/* SPDX-License-Identifier: Apache-2.0 */

/*
 * component.c - Example of writing a wasi-http Wasm component
 *
 * Copyright (C) Andrew Clayton
 * Copyright (C) F5, Inc.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>

#include "proxy.h"

#define ex(...) \
	do { \
		printf(__VA_ARGS__); \
		exit(EXIT_FAILURE); \
	} while (0);

static const struct {
	const char *method;
} http_method_map[] = {
	[WASI_HTTP_TYPES_METHOD_GET]	 = { "GET"     },
	[WASI_HTTP_TYPES_METHOD_HEAD]	 = { "HEAD"    },
	[WASI_HTTP_TYPES_METHOD_POST]    = { "POST"    },
	[WASI_HTTP_TYPES_METHOD_PUT]	 = { "PUT"     },
	[WASI_HTTP_TYPES_METHOD_DELETE]	 = { "DELETE"  },
	[WASI_HTTP_TYPES_METHOD_CONNECT] = { "CONNECT" },
	[WASI_HTTP_TYPES_METHOD_OPTIONS] = { "OPTIONS" },
	[WASI_HTTP_TYPES_METHOD_TRACE]	 = { "TRACE"   },
	[WASI_HTTP_TYPES_METHOD_PATCH]   = { "PATCH"   },
	[WASI_HTTP_TYPES_METHOD_OTHER]	 = { "OTHER"   }
};

void exports_wasi_http_incoming_handler_handle(
	exports_wasi_http_incoming_handler_own_incoming_request_t request,
	exports_wasi_http_incoming_handler_own_response_outparam_t response_out)
{
	bool ok;
	FILE *out;
	size_t size;
	char *out_ptr;
	char *ptr;
	char clen[32];
	wasi_http_types_borrow_incoming_request_t b_req;
	wasi_http_types_own_headers_t hdrs;
	wasi_http_types_borrow_fields_t b_hdrs;
	wasi_http_types_own_incoming_body_t r_body;
	wasi_http_types_borrow_incoming_body_t b_r_body;
	wasi_http_types_own_outgoing_response_t resp;
	wasi_http_types_borrow_outgoing_response_t b_resp;
	wasi_http_types_own_fields_t fields;
	wasi_http_types_borrow_fields_t b_fields;
	wasi_http_types_result_own_outgoing_response_error_code_t rerr = { };
	wasi_http_types_own_outgoing_body_t body;
	wasi_http_types_borrow_outgoing_body_t b_body;
	wasi_io_streams_own_output_stream_t out_stream;
	wasi_io_streams_borrow_output_stream_t b_out_stream;
	wasi_io_streams_list_u8_t stream_data;
	wasi_io_streams_stream_error_t stream_err;
	wasi_http_types_error_code_t http_err;
	wasi_http_types_header_error_t hdr_err;
	wasi_http_types_field_key_t key;
	wasi_http_types_field_value_t value;
	wasi_http_types_method_t method;
	wasi_http_types_list_tuple2_field_key_field_value_t fvk;
	wasi_http_types_own_input_stream_t in_stream;
	wasi_io_streams_borrow_input_stream_t b_in_stream;
	wasi_io_streams_list_u8_t data;
	wasi_io_streams_stream_error_t in_stream_err;
	proxy_string_t prstr;

	b_req = wasi_http_types_borrow_incoming_request(request);

	out = open_memstream(&out_ptr, &size);

#define BUF_ADD(fmt, ...) \
	fprintf(out, fmt, ##__VA_ARGS__);

	BUF_ADD("*** Welcome to WebAssembly with wasi-http / C ***\n\n");

	BUF_ADD("[Request Info]\n");
	wasi_http_types_method_incoming_request_path_with_query(b_req, &prstr);
	BUF_ADD("REQUEST_PATH = %.*s\n", (int)prstr.len, prstr.ptr);
	wasi_http_types_method_incoming_request_method(b_req, &method);
	BUF_ADD("METHOD       = %s\n", http_method_map[method.tag].method);
	ptr = memchr(prstr.ptr, '?', prstr.len);
	BUF_ADD("QUERY        = %.*s\n",
		ptr ? (int)(((char *)(prstr.ptr + prstr.len)) - ptr - 1) : 0,
		ptr ? ptr + 1 : "");

	BUF_ADD("\n[Request Headers]\n");
	hdrs = wasi_http_types_method_incoming_request_headers(b_req);
	b_hdrs = wasi_http_types_borrow_fields(hdrs);

	wasi_http_types_method_fields_entries(b_hdrs, &fvk);
	for (size_t i = 0; i < fvk.len; i++)
		BUF_ADD("%.*s = %.*s\n",
			(int)fvk.ptr[i].f0.len, fvk.ptr[i].f0.ptr,
			(int)fvk.ptr[i].f1.len, fvk.ptr[i].f1.ptr);

	wasi_http_types_list_tuple2_field_key_field_value_free(&fvk);

	ok = wasi_http_types_method_incoming_request_consume(b_req, &r_body);
	if (!ok)
		ex("wasi_http_types_method_incoming_request_consume() failed\n");
	b_r_body = wasi_http_types_borrow_incoming_body(r_body);
	ok = wasi_http_types_method_incoming_body_stream(b_r_body, &in_stream);
	if (!ok)
		ex("wasi_http_types_method_incoming_body_stream() failed\n");
	b_in_stream = wasi_io_streams_borrow_input_stream(in_stream);

	ok = wasi_io_streams_method_input_stream_read(b_in_stream,
						      8 * 1024*1024,
						      &data,
						      &in_stream_err);

	if (method.tag == WASI_HTTP_TYPES_METHOD_POST ||
	    method.tag == WASI_HTTP_TYPES_METHOD_PUT) {
		BUF_ADD("\n[%s data]\n",
			http_method_map[method.tag].method);
		BUF_ADD("%.*s\n", (int)data.len, data.ptr);
	}

	fclose(out);

	fields = wasi_http_types_constructor_fields();
	b_fields = wasi_http_types_borrow_fields(fields);

	proxy_string_set((proxy_string_t *)&key, "Content-Length");
	sprintf(clen, "%zu", size);
	proxy_string_set((proxy_string_t *)&value, clen);

	ok = wasi_http_types_method_fields_append(b_fields, &key, &value,
						  &hdr_err);
	if (!ok)
		ex("wasi_http_types_method_fields_append() failed\n");

	resp = wasi_http_types_constructor_outgoing_response(fields);

	b_resp = wasi_http_types_borrow_outgoing_response(resp);
	ok = wasi_http_types_method_outgoing_response_body(b_resp, &body);
	if (!ok)
		ex("wasi_http_types_method_outgoing_response_body() failed\n");
	b_body = wasi_http_types_borrow_outgoing_body(body);

	ok = wasi_http_types_method_outgoing_body_write(b_body, &out_stream);
	if (!ok)
		ex("wasi_http_types_method_outgoing_body_write() failed\n");
	b_out_stream = wasi_io_streams_borrow_output_stream(out_stream);

	stream_data.len = size;
	stream_data.ptr = (uint8_t *)out_ptr;
	ok = wasi_io_streams_method_output_stream_write(b_out_stream,
							&stream_data,
							&stream_err);
	if (!ok)
		ex("wasi_io_streams_method_output_stream_write() failed\n");

	free(out_ptr);

	wasi_http_types_static_response_outparam_set(response_out, &rerr);

	wasi_io_streams_output_stream_drop_borrow(out_stream);

	ok = wasi_http_types_static_outgoing_body_finish(body, NULL, &http_err);
	if (!ok)
		ex("wasi_http_types_static_outgoing_body_finish() failed\n");
}