#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <libgen.h>

#include "toml.h"

static char *trim(char *s) {
    while (*s == ' ' || *s == '\t' || *s == '\n' || *s == '\r') s++;
    char *end = s + strlen(s);
    while (end > s && (end[-1] == ' ' || end[-1] == '\t' || end[-1] == '\n' || end[-1] == '\r')) end--;
    *end = '\0';
    return s;
}

static void config_ensure_capacity(config_t *cfg) {
    if (cfg->count < cfg->capacity) return;
    int newcap = cfg->capacity ? cfg->capacity * 2 : 16;
    binding_t *nb = realloc(cfg->items, newcap * sizeof(binding_t));
    if (!nb) return;
    cfg->items = nb;
    cfg->capacity = newcap;
}

static void config_set_binding(config_t *cfg, uint32_t mods, xkb_keysym_t keysym, action_t action) {
    for (int i = 0; i < cfg->count; i++) {
        if (cfg->items[i].mods == mods && cfg->items[i].keysym == keysym) {
            cfg->items[i].action = action;
            return;
        }
    }
    config_ensure_capacity(cfg);
    if (cfg->count >= cfg->capacity) return;
    cfg->items[cfg->count].mods = mods;
    cfg->items[cfg->count].keysym = keysym;
    cfg->items[cfg->count].action = action;
    cfg->count++;
}

int config_parse_mods(const char *s, uint32_t *out_mods, char **out_key) {
    if (!s || !*s || !out_mods || !out_key) return -1;
    char *copy = strdup(s);
    if (!copy) return -1;
    /* count tokens */
    int n = 0;
    /* first pass count */
    char *tmp = strdup(s);
    char *save = NULL;
    char *t = strtok_r(tmp, "+", &save);
    /* collect */
    char **toks = NULL;
    int cap = 0;
    while (t) {
        char *tt = trim(t);
        if (*tt) {
            char *alias = tt;
            if (strcmp(tt, "+") == 0) alias = "plus";
            else if (strcmp(tt, "-") == 0) alias = "minus";
            if (n == cap) {
                cap = cap ? cap * 2 : 4;
                toks = realloc(toks, cap * sizeof(char *));
            }
            toks[n++] = strdup(alias);
        }
        t = strtok_r(NULL, "+", &save);
    }
    free(tmp);
    if (n == 0) { free(copy); free(toks); return -1; }

    uint32_t mods = 0;
    for (int i = 0; i < n - 1; i++) {
        if (strcasecmp(toks[i], "ctrl") == 0 || strcasecmp(toks[i], "control") == 0) mods |= MOD_CTRL;
        else if (strcasecmp(toks[i], "shift") == 0) mods |= MOD_SHIFT;
        else if (strcasecmp(toks[i], "alt") == 0) mods |= MOD_ALT;
        else if (strcasecmp(toks[i], "super") == 0 || strcasecmp(toks[i], "meta") == 0 || strcasecmp(toks[i], "win") == 0) mods |= MOD_SUPER;
        else {
            /* unknown modifier -> fail */
            for (int j = 0; j < n; j++) free(toks[j]);
            free(toks);
            free(copy);
            return -1;
        }
        free(toks[i]);
    }
    *out_mods = mods;
    *out_key = toks[n - 1];
    /* free remaining token strings except key (transferred) */
    for (int i = 0; i < n - 1; i++) { /* already freed */ }
    free(toks);
    free(copy);
    return 0;
}

action_t config_parse_action(const char *s) {
    if (!s) return ACTION_NONE;
    char buf[128];
    snprintf(buf, sizeof(buf), "%s", s);
    trim(buf);
    if (strcmp(buf, "quit") == 0) return ACTION_QUIT;
    if (strcmp(buf, "cancel") == 0) return ACTION_CANCEL;
    if (strcmp(buf, "rotate") == 0) return ACTION_ROTATE;
    if (strcmp(buf, "clear") == 0) return ACTION_CLEAR;
    if (strcmp(buf, "pause") == 0) return ACTION_PAUSE;
    if (strcmp(buf, "step") == 0) return ACTION_STEP;
    if (strcmp(buf, "speed_up") == 0) return ACTION_SPEED_UP;
    if (strcmp(buf, "speed_down") == 0) return ACTION_SPEED_DOWN;
    if (strcmp(buf, "toggle_grid") == 0) return ACTION_TOGGLE_GRID;
    if (strncmp(buf, "select:", 7) == 0) {
        const char *pat = buf + 7;
        if (strcmp(pat, "glider") == 0) return ACTION_SELECT_GLIDER;
        if (strcmp(pat, "blinker") == 0) return ACTION_SELECT_BLINKER;
        if (strcmp(pat, "block") == 0) return ACTION_SELECT_BLOCK;
        if (strcmp(pat, "toad") == 0) return ACTION_SELECT_TOAD;
        if (strcmp(pat, "beacon") == 0) return ACTION_SELECT_BEACON;
        if (strcmp(pat, "boat") == 0) return ACTION_SELECT_BOAT;
        if (strcmp(pat, "tub") == 0) return ACTION_SELECT_TUB;
        if (strcmp(pat, "beehive") == 0) return ACTION_SELECT_BEEHIVE;
        if (strcmp(pat, "rpentomino") == 0) return ACTION_SELECT_RPENTOMINO;
        if (strcmp(pat, "acorn") == 0) return ACTION_SELECT_ACORN;
    }
    return ACTION_NONE;
}

config_t config_defaults(void) {
    config_t cfg = {0};
    struct { const char *key; action_t action; } defs[] = {
        {"1", ACTION_SELECT_GLIDER},
        {"2", ACTION_SELECT_BLINKER},
        {"3", ACTION_SELECT_BLOCK},
        {"4", ACTION_SELECT_TOAD},
        {"5", ACTION_SELECT_BEACON},
        {"6", ACTION_SELECT_BOAT},
        {"7", ACTION_SELECT_TUB},
        {"8", ACTION_SELECT_BEEHIVE},
        {"9", ACTION_SELECT_RPENTOMINO},
        {"0", ACTION_SELECT_ACORN},
        {"space", ACTION_ROTATE},
        {"escape", ACTION_CANCEL},
        {"ctrl+q", ACTION_QUIT},
        {"p", ACTION_PAUSE},
        {"n", ACTION_STEP},
        {"+", ACTION_SPEED_UP},
        {"-", ACTION_SPEED_DOWN},
    };
    int ndef = sizeof(defs) / sizeof(defs[0]);
    for (int i = 0; i < ndef; i++) {
        uint32_t mods = 0;
        char *key = NULL;
        if (config_parse_mods(defs[i].key, &mods, &key) != 0) continue;
        xkb_keysym_t sym = xkb_keysym_from_name(key, XKB_KEYSYM_CASE_INSENSITIVE);
        free(key);
        if (sym == XKB_KEY_NoSymbol) continue;
        config_set_binding(&cfg, mods, sym, defs[i].action);
    }
    return cfg;
}

static const char *default_file_content =
    "# wlgol key bindings\n"
    "[bindings]\n"
    "\"1\" = \"select:glider\"\n"
    "\"2\" = \"select:blinker\"\n"
    "\"3\" = \"select:block\"\n"
    "\"4\" = \"select:toad\"\n"
    "\"5\" = \"select:beacon\"\n"
    "\"6\" = \"select:boat\"\n"
    "\"7\" = \"select:tub\"\n"
    "\"8\" = \"select:beehive\"\n"
    "\"9\" = \"select:rpentomino\"\n"
    "\"0\" = \"select:acorn\"\n"
    "\"space\" = \"rotate\"\n"
    "\"escape\" = \"cancel\"\n"
    "\"ctrl+q\" = \"quit\"\n"
    "\"p\" = \"pause\"\n"
    "\"n\" = \"step\"\n"
    "\"+\" = \"speed_up\"\n"
    "\"-\" = \"speed_down\"\n";

int config_ensure_default_file(const char *path) {
    if (!path) return -1;
    struct stat st;
    if (stat(path, &st) == 0) return 0;
    char *parent = strdup(path);
    char *grand = strdup(path);
    dirname(parent);
    /* parent of parent */
    char *p2 = strdup(parent);
    dirname(p2);
    mkdir(p2, 0755);
    mkdir(parent, 0755);
    free(p2);

    FILE *fp = fopen(path, "w");
    if (!fp) { free(parent); free(grand); return -1; }
    fputs(default_file_content, fp);
    fclose(fp);
    free(parent);
    free(grand);
    return 0;
}

config_t config_load(const char *path) {
    config_t cfg = config_defaults();
    config_ensure_default_file(path);
    FILE *fp = fopen(path, "r");
    if (!fp) return cfg;
    char errbuf[512];
    toml_table_t *tab = toml_parse_file(fp, errbuf, sizeof(errbuf));
    fclose(fp);
    if (!tab) return cfg;
    toml_table_t *bindings = toml_table_in(tab, "bindings");
    if (bindings) {
        int n = toml_table_nkval(bindings);
        for (int i = 0; i < n; i++) {
            const char *keystr = toml_key_in(bindings, i);
            if (!keystr) break;
            toml_datum_t d = toml_string_in(bindings, keystr);
            if (!d.ok) { if (d.u.s) free(d.u.s); continue; }
            uint32_t mods = 0;
            char *key = NULL;
            if (config_parse_mods(keystr, &mods, &key) != 0) { free(d.u.s); continue; }
            xkb_keysym_t sym = xkb_keysym_from_name(key, XKB_KEYSYM_CASE_INSENSITIVE);
            free(key);
            if (sym == XKB_KEY_NoSymbol) { free(d.u.s); continue; }
            action_t act = config_parse_action(d.u.s);
            free(d.u.s);
            if (act == ACTION_NONE) continue;
            config_set_binding(&cfg, mods, sym, act);
        }
    }
    toml_free(tab);
    return cfg;
}

void config_free(config_t *cfg) {
    if (!cfg) return;
    free(cfg->items);
    cfg->items = NULL;
    cfg->count = 0;
    cfg->capacity = 0;
}

action_t config_lookup(const config_t *cfg, uint32_t mods, xkb_keysym_t keysym) {
    if (!cfg) return ACTION_NONE;
    for (int i = 0; i < cfg->count; i++) {
        if (cfg->items[i].mods == mods && cfg->items[i].keysym == keysym) {
            return cfg->items[i].action;
        }
    }
    return ACTION_NONE;
}