#include <arpa/inet.h>
#include <json-c/json.h>
#include <signal.h>
#include <threads.h>

#include "logger.c"

#define BACKLOG 10

struct Client {
    int fd;
    struct sockaddr_in addr;
};

void sig_handler(int signo) {
    log_warn("Signal %d received, shutting down data server", signo);
    exit(0);
}

void respond_name(int client_fd) {
    log_info("Client requested simulation name");

    struct json_object *sim_name = json_object_new_object();
    json_object_object_add(sim_name, "name", json_object_new_string(NAME));
    json_object_to_fd(client_fd, sim_name, JSON_C_TO_STRING_PRETTY);
    json_object_put(sim_name);
}

void respond_opts(int client_fd) {
    log_info("Client requested simulation options");

    struct json_object *sim_opts = json_object_from_file(SIM_OPTS);
    json_object_to_fd(client_fd, sim_opts, JSON_C_TO_STRING_PRETTY);
    json_object_put(sim_opts);
}

void respond_hash(int client_fd) {
    log_info("Client requested git hash");

    char buff[41] = { 0 };
    FILE *pipe = popen("git rev-parse HEAD", "r");
    fread(buff, sizeof(char), 40, pipe);
    pclose(pipe);

    struct json_object *git_hash = json_object_new_object();
    json_object_object_add(git_hash, "hash", json_object_new_string(buff));
    json_object_to_fd(client_fd, git_hash, JSON_C_TO_STRING_PRETTY);
    json_object_put(git_hash);
}

int handle_client(struct Client *client) {
    assert(client);

    char client_ip[INET_ADDRSTRLEN];
    inet_ntop(AF_INET, &client->addr.sin_addr, client_ip, INET_ADDRSTRLEN);
    log_info("Client connected: %s:%d", client_ip, ntohs(client->addr.sin_port));

    char request = '\0';
    recv(client->fd, &request, 1, 0);

    switch (request) {
    case REQUEST_NAME:
        respond_name(client->fd);
        break;
    case REQUEST_OPTS:
        respond_opts(client->fd);
        break;
    case REQUEST_HASH:
        respond_hash(client->fd);
        break;
    default:
        log_warn("Client made invalid request");
    }

    log_info("Client disconnected: %s:%d", client_ip, ntohs(client->addr.sin_port));
    close(client->fd);

    free(client);
    return 0;
}

int main(void) {
    signal(SIGINT, sig_handler);
    signal(SIGTERM, sig_handler);

    log_info("Initializing salis data server");
    int opt = 1;
    int server_fd = socket(AF_INET, SOCK_STREAM, 0);
    setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));

    log_info("Binding to port: %d", PORT);
    struct sockaddr_in server_addr = { 0 };
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;
    server_addr.sin_port = htons(PORT);
    bind(server_fd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr_in));

    log_info("Listening...");
    listen(server_fd, BACKLOG);

    while (true) {
        struct Client *client = calloc(1, sizeof(struct Client));
        socklen_t client_len = sizeof(struct sockaddr_in);
        client->fd = accept(server_fd, (struct sockaddr *)&client->addr, &client_len);

        thrd_t thrd;
        thrd_create(&thrd, (thrd_start_t)handle_client, client);
        thrd_detach(thrd);
    }

    close(server_fd);
    return 0;
}