +3,13 @@ ROOTDIR = $(realpath $(CURDIR)/../..)
 
 all: example
 
-example:
+example: main/main.c Makefile
 	docker run --rm -v $(ROOTDIR):$(ROOTDIR) -w $(THISDIR) espressif/idf idf.py build
 
+COMPORT ?= /dev/cu.SLAB_USBtoUART
+ESPTOOL ?= esptool.py
+flash:
+	cd build && $(ESPTOOL) --chip esp32 -p $(COMPORT) -b 460800 --before=default_reset --after=hard_reset write_flash --flash_mode dio --flash_freq 40m --flash_size 2MB 0x8000 partition_table/partition-table.bin 0x1000 bootloader/bootloader.bin 0x10000 mongoose-esp32-example.bin
+
 clean:
 	rm -rf $(PROG) *.o *.dSYM *.gcov *.gcno *.gcda *.obj *.exe *.ilk *.pdb mongoose mongoose_* mongoose.* build sdkconfig
diff --git a/examples/esp32/README.md b/examples/esp32/README.md
index 0daba123..b44dfc43 100644
--- a/examples/esp32/README.md
+++ b/examples/esp32/README.md
@@ -17,3 +17,12 @@ To build this application, follow these steps:
   make
   ```
 
+# Flashing built firmware
+
+If you have a real board to flash to, you can flash a built firmware.
+First, make sure to have `esptool.py` script installed on your workstation.
+Then, connect the board to your workstation and run the following command:
+
+```sh
+make flash COMPORT=YOUR_USB_PORT
+```
diff --git a/examples/esp32/main/main.c b/examples/esp32/main/main.c
index 277841c1..5b9e4dc3 100644
--- a/examples/esp32/main/main.c
+++ b/examples/esp32/main/main.c
@@ -3,23 +3,41 @@
 
 #include "mongoose.h"
 
-#define WIFI_SSID "MY_WIFI_NETWORK"
-#define WIFI_PASS "MY_WIFI_PASSWORD"
-#define LISTENING_ADDR "http://0.0.0.0:80"
+#define WIFI_SSID "VMDF554B9"     // SET THIS!
+#define WIFI_PASS "Mp7wjmamPafa"  // SET THIS!
 
-// Event handler for an accepted connection
+#define SERVER_URL "http://0.0.0.0:80"
+#define CLIENT_URL "http://info.cern.ch"
+
+// Event handler for an server (accepted) connection
 static void cb(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
   if (ev == MG_EV_HTTP_MSG) {
-    mg_http_reply(c, 200, "", "Hello from ESP32!");
+    mg_http_reply(c, 200, "", "Hello from ESP32!\n");
+  }
+}
+
+// Event handler for a client connection - fetch the first web page in history
+// To enable TLS for HTTP,
+//   1. Copy "ca.pem" file to the ESP32 flash FS
+//   2. Add TLS init snippet for the connection, see examples/http-client
+static void cb2(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
+  if (ev == MG_EV_CONNECT) {
+    struct mg_str s = mg_url_host(CLIENT_URL);
+    mg_printf(c, "GET / HTTP/1.0\r\nHost: %.*s\r\n\r\n", (int) s.len, s.ptr);
+  } else if (ev == MG_EV_HTTP_MSG) {
+    struct mg_http_message *hm = ev_data;  // Print HTTP response
+    LOG(LL_INFO, ("Fetched:\n%.*s", (int) hm->message.len, hm->message.ptr));
+    c->is_closing = 1;
   }
 }
 
 // Called after we're connected to WiFi network
-static void start_server(void) {
+static void run_mongoose(void) {
   struct mg_mgr mgr;
   mg_log_set("3");
   mg_mgr_init(&mgr);
-  mg_http_listen(&mgr, LISTENING_ADDR, cb, &mgr);
+  mg_http_listen(&mgr, SERVER_URL, cb, &mgr);    // Listening server
+  mg_http_connect(&mgr, CLIENT_URL, cb2, &mgr);  // Example client
   LOG(LL_INFO, ("Starting Mongoose web server v%s", MG_VERSION));
   for (;;) mg_mgr_poll(&mgr, 1000);
   mg_mgr_free(&mgr);
@@ -32,5 +50,5 @@ void app_main(void) {
   wifi_init(WIFI_SSID, WIFI_PASS);
 
   // Done connecting to WiFi, now start HTTP server
-  start_server();
+  run_mongoose();
 }