#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <assert.h>
#include "common.h"
#include "../lib/3rdparty/tinydir.h"

static struct client client = {
    .filter_mode = BM_FILTER_MODE_DMENU,
    .title = "bemenu-run",
};

struct paths {
   char *path;
   char *paths;
};

static char*
c_strdup2(const char *str, size_t size)
{
    char *cpy = calloc(1, size + 1);
    return (cpy ? memcpy(cpy, str, size) : NULL);
}

static char*
c_strdup(const char *str)
{
    return c_strdup2(str, strlen(str));
}

static char*
strip_slash(char *str)
{
    size_t size = strlen(str);
    if (size > 0)
        for (char *s = str + size - 1; *s == '/'; --s)
            *s = 0;
    return str;
}

static const char*
get_paths(const char *env, const char *default_paths, struct paths *state)
{
    if (state->path && !*state->path) {
        free(state->paths);
        return NULL;
    }

    if (!state->paths) {
        const char *paths;
        if (!(paths = getenv(env)) || !paths[0])
            paths = default_paths;

        state->path = state->paths = c_strdup(paths);
    }

    if (!state->path || !state->paths)
        return NULL;

    char *path;
    do {
        size_t f;
        path = state->path;
        if ((f = strcspn(state->path, ":")) > 0) {
            state->path += f + (path[f] ? 1 : 0);
            path[f] = 0;
        } else {
            state->path += 1;
        }

        if (!*path) {
            free(state->paths);
            return NULL;
        }
    } while (path[0] != '/');

    return strip_slash(path);
}

static int
compare(const void *a, const void *b)
{
    const struct bm_item *ia = *(struct bm_item**)a, *ib = *(struct bm_item**)b;
    return strcmp(bm_item_get_text(ia), bm_item_get_text(ib));
}

static void
read_items_to_menu_from_dir(struct bm_menu *menu, const char *path)
{
    assert(menu && path);

    tinydir_dir dir;
    if (tinydir_open(&dir, path) == -1)
        return;

    while (dir.has_next) {
        tinydir_file file;
        memset(&file, 0, sizeof(file));
        tinydir_readfile(&dir, &file);

        if (!file.is_dir && file.name) {
            struct bm_item *item;
            if (!(item = bm_item_new(file.name)))
                break;

            bm_menu_add_item(menu, item);
        }

        tinydir_next(&dir);
    }

    tinydir_close(&dir);

    uint32_t count;
    struct bm_item **items = bm_menu_get_items(menu, &count);
    qsort(items, count, sizeof(struct bm_item*), compare);

    bool unique = true;
    for (uint32_t i = 0; i + 1 < count; i += unique) {
        if (!(unique = strcmp(bm_item_get_text(items[i]), bm_item_get_text(items[i + 1])))) {
            bm_item_free(items[i]);
            bm_menu_remove_item_at(menu, i);
            items = bm_menu_get_items(menu, &count);
        }
    }
}

static void
read_items_to_menu_from_path(struct bm_menu *menu)
{
    assert(menu);

    const char *path;
    struct paths state;
    memset(&state, 0, sizeof(state));
    while ((path = get_paths("PATH", "/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:/bin:/sbin", &state)))
        read_items_to_menu_from_dir(menu, path);
}

#define WHITESPACE " \t\n\r"

static const char*
tokenize(const char *cstr, size_t *out_len, const char *separator, bool skip_whitespace, const char **state)
{
   assert(out_len && separator && state);
   const char *current = (state && *state ? *state : cstr);

   if (!current || !*current || !cstr || !*cstr)
      return NULL;

   current += strspn(current, separator);

   if (skip_whitespace)
      current += strspn(current, WHITESPACE);

   *out_len = strcspn(current, separator);
   *state = current + *out_len;

   if (skip_whitespace) {
      const size_t ws = strcspn(current, WHITESPACE);
      *out_len -= (ws < *out_len ? *out_len - ws : 0);
   }

   return current;
}

static const char*
tokenize_quoted(const char *cstr, size_t *out_len, const char *separator, const char *quotes, const char **state)
{
    assert(out_len && separator && quotes && state);
    const char *e, *current = tokenize(cstr, out_len, separator, true, state);

    if (!current)
        return NULL;

    for (const char *q = quotes; *q; ++q) {
        if (*current != *q)
            continue;

        bool escaped = false;
        for (e = ++current; *e; ++e) {
            if (escaped)
                escaped = false;
            else if (*e == '\\')
                escaped = true;
            else if (*e == *q)
                break;
        }

        *out_len = e - current;
        e = (!*e ? e : e + 1);

        if (*e) {
            size_t tmp;
            const char *state2 = NULL;
            *state = tokenize(e, &tmp, separator, true, &state2);
        } else {
            *state = e;
        }

        break;
    }

    return current;
}

static void
launch(const char *bin)
{
    if (!bin)
        return;

    if (fork() == 0) {
        setsid();
        freopen("/dev/null", "w", stdout);
        freopen("/dev/null", "w", stderr);

        size_t count = 0;
        {
            size_t len;
            const char *state = NULL;
            while (tokenize_quoted(bin, &len, " ", "\"'", &state))
                ++count;
        }

        char **tokens;
        if (!count || !(tokens = calloc(count + 1, sizeof(char*))))
            _exit(EXIT_FAILURE);

        {
            size_t i = 0, len;
            const char *t, *state = NULL;
            while (i < count && (t = tokenize_quoted(bin, &len, " ", "\"'", &state))) {
                if (!(tokens[i++] = c_strdup2(t, len)))
                    _exit(EXIT_FAILURE);
            }
        }

        execvp(tokens[0], tokens);
        _exit(EXIT_SUCCESS);
    }
}

static void
item_cb(struct bm_item *item, const char *text)
{
    (void)item; // may be null
    launch(text);
}

int
main(int argc, char **argv)
{
    struct sigaction action = {
        .sa_handler = SIG_DFL,
        .sa_flags = SA_NOCLDWAIT
    };

    // do not care about childs
    sigaction(SIGCHLD, &action, NULL);

    if (!bm_init())
        return EXIT_FAILURE;

    parse_args(&client, &argc, &argv);

    struct bm_menu *menu;
    if (!(menu = menu_with_options(&client)))
        return EXIT_FAILURE;

    read_items_to_menu_from_path(menu);
    const enum bm_run_result status = run_menu(&client, menu, item_cb);
    bm_menu_free(menu);
    return (status == BM_RUN_RESULT_SELECTED ? EXIT_SUCCESS : EXIT_FAILURE);
}

/* vim: set ts=8 sw=4 tw=0 :*/