/*
 
  pow! - the pow!erful package manager

  Copyright (C) 2026 forever2k38
  
  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program. If not, see <https://www.gnu.org/licenses/>.

*/

#include "package.h"

#include "lauxlib.h"
#include "lualib.h"
#include "malloc.h"
#include "pow_lua.h"
#include "stdio.h"
#include "string.h"
#include "log.h"
#include <lua.h>

int pow_extract_package_info(lua_State *L, pow_package *pkg) {
  lua_getfield(L, -1, "name");

  if (!lua_isstring(L, -1)) {
    pow_log_error("invalid package, name is not string (or doesn't exist)");

    return 1;
  }

  pkg->name = strdup(lua_tostring(L, -1));

  if (!pkg->name) {
    pow_log_error("strdup failed trying to get package name");

    return 1;
  }

  lua_pop(L, 1);

  lua_getfield(L, -1, "version");

  if (!lua_isstring(L, -1)) {
    free(pkg->name);

    pow_log_error("invalid package, version is not string (or doesn't exist)");

    return 1;
  }

  pkg->version = strdup(lua_tostring(L, -1));

  lua_pop(L, 1);

  if (!pkg->version) {
    free(pkg->name);

    pow_log_error("strdup failed trying to get package name");

    return 1;
  }

  lua_getfield(L, -1, "sources");

  if (!lua_istable(L, -1)) {
    free(pkg->name);
    free(pkg->version);

    pow_log_error("sources is not table or doesn't exist");

    return 1;
  }

  size_t sources_len = lua_objlen(L, -1);

  for (size_t i = 0; i <  sources_len; i++) {
    lua_pushinteger(L, i + 1);

    lua_gettable(L, -2);

    if (lua_type(L, -1) == LUA_TNIL)
      break;

    lua_getfield(L, -1, "path");

    pow_package_source *src = malloc(sizeof(pow_package_source));

    if (!src) {
      pow_log_error("failed to malloc pow_package_source\n");

      return 1;
    }

    if (!lua_isstring(L, -1)) {
      lua_pop(L, 1);

      pow_log_error("path is not string");

      return 1;
    }

    const char *in = strdup(lua_tostring(L, -1));

    if (!in) {
      pow_log_error("failed to strdup path?");

      return 1;
    }

    src->in = in;

    lua_pop(L, 1);

    lua_getfield(L, -1, "out");

    if (!lua_isstring(L, -1)) {
      lua_pop(L, 1);

      pow_log_error("out is not string");

      return 1;
    }

    const char *out = strdup(lua_tostring(L, -1));

    if (!out) {
      free(in);

      lua_pop(L, 1);

      pow_log_error("out strdup failed?");

      return 1;
    }

    src->out = out;

    lua_pop(L, 1);

    lua_getfield(L, -1, "hash");

    if (!lua_isstring(L, -1)) {
      free(in);
      free(out);

      pow_log_error("hash is not string?");

      return 1;
    }

    const char *hash = strdup(lua_tostring(L, -1));

    if (!hash) {
      free(in);
      free(out);

      pow_log_error("failed to strdup hash");

      return 1;
    }

    src->hash = hash;

    pkg->source_count++;

    pkg->sources =
        realloc(pkg->sources, pkg->source_count * sizeof(pow_package_source *));

    pkg->sources[pkg->source_count - 1] = src;

    lua_pop(L, 1);
  }

  lua_pop(L, 1);
  lua_pop(L, 1);
  
  return 0;
}

int pow_package_open(pow_package *pkg, pow_config *cfg, const char *path) {
  FILE *fp;
  int c;
  int err;

  fp = fopen(path, "r");

  if (!fp) {
    pow_log_error("error opening package definition, doesn't exist?");

    return 1;
  }

  char *package_buffer = malloc(4096);

  size_t total = 0;
  size_t capacity = 4096;

  while ((c = fgetc(fp)) != EOF) {
    if (total + 1 >= capacity) {
      capacity *= 2;

      char *tmp = realloc(package_buffer, capacity);

      if (!tmp) {
        fclose(fp);
        free(package_buffer);

        pow_log_error("failed to realloc package buffer");

        return 1;
      }

      pow_log_info("reallocated package buffer due to size constraints");

      package_buffer = tmp;
    }

    package_buffer[total++] = c;
  }

  fclose(fp);

  package_buffer[total] = '\0';

  lua_State *L = luaL_newstate();

  pkg->L = L;

  luaL_openlibs(L);
  pow_lua_load(L, cfg);

  luaL_loadstring(L, package_buffer);

  err = lua_pcall(L, 0, 1, 0);

  free(package_buffer);

  if (err) {
    pow_log_error("%s", lua_tostring(L, -1));

    return 1;
  }

  if (!lua_istable(L, -1)) {
    pow_log_error("invalid package, scripts must return table");

    return 1;
  }

  pkg->source_count = 0;
  pkg->sources = NULL;

  pow_extract_package_info(L, pkg);

  pkg->path = path;
  pkg->pkg_ref = luaL_ref(L, LUA_REGISTRYINDEX);

  return 0;
}

int pow_package_close(pow_package *pkg) {
  free(pkg->name);
  free(pkg->version);

  lua_close(pkg->L);

  for (size_t i = 0; i > pkg->source_count; i++) {
    pow_source_close(pkg->sources[i]);
  }

  free(pkg);

  return 0;
}