/**
 * Copyright (c) 2025 Dominic Masters
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#pragma once
#include "script/scriptcontext.h"
#include "debug/debug.h"
#include "assert/assert.h"
#include "util/string.h"
#include "script/scriptmodule.h"

int moduleSysPrint(lua_State *L) {
  assertNotNull(L, "Lua state cannot be NULL");

  int n = lua_gettop(L);
  luaL_Buffer b;
  luaL_buffinit(L, &b);

  for (int i = 1; i <= n; ++i) {
    size_t len;
    const char *s = luaL_tolstring(L, i, &len); // converts any value to string
    luaL_addlstring(&b, s, len);
    lua_pop(L, 1); // pop result of luaL_tolstring
    if (i < n) luaL_addlstring(&b, "\t", 1);
  }

  luaL_pushresult(&b);
  const char *msg = lua_tostring(L, -1);
  debugPrint("%s\n", msg);
  return 0; // no values returned to Lua
}

int moduleSysInclude(lua_State *L) {
  assertNotNull(L, "Lua state cannot be NULL");
  
  if(!lua_isstring(L, 1)) {
    luaL_error(L, "Expected string filename");
    return 0;
  }

  scriptcontext_t* ctx = *(scriptcontext_t**)lua_getextraspace(L);
  if(ctx == NULL) {
    luaL_error(L, "Script context is NULL");
    return 0;
  }  

  const char_t *filename = luaL_checkstring(L, 1);
  if(filename == NULL || filename[0] == '\0') {
    luaL_error(L, "Filename cannot be NULL");
    return 0;
  }

  // Copy out filename to mutable buffer
  char_t buffer[1024];
  stringCopy(buffer, filename, 1024);

  // Ensure it has .dsf extension
  size_t len = strlen(buffer);
  if(len < 4 || strcmp(&buffer[len - 4], ".dsf") != 0) {
    // Append .dsf
    if(len + 4 >= 1024) {
      luaL_error(L, "Filename too long to append .dsf");
      return 0;
    }
    stringCopy(&buffer[len], ".dsf", 5);
  }

  // Execute the script file
  errorret_t err = scriptContextExecFile(
    ctx,
    buffer
  );
  if(err.code != ERROR_OK) {
    luaL_error(L, "Failed to include script file");
    errorCatch(errorPrint(err));
    return 0;
  }

  return 0;
}

int moduleSysModule(lua_State *L) {
  assertNotNull(L, "Lua state cannot be NULL");
  
  if(!lua_isstring(L, 1)) {
    luaL_error(L, "Expected string module name");
    return 0;
  }

  const char_t *moduleName = luaL_checkstring(L, 1);
  if(moduleName == NULL) {
    luaL_error(L, "Module name cannot be NULL");
    return 0;
  }

  const scriptmodule_t *module = scriptModuleGetByName(moduleName);
  if(module == NULL) {
    luaL_error(L, "Module '%s' not found", moduleName);
    return 0;
  }

  scriptcontext_t* ctx = *(scriptcontext_t**)lua_getextraspace(L);
  if(ctx == NULL) {
    luaL_error(L, "Script context is NULL");
    return 0;
  }

  module->callback(ctx);

  return 0;
}

void moduleSystem(scriptcontext_t *context) {
  assertNotNull(context, "Script context cannot be NULL");

  scriptContextRegFunc(context, "print", moduleSysPrint);
  scriptContextRegFunc(context, "include", moduleSysInclude);
  scriptContextRegFunc(context, "module", moduleSysModule);
}