#define _POSIX_C_SOURCE 200809L

#include <ncurses.h>
#include <time.h>
#include <signal.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <curl/curl.h>
#include <stdio.h>
#include <stdlib.h>

static volatile sig_atomic_t running = 1;
static volatile sig_atomic_t resized = 0;

static void handle_sigint(int sig) { (void)sig; running = 0; }
static void handle_winch(int sig) { (void)sig; resized = 1; }

/* ---------------- Config ---------------- */
typedef struct {
    char api_key[128];
    char location[64];
    char units[16];
} config_t;

/* Simple TOML parser for [weather] section */
static bool load_config_toml(config_t *cfg, const char *path) {
    FILE *f = fopen(path, "r");
    if (!f) return false;

    bool in_weather_section = false;
    while (!feof(f)) {
        char line[256];
        if (!fgets(line, sizeof(line), f)) break;

        /* Remove comments */
        char *hash = strchr(line, '#');
        if (hash) *hash = '\0';

        /* Strip leading/trailing whitespace */
        char *start = line;
        while (*start && (*start == ' ' || *start == '\t')) start++;
        char *end = start + strlen(start) - 1;
        while (end > start && (*end == ' ' || *end == '\t' || *end == '\n' || *end == '\r')) *end-- = '\0';

        if (strlen(start) == 0) continue;

        if (start[0] == '[' && start[strlen(start)-1] == ']') {
            if (strncmp(start+1, "weather", 7) == 0) in_weather_section = true;
            else in_weather_section = false;
            continue;
        }

        if (!in_weather_section) continue;

        char key[32], val[128];
        if (sscanf(start, "%31[^=]= \"%127[^\"]\"", key, val) == 2) {
            char *k_end = key + strlen(key) - 1;
            while (k_end > key && (*k_end == ' ' || *k_end == '\t')) *k_end-- = '\0';

            if (strcmp(key, "api_key") == 0) strncpy(cfg->api_key, val, sizeof(cfg->api_key)-1);
            else if (strcmp(key, "location") == 0) strncpy(cfg->location, val, sizeof(cfg->location)-1);
            else if (strcmp(key, "units") == 0) strncpy(cfg->units, val, sizeof(cfg->units)-1);
        }
    }

    fclose(f);
    return cfg->api_key[0] && cfg->location[0];
}

/* ---------------- libcurl callback ---------------- */
struct mem {
    char *data;
    size_t size;
};

static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *userdata) {
    struct mem *m = (struct mem *)userdata;
    size_t total = size * nmemb;

    if (m->size + total < 10240) {
        memcpy(m->data + m->size, ptr, total);
        m->size += total;
        m->data[m->size] = '\0';
    }
    return total;
}

/* ---------------- Fetch temperature ---------------- */
bool fetch_temp_owm(const config_t *cfg, char *out, size_t out_size) {
    if (!cfg || !out) return false;

    CURL *curl = curl_easy_init();
    if (!curl) return false;

    char url[512];
    snprintf(url, sizeof(url),
             "https://api.openweathermap.org/data/2.5/weather?q=%s&units=%s&appid=%s",
             cfg->location, cfg->units[0] ? cfg->units : "metric", cfg->api_key);

    char buffer[10240] = {0};
    struct mem m = { buffer, 0 };

    curl_easy_setopt(curl, CURLOPT_URL, url);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_cb);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &m);
    curl_easy_setopt(curl, CURLOPT_USERAGENT, "tty-clock-weather/1.0");

    CURLcode res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);

    if (res != CURLE_OK) return false;

    char *p = strstr(buffer, "\"temp\":");
    if (!p) return false;
    p += 7;

    double temp = atof(p);
    char unit = (cfg->units[0] && strcmp(cfg->units, "imperial") == 0) ? 'F' : 'C';
    snprintf(out, out_size, "%.0f°%c %s", temp, unit, cfg->location);

    return true;
}

/* ---------------- Main ---------------- */
int main(int argc, char **argv) {
bool twelve_hour = false;
bool human_date = false;
bool quiet = false;
bool hide_temp = false;
bool force_c = false;
bool force_f = false;

/* Parse CLI flags FIRST */

for (int i = 1; i < argc; i++) {
    if (strcmp(argv[i], "--help") == 0) {
        goto show_help;
    }
    if (argv[i][0] != '-') continue;

    for (int j = 1; argv[i][j]; j++) {
        switch (argv[i][j]) {
            case 't': twelve_hour = true; break;
            case 'H': human_date = true; break;
            case 'q': quiet = true; break;
            case 'T': hide_temp = true; break;
            case 'C': force_c = true; break;
            case 'F': force_f = true; break;

            case 'h':
                goto show_help;

            default:
                printf("Unknown flag: -%c\n", argv[i][j]);
                return 1;
        }
    }
}

/* NOW load config */

config_t cfg = {0};
char config_path[512];
snprintf(config_path, sizeof(config_path), "%s/.config/cclock/config", getenv("HOME"));

if (!load_config_toml(&cfg, config_path)) {
    printf("Failed to load config from %s\n", config_path);
    return 1;
}

/* NOW apply overrides */

if (force_c) {
    strncpy(cfg.units, "metric", sizeof(cfg.units) - 1);
    cfg.units[sizeof(cfg.units) - 1] = '\0';
}
else if (force_f) {
    strncpy(cfg.units, "imperial", sizeof(cfg.units) - 1);
    cfg.units[sizeof(cfg.units) - 1] = '\0';
}

for (int i = 1; i < argc; i++) {
    if (argv[i][0] != '-') continue;

    for (int j = 1; argv[i][j]; j++) {
        switch (argv[i][j]) {
            case 't':
                twelve_hour = true;
                break;

            case 'T':
                hide_temp = true;
                break;

            case 'C':
                force_c = true;
                break;

            case 'F':
                force_f = true;
                break;

            case 'H':
                human_date = true;
                break;

            case 'q':
                quiet = true;
                break;

            case 'h':
                goto show_help;

            default:
                printf("Unknown flag: -%c\n", argv[i][j]);
                return 1;
        }
    }
}

    signal(SIGINT, handle_sigint);
    signal(SIGWINCH, handle_winch);

    initscr();
    cbreak();
    noecho();
    curs_set(0);
    keypad(stdscr, TRUE);
    nodelay(stdscr, TRUE);

    curl_global_init(CURL_GLOBAL_DEFAULT);

    char time_buf[16], date_buf[15], temp_buf[64];
    time_t last_fetch = 0;
    const int refresh_interval = 600; /* 10 minutes */

    if (!fetch_temp_owm(&cfg, temp_buf, sizeof(temp_buf)))
        strncpy(temp_buf, "N/A", sizeof(temp_buf));

    while (running) {
        if (resized) {
            endwin();
            refresh();
            clear();
            resized = 0;
        }

        clear();

        time_t now = time(NULL);
        struct tm *tm_now = localtime(&now);
        if (!tm_now) break;

        const char *time_fmt = twelve_hour ? "%I:%M %p" : "%H:%M";
        strftime(time_buf, sizeof(time_buf), time_fmt, tm_now);

        const char *date_fmt = human_date ? "%A %d, %b" : "%m/%d/%Y";
        strftime(date_buf, sizeof(date_buf), date_fmt, tm_now);

        if (difftime(now, last_fetch) >= refresh_interval) {
            if (!fetch_temp_owm(&cfg, temp_buf, sizeof(temp_buf)))
                strncpy(temp_buf, "N/A", sizeof(temp_buf));
            last_fetch = now;
        }

        int rows, cols;
        getmaxyx(stdscr, rows, cols);

        int time_x = (cols - strlen(time_buf)) / 2;
        int y_mid = rows / 2;
        attron(A_BOLD);
        mvprintw(y_mid, time_x, "%s", time_buf);
        attroff(A_BOLD);

        int date_x = (cols - strlen(date_buf)) / 2;
        mvprintw(y_mid + 1, date_x, "%s", date_buf);

        if (!hide_temp) {
            int temp_x = (cols - strlen(temp_buf)) / 2;
            mvprintw(y_mid + 2, temp_x, "%s", temp_buf);
        }

        if (!quiet)
            mvprintw(rows - 1, 0, "Press 'q' to quit");

        refresh();

        int ch = getch();
        if (ch == 'q' || ch == 'Q') break;

        sleep(1);
    }

    curl_global_cleanup();
    endwin();

    /* Help/Usage output */
    show_help:

        printf("Usage: %s [-HqTtCF]\n\n", argv[0]);
        printf("Options:\n");
        printf("  -t         Use 12-hour time format\n");
        printf("  -H         Human-readable date (\"Tuesday 16, Feb\")\n");
        printf("  -q         Hide \"Press q to quit\" footer\n");
        printf("  -T         Hide temperature display\n");
        printf("  -C         Force Celsius\n");
        printf("  -F         Force Fahrenheit\n");
        printf("  -h,--help  Show this help\n");
    return 0;
}