#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include <pwd.h>

Config g_cfg;

static char g_cfg_path[512] = "";

static void set_defaults(void) {
    memset(&g_cfg, 0, sizeof(g_cfg));
    g_cfg.port = 8787;
    strncpy(g_cfg.bind_iface,    "wg0-mullvad",          sizeof(g_cfg.bind_iface)-1);
    strncpy(g_cfg.iptv_api,      "http://newlogin.freeopened.com/player_api.php", sizeof(g_cfg.iptv_api)-1);
    strncpy(g_cfg.dl_dir_tv,     "/mnt/media/TV",        sizeof(g_cfg.dl_dir_tv)-1);
    strncpy(g_cfg.dl_dir_mov,    "/mnt/media/Movies",    sizeof(g_cfg.dl_dir_mov)-1);
    strncpy(g_cfg.template_dir,  "/usr/local/share/iptv-dl", sizeof(g_cfg.template_dir)-1);
    strncpy(g_cfg.data_dir,      "/var/lib/iptv-dl",     sizeof(g_cfg.data_dir)-1);
    g_cfg.max_recv_speed = 20L * 1024 * 1024; /* 20 MiB/s */
}

/* minimal JSON string field parser — no full JSON lib dependency */
static void cfg_read_str(const char *json, const char *key, char *dst, size_t dsz) {
    char needle[128]; snprintf(needle, sizeof(needle), "\"%s\"", key);
    const char *p = strstr(json, needle);
    if (!p) return;
    p += strlen(needle);
    while (*p == ' ' || *p == ':') p++;
    if (*p != '"') return;
    p++;
    size_t i = 0;
    while (*p && *p != '"' && i < dsz-1) {
        if (*p == '\\' && *(p+1)) { p++; dst[i++] = *p++; }
        else dst[i++] = *p++;
    }
    dst[i] = 0;
}

static int cfg_read_int(const char *json, const char *key, int def) {
    char needle[128]; snprintf(needle, sizeof(needle), "\"%s\"", key);
    const char *p = strstr(json, needle);
    if (!p) return def;
    p += strlen(needle);
    while (*p == ' ' || *p == ':') p++;
    if (*p < '0' || *p > '9') return def;
    return atoi(p);
}

static long cfg_read_long(const char *json, const char *key, long def) {
    char needle[128]; snprintf(needle, sizeof(needle), "\"%s\"", key);
    const char *p = strstr(json, needle);
    if (!p) return def;
    p += strlen(needle);
    while (*p == ' ' || *p == ':') p++;
    if (*p < '0' || *p > '9') return def;
    return atol(p);
}

static int try_load(const char *path) {
    FILE *f = fopen(path, "r");
    if (!f) return 0;
    fseek(f, 0, SEEK_END); long sz = ftell(f); fseek(f, 0, SEEK_SET);
    char *buf = malloc(sz + 1);
    if (!buf) { fclose(f); return 0; }
    fread(buf, 1, sz, f); buf[sz] = 0; fclose(f);

    cfg_read_str(buf, "bind_iface",      g_cfg.bind_iface,      sizeof(g_cfg.bind_iface));
    cfg_read_str(buf, "iptv_api",        g_cfg.iptv_api,        sizeof(g_cfg.iptv_api));
    cfg_read_str(buf, "iptv_user",       g_cfg.iptv_user,       sizeof(g_cfg.iptv_user));
    cfg_read_str(buf, "iptv_pass",       g_cfg.iptv_pass,       sizeof(g_cfg.iptv_pass));
    cfg_read_str(buf, "stream_base",     g_cfg.stream_base,     sizeof(g_cfg.stream_base));
    cfg_read_str(buf, "dl_dir_tv",       g_cfg.dl_dir_tv,       sizeof(g_cfg.dl_dir_tv));
    cfg_read_str(buf, "dl_dir_mov",      g_cfg.dl_dir_mov,      sizeof(g_cfg.dl_dir_mov));
    cfg_read_str(buf, "discord_webhook", g_cfg.discord_webhook, sizeof(g_cfg.discord_webhook));
    cfg_read_str(buf, "jellyfin_url",    g_cfg.jellyfin_url,    sizeof(g_cfg.jellyfin_url));
    cfg_read_str(buf, "jellyfin_token",  g_cfg.jellyfin_token,  sizeof(g_cfg.jellyfin_token));
    cfg_read_str(buf, "template_dir",    g_cfg.template_dir,    sizeof(g_cfg.template_dir));
    cfg_read_str(buf, "data_dir",        g_cfg.data_dir,        sizeof(g_cfg.data_dir));
    g_cfg.port           = cfg_read_int(buf,  "port",            g_cfg.port);
    g_cfg.max_recv_speed = cfg_read_long(buf, "max_recv_speed",  g_cfg.max_recv_speed);

    free(buf);
    strncpy(g_cfg_path, path, sizeof(g_cfg_path)-1);
    return 1;
}

const char *config_load(const char *explicit_path) {
    set_defaults();

    /* 1. explicit argument */
    if (explicit_path && *explicit_path) {
        if (try_load(explicit_path)) return g_cfg_path;
        fprintf(stderr, "iptv-dl: warning: cannot read config '%s', using defaults\n", explicit_path);
        return NULL;
    }

    /* 2. env var */
    const char *env = getenv("IPTV_DL_CONFIG");
    if (env && *env) {
        if (try_load(env)) return g_cfg_path;
    }

    /* 3. ~/.iptv-downloader/config.json */
    char home_cfg[512];
    const char *home = getenv("HOME");
    if (!home) {
        struct passwd *pw = getpwuid(getuid());
        if (pw) home = pw->pw_dir;
    }
    if (home) {
        snprintf(home_cfg, sizeof(home_cfg), "%s/.iptv-downloader/config.json", home);
        if (try_load(home_cfg)) return g_cfg_path;
    }

    /* 4. /etc/iptv-downloader/config.json */
    if (try_load("/etc/iptv-downloader/config.json")) return g_cfg_path;

    /* 5. defaults only */
    fprintf(stderr, "iptv-dl: no config file found, using built-in defaults\n");
    return NULL;
}

void config_save(void) {
    if (!g_cfg_path[0]) {
        fprintf(stderr, "iptv-dl: no config path set, cannot save\n");
        return;
    }
    FILE *f = fopen(g_cfg_path, "w");
    if (!f) { perror("config_save"); return; }
    fprintf(f, "{\n");
    fprintf(f, "  \"port\": %d,\n", g_cfg.port);
    fprintf(f, "  \"bind_iface\": \"%s\",\n", g_cfg.bind_iface);
    fprintf(f, "  \"iptv_api\": \"%s\",\n", g_cfg.iptv_api);
    fprintf(f, "  \"iptv_user\": \"%s\",\n", g_cfg.iptv_user);
    fprintf(f, "  \"iptv_pass\": \"%s\",\n", g_cfg.iptv_pass);
    fprintf(f, "  \"stream_base\": \"%s\",\n", g_cfg.stream_base);
    fprintf(f, "  \"dl_dir_tv\": \"%s\",\n", g_cfg.dl_dir_tv);
    fprintf(f, "  \"dl_dir_mov\": \"%s\",\n", g_cfg.dl_dir_mov);
    fprintf(f, "  \"discord_webhook\": \"%s\",\n", g_cfg.discord_webhook);
    fprintf(f, "  \"jellyfin_url\": \"%s\",\n", g_cfg.jellyfin_url);
    fprintf(f, "  \"jellyfin_token\": \"%s\",\n", g_cfg.jellyfin_token);
    fprintf(f, "  \"template_dir\": \"%s\",\n", g_cfg.template_dir);
    fprintf(f, "  \"data_dir\": \"%s\",\n", g_cfg.data_dir);
    fprintf(f, "  \"max_recv_speed\": %ld\n", g_cfg.max_recv_speed);
    fprintf(f, "}\n");
    fclose(f);
}

void config_dump(void) {
    fprintf(stderr,
        "iptv-dl config:\n"
        "  port=%d bind_iface=%s\n"
        "  iptv_api=%s user=%s\n"
        "  stream_base=%s\n"
        "  dl_dir_tv=%s dl_dir_mov=%s\n"
        "  template_dir=%s data_dir=%s\n"
        "  max_recv_speed=%ld B/s\n",
        g_cfg.port, g_cfg.bind_iface,
        g_cfg.iptv_api, g_cfg.iptv_user,
        g_cfg.stream_base,
        g_cfg.dl_dir_tv, g_cfg.dl_dir_mov,
        g_cfg.template_dir, g_cfg.data_dir,
        g_cfg.max_recv_speed);
}

void config_history_path(char *buf, size_t n) {
    snprintf(buf, n, "%s/history.json", g_cfg.data_dir);
}

void config_notif_path(char *buf, size_t n) {
    snprintf(buf, n, "%s/notifications.json", g_cfg.data_dir);
}