#include <stdio.h>
#include <stdint.h>
#include <winsock2.h>
#include <ws2tcpip.h>

#define BUFFER_SIZE (1024 * 1024)

void simple_http_ok(char *response, size_t *response_len);

int main() {

        printf("hello world!~\n");

        int result = 0;
        WSADATA wsaData = {0};
        struct sockaddr_in service;

        const char* address = "127.0.0.1";
        int port = 8080;

        result = WSAStartup(MAKEWORD(2, 2), &wsaData);
        if (result != 0) {
                printf("WSAStartup failed: %d\n", result);
                return 1;
        }

        SOCKET sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
        if (sock == INVALID_SOCKET) {
                printf("failed to create socket! (%d)\n", WSAGetLastError());
                WSACleanup();
                return 1;
        }

        printf("socket created successfully!\n");

        service.sin_family = AF_INET;
        service.sin_addr.s_addr = inet_addr(address);
        service.sin_port = htons(port);

        if (bind(sock, (SOCKADDR*) &service, sizeof(service)) == SOCKET_ERROR) {
                closesocket(sock);
                printf("failed to bind to %s:%d: %ld\n", address, port, WSAGetLastError());
                WSACleanup();
                return 1;
        }

        /*
        result = connect(sock, (SOCKADDR*) &service, sizeof(client_service));
        if (result == SOCKET_ERROR) {
                closesocket(sock);
                printf("unable to connect to the server: %ld\n", WSAGetLastError());
                WSACleanup();
                return 1;
        }
        */

        if (listen(sock, 1) == SOCKET_ERROR) {
                closesocket(sock);
                printf("failed to bind to %s:%d: %ld\n", address, port, WSAGetLastError());
                WSACleanup();
                return 1;
        }

        /*
        char address[INET_ADDRSTRLEN];
        InetNtop(AF_INET, &(service.sin_addr.s_addr), address, INET_ADDRSTRLEN);
        ntohs(service.sin_port)
        */
        printf("now listening on %s:%d!\n", address, port);

        char running = 1;

        do {
                SOCKET accept_sock = accept(sock, NULL, NULL);
                if (accept_sock == INVALID_SOCKET) {
                        closesocket(sock);
                        printf("failed to accept socket connection: %ld\n", WSAGetLastError());
                        WSACleanup();
                        return 1;
                } else {
                        printf("client connected!\n");
                }

                char recvbuf[512];
                int received = 0;
                do {
                        received = recv(accept_sock, recvbuf, 512, 0);
                        char end[] = "\r\n\r\n";
                        char lastfour[4];

                        if (received > 0) {
                                printf("bytes received: %d\n", received);
                                printf("< ");
                                for (int i = 0; i < received; i++) {
                                        printf("%c", recvbuf[i]);
                                        if (recvbuf[i] == '\n') {
                                                printf("< ");
                                        }
                                        for (int i = 0; i < 3; i++) {
                                                lastfour[i] = lastfour[i + 1];
                                        }
                                        lastfour[3] = recvbuf[i];
                                }

                                char matches = 1;

                                for (int i = 0; i < 4; i++) {
                                        if (lastfour[i] != end[i]) {
                                                matches = 0;
                                                break;
                                        }
                                }

                                if (matches) break;
                        } else if (received == 0) {
                                printf("connection closed.\n");
                        } else {
                                printf("recv failed: %d\n", WSAGetLastError());
                        }
                } while (received > 0);

                char *response = (char *)malloc(BUFFER_SIZE * 2 * sizeof(char));
                size_t response_len;
                simple_http_ok(response, &response_len);

                send(accept_sock, response, response_len, 0);

                free(response);

                result = closesocket(accept_sock);
                if (result == SOCKET_ERROR) {
                        printf("failed to close socket properly: %d\n", WSAGetLastError());
                        closesocket(sock);
                        WSACleanup();
                        return 1;
                }
        } while (running);

        // close responsibly! <3
        result = closesocket(sock);
        if (result == SOCKET_ERROR) {
                printf("failed to close socket properly: %d\n", WSAGetLastError());
                WSACleanup();
                return 1;
        }

        return 0;

}

void simple_http_ok(char *response, size_t *response_len) {
        // build header
        char *header = (char *)malloc(BUFFER_SIZE * sizeof(char));
        snprintf(header, BUFFER_SIZE,
                "HTTP/1.1 200 OK\r\n"
                "Content-Type: text/plain; charset=utf-8\r\n"
                "Content-Length: 9\r\n"
                "\r\n"
                "meow 😺");

        *response_len = 0;
        memcpy(response, header, strlen(header));
        *response_len += strlen(header);

        free(header);
}