#include "frankenphp.h"
#include <SAPI.h>
#include <Zend/zend_alloc.h>
#include <Zend/zend_exceptions.h>
#include <Zend/zend_interfaces.h>
#include <errno.h>
#include <ext/spl/spl_exceptions.h>
#include <ext/standard/head.h>
#ifdef HAVE_PHP_SESSION
#include <ext/session/php_session.h>
#endif
#include <inttypes.h>
#include <php.h>
#ifdef PHP_WIN32
#include <config.w32.h>
#else
#include <php_config.h>
#endif
#include <php_ini.h>
#include <php_main.h>
#include <php_output.h>
#include <php_variables.h>
#include <php_version.h>
#include <pthread.h>
#include <sapi/embed/php_embed.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#ifndef ZEND_WIN32
#include <unistd.h>
#endif
#if defined(__linux__)
#include <sys/prctl.h>
#elif defined(__FreeBSD__) || defined(__OpenBSD__)
#include <pthread_np.h>
#endif

#if PHP_VERSION_ID >= 80600
#include <sapi/cli/cli.h>
#else
#include "emulate_php_cli.h"
#endif

#include "_cgo_export.h"
#include "frankenphp_arginfo.h"

#if defined(PHP_WIN32) && defined(ZTS)
ZEND_TSRMLS_CACHE_DEFINE()
#endif

/**
 * The list of modules to reload on each request. If an external module
 * requires to be reloaded between requests, it is possible to hook on
 * `sapi_module.activate` and `sapi_module.deactivate`.
 *
 * @see https://github.com/DataDog/dd-trace-php/pull/3169 for an example
 */
static const char *MODULES_TO_RELOAD[] = {"filter", NULL};

frankenphp_version frankenphp_get_version() {
  return (frankenphp_version){
      PHP_MAJOR_VERSION, PHP_MINOR_VERSION, PHP_RELEASE_VERSION,
      PHP_EXTRA_VERSION, PHP_VERSION,       PHP_VERSION_ID,
  };
}

frankenphp_config frankenphp_get_config() {
  return (frankenphp_config){
#ifdef ZTS
      true,
#else
      false,
#endif
#ifdef ZEND_SIGNALS
      true,
#else
      false,
#endif
#ifdef ZEND_MAX_EXECUTION_TIMERS
      true,
#else
      false,
#endif
  };
}

bool should_filter_var = 0;
bool original_user_abort_setting = 0;
frankenphp_interned_strings_t frankenphp_strings = {0};
HashTable *main_thread_env = NULL;

__thread uintptr_t thread_index;
__thread bool is_worker_thread = false;
__thread HashTable *sandboxed_env = NULL;

void frankenphp_update_local_thread_context(bool is_worker) {
  is_worker_thread = is_worker;

  /* workers should keep running if the user aborts the connection */
  PG(ignore_user_abort) = is_worker ? 1 : original_user_abort_setting;
}

static void frankenphp_update_request_context() {
  /* the server context is stored on the go side, still SG(server_context) needs
   * to not be NULL */
  SG(server_context) = (void *)1;
  /* status It is not reset by zend engine, set it to 200. */
  SG(sapi_headers).http_response_code = 200;

  char *authorization_header =
      go_update_request_info(thread_index, &SG(request_info));

  /* let PHP handle basic auth */
  php_handle_auth_data(authorization_header);
}

static void frankenphp_free_request_context() {
  if (SG(request_info).cookie_data != NULL) {
    free(SG(request_info).cookie_data);
    SG(request_info).cookie_data = NULL;
  }

  /* freed via thread.Unpin() */
  SG(request_info).request_method = NULL;
  SG(request_info).query_string = NULL;
  SG(request_info).content_type = NULL;
  SG(request_info).path_translated = NULL;
  SG(request_info).request_uri = NULL;
}

/* reset all 'auto globals' in worker mode except of $_ENV
 * see: php_hash_environment() */
static void frankenphp_reset_super_globals() {
  zend_try {
    /* only $_FILES needs to be flushed explicitly
     * $_GET, $_POST, $_COOKIE and $_SERVER are flushed on reimport
     * $_ENV is not flushed
     * for more info see: php_startup_auto_globals()
     */
    zval *files = &PG(http_globals)[TRACK_VARS_FILES];
    zval_ptr_dtor_nogc(files);
    memset(files, 0, sizeof(*files));

    /* $_SESSION must be explicitly deleted from the symbol table.
     * Unlike other superglobals, $_SESSION is stored in EG(symbol_table)
     * with a reference to PS(http_session_vars). The session RSHUTDOWN
     * only decrements the refcount but doesn't remove it from the symbol
     * table, causing data to leak between requests. */
    zend_hash_str_del(&EG(symbol_table), "_SESSION", sizeof("_SESSION") - 1);
  }
  zend_end_try();

  zend_auto_global *auto_global;
  zend_string *_env = ZSTR_KNOWN(ZEND_STR_AUTOGLOBAL_ENV);
  zend_string *_server = ZSTR_KNOWN(ZEND_STR_AUTOGLOBAL_SERVER);
  ZEND_HASH_MAP_FOREACH_PTR(CG(auto_globals), auto_global) {
    if (auto_global->name == _env) {
      /* skip $_ENV */
    } else if (auto_global->name == _server) {
      /* always reimport $_SERVER */
      auto_global->armed = auto_global->auto_global_callback(auto_global->name);
    } else if (auto_global->jit) {
      /* JIT globals ($_REQUEST, $GLOBALS) need special handling:
       * - $GLOBALS will always be handled by the application, we skip it
       * For $_REQUEST:
       * - If in symbol_table: re-initialize with current request data
       * - If not: do nothing, it may be armed by jit later */
      if (auto_global->name == ZSTR_KNOWN(ZEND_STR_AUTOGLOBAL_REQUEST) &&
          zend_hash_exists(&EG(symbol_table), auto_global->name)) {
        auto_global->armed =
            auto_global->auto_global_callback(auto_global->name);
      }
    } else if (auto_global->auto_global_callback) {
      /* $_GET, $_POST, $_COOKIE, $_FILES are reimported here */
      auto_global->armed = auto_global->auto_global_callback(auto_global->name);
    } else {
      /* $_SESSION will land here (not an http_global) */
      auto_global->armed = 0;
    }
  }
  ZEND_HASH_FOREACH_END();
}

/*
 * free php_stream resources that are temporary (php_stream_temp_ops)
 * streams are globally registered in EG(regular_list), see zend_list.c
 * this fixes a leak when reading the body of a request
 */
static void frankenphp_release_temporary_streams() {
  zend_resource *val;
  int stream_type = php_file_le_stream();
  ZEND_HASH_FOREACH_PTR(&EG(regular_list), val) {
    /* verify the resource is a stream */
    if (val->type == stream_type) {
      php_stream *stream = (php_stream *)val->ptr;
      if (stream != NULL && stream->ops == &php_stream_temp_ops &&
          stream->__exposed == 0 && GC_REFCOUNT(val) == 1) {
        ZEND_ASSERT(!stream->is_persistent);
        zend_list_delete(val);
      }
    }
  }
  ZEND_HASH_FOREACH_END();
}

#ifdef HAVE_PHP_SESSION
/* Reset session state between worker requests, preserving user handlers.
 * Based on php_rshutdown_session_globals() + php_rinit_session_globals(). */
static void frankenphp_reset_session_state(void) {
  if (PS(session_status) == php_session_active) {
    php_session_flush(1);
  }

  if (!Z_ISUNDEF(PS(http_session_vars))) {
    zval_ptr_dtor(&PS(http_session_vars));
    ZVAL_UNDEF(&PS(http_session_vars));
  }

  if (PS(mod_data) || PS(mod_user_implemented)) {
    zend_try { PS(mod)->s_close(&PS(mod_data)); }
    zend_end_try();
  }

  if (PS(id)) {
    zend_string_release_ex(PS(id), 0);
    PS(id) = NULL;
  }

  if (PS(session_vars)) {
    zend_string_release_ex(PS(session_vars), 0);
    PS(session_vars) = NULL;
  }

  /* PS(mod_user_class_name) and PS(mod_user_names) are preserved */

#if PHP_VERSION_ID >= 80300
  if (PS(session_started_filename)) {
    zend_string_release(PS(session_started_filename));
    PS(session_started_filename) = NULL;
    PS(session_started_lineno) = 0;
  }
#endif

  PS(session_status) = php_session_none;
  PS(in_save_handler) = 0;
  PS(set_handler) = 0;
  PS(mod_data) = NULL;
  PS(mod_user_is_open) = 0;
  PS(define_sid) = 1;
}
#endif

/* Adapted from php_request_shutdown */
static void frankenphp_worker_request_shutdown() {
  /* Flush all output buffers */
  zend_try { php_output_end_all(); }
  zend_end_try();

  const char **module_name;
  zend_module_entry *module;
  for (module_name = MODULES_TO_RELOAD; *module_name; module_name++) {
    if ((module = zend_hash_str_find_ptr(&module_registry, *module_name,
                                         strlen(*module_name)))) {
      module->request_shutdown_func(module->type, module->module_number);
    }
  }

#ifdef HAVE_PHP_SESSION
  frankenphp_reset_session_state();
#endif

  /* Shutdown output layer (send the set HTTP headers, cleanup output handlers,
   * etc.) */
  zend_try { php_output_deactivate(); }
  zend_end_try();

  /* SAPI related shutdown (free stuff) */
  zend_try { sapi_deactivate(); }
  zend_end_try();
  frankenphp_free_request_context();

  zend_set_memory_limit(PG(memory_limit));
}

// shutdown the dummy request that starts the worker script
bool frankenphp_shutdown_dummy_request(void) {
  if (SG(server_context) == NULL) {
    return false;
  }

  frankenphp_worker_request_shutdown();

  return true;
}

void get_full_env(zval *track_vars_array) {
  zend_hash_copy(Z_ARR_P(track_vars_array), main_thread_env, NULL);
}

/* Adapted from php_request_startup() */
static int frankenphp_worker_request_startup() {
  int retval = SUCCESS;

  frankenphp_update_request_context();

  zend_try {
    frankenphp_release_temporary_streams();
    php_output_activate();

    /* initialize global variables */
    PG(header_is_being_sent) = 0;
    PG(connection_status) = PHP_CONNECTION_NORMAL;

    /* Keep the current execution context */
    sapi_activate();

#ifdef ZEND_MAX_EXECUTION_TIMERS
    if (PG(max_input_time) == -1) {
      zend_set_timeout(EG(timeout_seconds), 1);
    } else {
      zend_set_timeout(PG(max_input_time), 1);
    }
#endif

    if (PG(expose_php)) {
      sapi_add_header(SAPI_PHP_VERSION_HEADER,
                      sizeof(SAPI_PHP_VERSION_HEADER) - 1, 1);
    }

    if (PG(output_handler) && PG(output_handler)[0]) {
      zval oh;

      ZVAL_STRING(&oh, PG(output_handler));
      php_output_start_user(&oh, 0, PHP_OUTPUT_HANDLER_STDFLAGS);
      zval_ptr_dtor(&oh);
    } else if (PG(output_buffering)) {
      php_output_start_user(NULL,
                            PG(output_buffering) > 1 ? PG(output_buffering) : 0,
                            PHP_OUTPUT_HANDLER_STDFLAGS);
    } else if (PG(implicit_flush)) {
      php_output_set_implicit_flush(1);
    }

    frankenphp_reset_super_globals();

    const char **module_name;
    zend_module_entry *module;
    for (module_name = MODULES_TO_RELOAD; *module_name; module_name++) {
      if ((module = zend_hash_str_find_ptr(&module_registry, *module_name,
                                           strlen(*module_name))) &&
          module->request_startup_func) {
        module->request_startup_func(module->type, module->module_number);
      }
    }
  }
  zend_catch { retval = FAILURE; }
  zend_end_try();

  SG(sapi_started) = 1;

  return retval;
}

PHP_FUNCTION(frankenphp_finish_request) { /* {{{ */
  ZEND_PARSE_PARAMETERS_NONE();

  if (go_is_context_done(thread_index)) {
    RETURN_FALSE;
  }

  php_output_end_all();
  php_header();

  go_frankenphp_finish_php_request(thread_index);

  RETURN_TRUE;
} /* }}} */

/* {{{ Call go's putenv to prevent race conditions */
PHP_FUNCTION(frankenphp_putenv) {
  char *setting;
  size_t setting_len;

  ZEND_PARSE_PARAMETERS_START(1, 1)
  Z_PARAM_STRING(setting, setting_len)
  ZEND_PARSE_PARAMETERS_END();

  // Cast str_len to int (ensure it fits in an int)
  if (setting_len > INT_MAX) {
    php_error(E_WARNING, "String length exceeds maximum integer value");
    RETURN_FALSE;
  }

  if (setting_len == 0 || setting[0] == '=') {
    zend_argument_value_error(1, "must have a valid syntax");
    RETURN_THROWS();
  }

  if (sandboxed_env == NULL) {
    sandboxed_env = zend_array_dup(main_thread_env);
  }

  /* cut at null byte to stay consistent with regular putenv */
  char *null_pos = memchr(setting, '\0', setting_len);
  if (null_pos != NULL) {
    setting_len = null_pos - setting;
  }

  /* cut the string at the first '=' */
  char *eq_pos = memchr(setting, '=', setting_len);
  bool success = true;

  /* no '=' found, delete the variable */
  if (eq_pos == NULL) {
    success = go_putenv(setting, (int)setting_len, NULL, 0);
    if (success) {
      zend_hash_str_del(sandboxed_env, setting, setting_len);
    }

    RETURN_BOOL(success);
  }

  size_t name_len = eq_pos - setting;
  size_t value_len =
      (setting_len > name_len + 1) ? (setting_len - name_len - 1) : 0;
  success = go_putenv(setting, (int)name_len, eq_pos + 1, (int)value_len);
  if (success) {
    zval val = {0};
    ZVAL_STRINGL(&val, eq_pos + 1, value_len);
    zend_hash_str_update(sandboxed_env, setting, name_len, &val);
  }

  RETURN_BOOL(success);
} /* }}} */

/* {{{ Get the env from the sandboxed environment */
PHP_FUNCTION(frankenphp_getenv) {
  zend_string *name = NULL;
  bool local_only = 0;

  ZEND_PARSE_PARAMETERS_START(0, 2)
  Z_PARAM_OPTIONAL
  Z_PARAM_STR_OR_NULL(name)
  Z_PARAM_BOOL(local_only)
  ZEND_PARSE_PARAMETERS_END();

  HashTable *ht = sandboxed_env ? sandboxed_env : main_thread_env;

  if (!name) {
    RETURN_ARR(zend_array_dup(ht));
    return;
  }

  zval *env_val = zend_hash_find(ht, name);
  if (env_val && Z_TYPE_P(env_val) == IS_STRING) {
    zend_string *str = Z_STR_P(env_val);
    zend_string_addref(str);
    RETVAL_STR(str);
  } else {
    RETVAL_FALSE;
  }
} /* }}} */

/* {{{ Fetch all HTTP request headers */
PHP_FUNCTION(frankenphp_request_headers) {
  ZEND_PARSE_PARAMETERS_NONE();

  struct go_apache_request_headers_return headers =
      go_apache_request_headers(thread_index);

  array_init_size(return_value, headers.r1);

  for (size_t i = 0; i < headers.r1; i++) {
    go_string key = headers.r0[i * 2];
    go_string val = headers.r0[i * 2 + 1];

    add_assoc_stringl_ex(return_value, key.data, key.len, val.data, val.len);
  }
}
/* }}} */

/* add_response_header and apache_response_headers are copied from
 * https://github.com/php/php-src/blob/master/sapi/cli/php_cli_server.c
 * Copyright (c) The PHP Group
 * Licensed under The PHP License
 * Original authors: Moriyoshi Koizumi <moriyoshi@php.net> and Xinchen Hui
 * <laruence@php.net>
 */
static void add_response_header(sapi_header_struct *h,
                                zval *return_value) /* {{{ */
{
  if (h->header_len > 0) {
    char *s;
    size_t len = 0;
    ALLOCA_FLAG(use_heap)

    char *p = strchr(h->header, ':');
    if (NULL != p) {
      len = p - h->header;
    }
    if (len > 0) {
      while (len != 0 &&
             (h->header[len - 1] == ' ' || h->header[len - 1] == '\t')) {
        len--;
      }
      if (len) {
        s = do_alloca(len + 1, use_heap);
        memcpy(s, h->header, len);
        s[len] = 0;
        do {
          p++;
        } while (*p == ' ' || *p == '\t');
        add_assoc_stringl_ex(return_value, s, len, p,
                             h->header_len - (p - h->header));
        free_alloca(s, use_heap);
      }
    }
  }
}
/* }}} */

PHP_FUNCTION(frankenphp_response_headers) /* {{{ */
{
  ZEND_PARSE_PARAMETERS_NONE();

  array_init(return_value);
  zend_llist_apply_with_argument(
      &SG(sapi_headers).headers,
      (llist_apply_with_arg_func_t)add_response_header, return_value);
}
/* }}} */

PHP_FUNCTION(frankenphp_handle_request) {
  zend_fcall_info fci;
  zend_fcall_info_cache fcc;

  ZEND_PARSE_PARAMETERS_START(1, 1)
  Z_PARAM_FUNC(fci, fcc)
  ZEND_PARSE_PARAMETERS_END();

  if (!is_worker_thread) {
    /* not a worker, throw an error */
    zend_throw_exception(
        spl_ce_RuntimeException,
        "frankenphp_handle_request() called while not in worker mode", 0);
    RETURN_THROWS();
  }

#ifdef ZEND_MAX_EXECUTION_TIMERS
  /* Disable timeouts while waiting for a request to handle */
  zend_unset_timeout();
#endif

  struct go_frankenphp_worker_handle_request_start_return result =
      go_frankenphp_worker_handle_request_start(thread_index);
  if (frankenphp_worker_request_startup() == FAILURE
      /* Shutting down */
      || !result.r0) {
    RETURN_FALSE;
  }

#ifdef ZEND_MAX_EXECUTION_TIMERS
  /*
   * Reset default timeout
   */
  if (PG(max_input_time) != -1) {
    zend_set_timeout(INI_INT("max_execution_time"), 0);
  }
#endif

  /* Call the PHP func passed to frankenphp_handle_request() */
  zval retval = {0};
  zval *callback_ret = NULL;

  fci.size = sizeof fci;
  fci.retval = &retval;
  fci.params = result.r1;
  fci.param_count = result.r1 == NULL ? 0 : 1;

  if (zend_call_function(&fci, &fcc) == SUCCESS && Z_TYPE(retval) != IS_UNDEF) {
    callback_ret = &retval;

    /* pass NULL instead of the NULL zval as return value */
    if (Z_TYPE(retval) == IS_NULL) {
      callback_ret = NULL;
    }
  }

  /*
   * If an exception occurred, print the message to the client before
   * closing the connection.
   */
  if (EG(exception)) {
    if (!zend_is_unwind_exit(EG(exception)) &&
        !zend_is_graceful_exit(EG(exception))) {
      zend_exception_error(EG(exception), E_ERROR);
    } else {
      /* exit() will jump directly to after php_execute_script */
      zend_bailout();
    }
  }

  frankenphp_worker_request_shutdown();
  go_frankenphp_finish_worker_request(thread_index, callback_ret);
  if (result.r1 != NULL) {
    zval_ptr_dtor(result.r1);
  }
  if (callback_ret != NULL) {
    zval_ptr_dtor(&retval);
  }

  RETURN_TRUE;
}

PHP_FUNCTION(headers_send) {
  zend_long response_code = 200;

  ZEND_PARSE_PARAMETERS_START(0, 1)
  Z_PARAM_OPTIONAL
  Z_PARAM_LONG(response_code)
  ZEND_PARSE_PARAMETERS_END();

  int previous_status_code = SG(sapi_headers).http_response_code;
  SG(sapi_headers).http_response_code = response_code;

  if (response_code >= 100 && response_code < 200) {
    int ret = sapi_module.send_headers(&SG(sapi_headers));
    SG(sapi_headers).http_response_code = previous_status_code;

    RETURN_LONG(ret);
  }

  RETURN_LONG(sapi_send_headers());
}

PHP_FUNCTION(mercure_publish) {
  zval *topics;
  zend_string *data = NULL, *id = NULL, *type = NULL;
  zend_bool private = 0;
  zend_long retry = 0;
  bool retry_is_null = 1;

  ZEND_PARSE_PARAMETERS_START(1, 6)
  Z_PARAM_ZVAL(topics)
  Z_PARAM_OPTIONAL
  Z_PARAM_STR_OR_NULL(data)
  Z_PARAM_BOOL(private)
  Z_PARAM_STR_OR_NULL(id)
  Z_PARAM_STR_OR_NULL(type)
  Z_PARAM_LONG_OR_NULL(retry, retry_is_null)
  ZEND_PARSE_PARAMETERS_END();

  if (Z_TYPE_P(topics) != IS_ARRAY && Z_TYPE_P(topics) != IS_STRING) {
    zend_argument_type_error(1, "must be of type array|string");
    RETURN_THROWS();
  }

  struct go_mercure_publish_return result =
      go_mercure_publish(thread_index, topics, data, private, id, type, retry);

  switch (result.r1) {
  case 0:
    RETURN_STR(result.r0);
  case 1:
    zend_throw_exception(spl_ce_RuntimeException, "No Mercure hub configured",
                         0);
    RETURN_THROWS();
  case 2:
    zend_throw_exception(spl_ce_RuntimeException, "Publish failed", 0);
    RETURN_THROWS();
  }

  zend_throw_exception(spl_ce_RuntimeException,
                       "FrankenPHP not built with Mercure support", 0);
  RETURN_THROWS();
}

PHP_FUNCTION(frankenphp_log) {
  zend_string *message = NULL;
  zend_long level = 0;
  zval *context = NULL;

  ZEND_PARSE_PARAMETERS_START(1, 3)
  Z_PARAM_STR(message)
  Z_PARAM_OPTIONAL
  Z_PARAM_LONG(level)
  Z_PARAM_ARRAY(context)
  ZEND_PARSE_PARAMETERS_END();

  char *ret = NULL;
  ret = go_log_attrs(thread_index, message, level, context);
  if (ret != NULL) {
    zend_throw_exception(spl_ce_RuntimeException, ret, 0);
    free(ret);
    RETURN_THROWS();
  }
}

PHP_MINIT_FUNCTION(frankenphp) {
  register_frankenphp_symbols(module_number);

  zend_function *func;

  // Override putenv
  func = zend_hash_str_find_ptr(CG(function_table), "putenv",
                                sizeof("putenv") - 1);
  if (func != NULL && func->type == ZEND_INTERNAL_FUNCTION) {
    ((zend_internal_function *)func)->handler = ZEND_FN(frankenphp_putenv);
  } else {
    php_error(E_WARNING, "Failed to find built-in putenv function");
  }

  // Override getenv
  func = zend_hash_str_find_ptr(CG(function_table), "getenv",
                                sizeof("getenv") - 1);
  if (func != NULL && func->type == ZEND_INTERNAL_FUNCTION) {
    ((zend_internal_function *)func)->handler = ZEND_FN(frankenphp_getenv);
  } else {
    php_error(E_WARNING, "Failed to find built-in getenv function");
  }

  return SUCCESS;
}

static zend_module_entry frankenphp_module = {
    STANDARD_MODULE_HEADER,
    "frankenphp",
    ext_functions,         /* function table */
    PHP_MINIT(frankenphp), /* initialization */
    NULL,                  /* shutdown */
    NULL,                  /* request initialization */
    NULL,                  /* request shutdown */
    NULL,                  /* information */
    TOSTRING(FRANKENPHP_VERSION),
    STANDARD_MODULE_PROPERTIES};

static int frankenphp_startup(sapi_module_struct *sapi_module) {
  php_import_environment_variables = get_full_env;

  return php_module_startup(sapi_module, &frankenphp_module);
}

static int frankenphp_deactivate(void) { return SUCCESS; }

static size_t frankenphp_ub_write(const char *str, size_t str_length) {
  struct go_ub_write_return result =
      go_ub_write(thread_index, (char *)str, str_length);

  if (result.r1) {
    php_handle_aborted_connection();
  }

  return result.r0;
}

static int frankenphp_send_headers(sapi_headers_struct *sapi_headers) {
  if (SG(request_info).no_headers == 1) {
    return SAPI_HEADER_SENT_SUCCESSFULLY;
  }

  int status;

  if (SG(sapi_headers).http_status_line) {
    status = atoi((SG(sapi_headers).http_status_line) + 9);
  } else {
    status = SG(sapi_headers).http_response_code;

    if (!status) {
      status = 200;
    }
  }

  bool success = go_write_headers(thread_index, status, &sapi_headers->headers);
  if (success) {
    return SAPI_HEADER_SENT_SUCCESSFULLY;
  }

  return SAPI_HEADER_SEND_FAILED;
}

static void frankenphp_sapi_flush(void *server_context) {
  sapi_send_headers();
  if (go_sapi_flush(thread_index)) {
    php_handle_aborted_connection();
  }
}

static size_t frankenphp_read_post(char *buffer, size_t count_bytes) {
  return go_read_post(thread_index, buffer, count_bytes);
}

static char *frankenphp_read_cookies(void) {
  return go_read_cookies(thread_index);
}

/* all variables with well defined keys can safely be registered like this */
static inline void frankenphp_register_trusted_var(zend_string *z_key,
                                                   char *value, size_t val_len,
                                                   HashTable *ht) {
  if (value == NULL) {
    zval empty;
    ZVAL_EMPTY_STRING(&empty);
    zend_hash_update_ind(ht, z_key, &empty);
    return;
  }
  size_t new_val_len = val_len;

  if (!should_filter_var ||
      sapi_module.input_filter(PARSE_SERVER, ZSTR_VAL(z_key), &value,
                               new_val_len, &new_val_len)) {
    zval z_value;
    ZVAL_STRINGL_FAST(&z_value, value, new_val_len);
    zend_hash_update_ind(ht, z_key, &z_value);
  }
}

/* Register known $_SERVER variables in bulk to avoid cgo overhead */
void frankenphp_register_server_vars(zval *track_vars_array,
                                     frankenphp_server_vars vars) {
  HashTable *ht = Z_ARRVAL_P(track_vars_array);
  zend_hash_extend(ht, vars.total_num_vars, 0);

  // update values with variable strings
#define FRANKENPHP_REGISTER_VAR(name)                                          \
  frankenphp_register_trusted_var(frankenphp_strings.name, vars.name,          \
                                  vars.name##_len, ht)

  FRANKENPHP_REGISTER_VAR(remote_addr);
  FRANKENPHP_REGISTER_VAR(remote_host);
  FRANKENPHP_REGISTER_VAR(remote_port);
  FRANKENPHP_REGISTER_VAR(document_root);
  FRANKENPHP_REGISTER_VAR(path_info);
  FRANKENPHP_REGISTER_VAR(php_self);
  FRANKENPHP_REGISTER_VAR(document_uri);
  FRANKENPHP_REGISTER_VAR(script_filename);
  FRANKENPHP_REGISTER_VAR(script_name);
  FRANKENPHP_REGISTER_VAR(ssl_cipher);
  FRANKENPHP_REGISTER_VAR(server_name);
  FRANKENPHP_REGISTER_VAR(server_port);
  FRANKENPHP_REGISTER_VAR(content_length);
  FRANKENPHP_REGISTER_VAR(server_protocol);
  FRANKENPHP_REGISTER_VAR(http_host);
  FRANKENPHP_REGISTER_VAR(request_uri);

#undef FRANKENPHP_REGISTER_VAR

  /* update values with hard-coded zend_strings */
  zval zv;
  ZVAL_STR(&zv, frankenphp_strings.cgi11);
  zend_hash_update_ind(ht, frankenphp_strings.gateway_interface, &zv);
  ZVAL_STR(&zv, frankenphp_strings.frankenphp);
  zend_hash_update_ind(ht, frankenphp_strings.server_software, &zv);
  ZVAL_STR(&zv, vars.request_scheme);
  zend_hash_update_ind(ht, frankenphp_strings.request_scheme, &zv);
  ZVAL_STR(&zv, vars.ssl_protocol);
  zend_hash_update_ind(ht, frankenphp_strings.ssl_protocol, &zv);
  ZVAL_STR(&zv, vars.https);
  zend_hash_update_ind(ht, frankenphp_strings.https, &zv);

  /* update values with always empty strings */
  ZVAL_EMPTY_STRING(&zv);
  zend_hash_update_ind(ht, frankenphp_strings.auth_type, &zv);
  zend_hash_update_ind(ht, frankenphp_strings.remote_ident, &zv);
}

/** Create an immutable zend_string that lasts for the whole process **/
zend_string *frankenphp_init_persistent_string(const char *string, size_t len) {
  /* persistent strings will be ignored by the GC at the end of a request */
  zend_string *z_string = zend_string_init(string, len, 1);
  zend_string_hash_val(z_string);

  /* interned strings will not be ref counted by the GC */
  GC_ADD_FLAGS(z_string, IS_STR_INTERNED);

  return z_string;
}

/* initialize all hard-coded zend_strings once per process */
static void frankenphp_init_interned_strings(void) {
  if (frankenphp_strings.remote_addr != NULL) {
    return; /* already initialized */
  }

#define F_INITIALIZE_FIELD(name, str)                                          \
  frankenphp_strings.name =                                                    \
      frankenphp_init_persistent_string(str, sizeof(str) - 1);

  FRANKENPHP_INTERNED_STRINGS_LIST(F_INITIALIZE_FIELD)
#undef F_INITIALIZE_FIELD
}

/* Register variables from SG(request_info) into $_SERVER */
static inline void
frankenphp_register_variable_from_request_info(zend_string *zKey, char *value,
                                               bool must_be_present,
                                               zval *track_vars_array) {
  if (value != NULL) {
    frankenphp_register_trusted_var(zKey, value, strlen(value),
                                    Z_ARRVAL_P(track_vars_array));
  } else if (must_be_present) {
    frankenphp_register_trusted_var(zKey, NULL, 0,
                                    Z_ARRVAL_P(track_vars_array));
  }
}

static void
frankenphp_register_variables_from_request_info(zval *track_vars_array) {
  frankenphp_register_variable_from_request_info(
      frankenphp_strings.content_type, (char *)SG(request_info).content_type,
      true, track_vars_array);
  frankenphp_register_variable_from_request_info(
      frankenphp_strings.path_translated,
      (char *)SG(request_info).path_translated, false, track_vars_array);
  frankenphp_register_variable_from_request_info(
      frankenphp_strings.query_string, SG(request_info).query_string, true,
      track_vars_array);
  frankenphp_register_variable_from_request_info(
      frankenphp_strings.remote_user, (char *)SG(request_info).auth_user, false,
      track_vars_array);
  frankenphp_register_variable_from_request_info(
      frankenphp_strings.request_method,
      (char *)SG(request_info).request_method, false, track_vars_array);
}

/* Only hard-coded keys may be registered this way */
void frankenphp_register_known_variable(zend_string *z_key, char *value,
                                        size_t val_len,
                                        zval *track_vars_array) {
  frankenphp_register_trusted_var(z_key, value, val_len,
                                  Z_ARRVAL_P(track_vars_array));
}

/* variables with user-defined keys must be registered safely
 * see: php_variables.c -> php_register_variable_ex (#1106) */
void frankenphp_register_variable_safe(char *key, char *val, size_t val_len,
                                       zval *track_vars_array) {
  if (key == NULL) {
    return;
  }
  if (val == NULL) {
    val = "";
  }
  size_t new_val_len = val_len;
  if (!should_filter_var ||
      sapi_module.input_filter(PARSE_SERVER, key, &val, new_val_len,
                               &new_val_len)) {
    php_register_variable_safe(key, val, new_val_len, track_vars_array);
  }
}

void register_server_variable_filtered(const char *key, char **val,
                                       size_t *val_len,
                                       zval *track_vars_array) {
  if (sapi_module.input_filter(PARSE_SERVER, key, val, *val_len, val_len)) {
    php_register_variable_safe(key, *val, *val_len, track_vars_array);
  }
}

static void frankenphp_register_variables(zval *track_vars_array) {
  /* https://www.php.net/manual/en/reserved.variables.server.php */

  /* In CGI mode, the environment is part of the $_SERVER variables.
   * $_SERVER and $_ENV should only contain values from the original
   * environment, not values added though putenv
   */
  zend_hash_copy(Z_ARR_P(track_vars_array), main_thread_env, NULL);

  /* import CGI variables from the request context in go */
  go_register_server_variables(thread_index, track_vars_array);

  /* Some variables are already present in SG(request_info) */
  frankenphp_register_variables_from_request_info(track_vars_array);
}

static void frankenphp_log_message(const char *message, int syslog_type_int) {
  go_log(thread_index, (char *)message, syslog_type_int);
}

static char *frankenphp_getenv(const char *name, size_t name_len) {
  HashTable *ht = sandboxed_env ? sandboxed_env : main_thread_env;

  zval *env_val = zend_hash_str_find(ht, name, name_len);
  if (env_val && Z_TYPE_P(env_val) == IS_STRING) {
    zend_string *str = Z_STR_P(env_val);
    return ZSTR_VAL(str);
  }

  return NULL;
}

sapi_module_struct frankenphp_sapi_module = {
    "frankenphp", /* name */
    "FrankenPHP", /* pretty name */

    frankenphp_startup,          /* startup */
    php_module_shutdown_wrapper, /* shutdown */

    NULL,                  /* activate */
    frankenphp_deactivate, /* deactivate */

    frankenphp_ub_write,   /* unbuffered write */
    frankenphp_sapi_flush, /* flush */
    NULL,                  /* get uid */
    frankenphp_getenv,     /* getenv */

    php_error, /* error handler */

    NULL,                    /* header handler */
    frankenphp_send_headers, /* send headers handler */
    NULL,                    /* send header handler */

    frankenphp_read_post,    /* read POST data */
    frankenphp_read_cookies, /* read Cookies */

    frankenphp_register_variables, /* register server variables */
    frankenphp_log_message,        /* Log message */
    NULL,                          /* Get request time */
    NULL,                          /* Child terminate */

    STANDARD_SAPI_MODULE_PROPERTIES};

/* Sets thread name for profiling and debugging.
 *
 * Adapted from https://github.com/Pithikos/C-Thread-Pool
 * Copyright: Johan Hanssen Seferidis
 * License: MIT
 */
static void set_thread_name(char *thread_name) {
#if defined(__linux__)
  /* Use prctl instead to prevent using _GNU_SOURCE flag and implicit
   * declaration */
  prctl(PR_SET_NAME, thread_name);
#elif defined(__APPLE__) && defined(__MACH__)
  pthread_setname_np(thread_name);
#elif defined(__FreeBSD__) || defined(__OpenBSD__)
  pthread_set_name_np(pthread_self(), thread_name);
#endif
}

static void *php_thread(void *arg) {
  thread_index = (uintptr_t)arg;
  char thread_name[16] = {0};
  snprintf(thread_name, 16, "php-%" PRIxPTR, thread_index);
  set_thread_name(thread_name);

#ifdef ZTS
  /* initial resource fetch */
  (void)ts_resource(0);
#ifdef PHP_WIN32
  ZEND_TSRMLS_CACHE_UPDATE();
#endif
#endif

  // loop until Go signals to stop
  char *scriptName = NULL;
  while ((scriptName = go_frankenphp_before_script_execution(thread_index))) {
    go_frankenphp_after_script_execution(thread_index,
                                         frankenphp_execute_script(scriptName));
  }

#ifdef ZTS
  ts_free_thread();
#endif

  go_frankenphp_on_thread_shutdown(thread_index);

  return NULL;
}

static void *php_main(void *arg) {
#ifndef ZEND_WIN32
  /*
   * SIGPIPE must be masked in non-Go threads:
   * https://pkg.go.dev/os/signal#hdr-Go_programs_that_use_cgo_or_SWIG
   */
  sigset_t set;
  sigemptyset(&set);
  sigaddset(&set, SIGPIPE);

  if (pthread_sigmask(SIG_BLOCK, &set, NULL) != 0) {
    perror("failed to block SIGPIPE");
    exit(EXIT_FAILURE);
  }
#endif

  set_thread_name("php-main");

#ifdef ZTS
#if (PHP_VERSION_ID >= 80300)
  php_tsrm_startup_ex((intptr_t)arg);
#else
  php_tsrm_startup();
#endif
/*tsrm_error_set(TSRM_ERROR_LEVEL_INFO, NULL);*/
#ifdef PHP_WIN32
  ZEND_TSRMLS_CACHE_UPDATE();
#endif
#endif

  sapi_startup(&frankenphp_sapi_module);

  /* TODO: adapted from https://github.com/php/php-src/pull/16958, remove when
   * merged. */
#ifdef PHP_WIN32
  {
    const DWORD flags = GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
                        GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT;
    HMODULE module;
    /* Use a larger buffer to support long module paths on Windows. */
    wchar_t filename[32768];
    if (GetModuleHandleExW(flags, (LPCWSTR)&frankenphp_sapi_module, &module)) {
      const DWORD filename_capacity = (DWORD)_countof(filename);
      DWORD len = GetModuleFileNameW(module, filename, filename_capacity);
      if (len > 0 && len < filename_capacity) {
        wchar_t *slash = wcsrchr(filename, L'\\');
        if (slash) {
          *slash = L'\0';
          if (!SetDllDirectoryW(filename)) {
            fprintf(stderr, "Warning: SetDllDirectoryW failed (error %lu)\n",
                    GetLastError());
          }
        }
      }
    }
  }
#endif

#ifdef ZEND_MAX_EXECUTION_TIMERS
  /* overwrite php.ini with custom user settings */
  char *php_ini_overrides = go_get_custom_php_ini(false);
#else
  /* overwrite php.ini with custom user settings and disable
   * max_execution_timers */
  char *php_ini_overrides = go_get_custom_php_ini(true);
#endif

  if (php_ini_overrides != NULL) {
    frankenphp_sapi_module.ini_entries = php_ini_overrides;
  }

  frankenphp_init_interned_strings();

  frankenphp_sapi_module.startup(&frankenphp_sapi_module);

  /* check if a default filter is set in php.ini and only filter if
   * it is, this is deprecated and will be removed in PHP 9 */
  char *default_filter;
  cfg_get_string("filter.default", &default_filter);
  should_filter_var = default_filter != NULL;
  original_user_abort_setting = PG(ignore_user_abort);

  /* take a snapshot of the environment for sandboxing */
  if (main_thread_env == NULL) {
    main_thread_env = pemalloc(sizeof(HashTable), 1);
    zend_hash_init(main_thread_env, 8, NULL, NULL, 1);
    go_init_os_env(main_thread_env);
  }

  go_frankenphp_main_thread_is_ready();

  /* channel closed, shutdown gracefully */
  frankenphp_sapi_module.shutdown(&frankenphp_sapi_module);

  sapi_shutdown();
#ifdef ZTS
  tsrm_shutdown();
#endif

  if (frankenphp_sapi_module.ini_entries) {
    free((char *)frankenphp_sapi_module.ini_entries);
    frankenphp_sapi_module.ini_entries = NULL;
  }

  go_frankenphp_shutdown_main_thread();

  return NULL;
}

int frankenphp_new_main_thread(int num_threads) {
  pthread_t thread;

  if (pthread_create(&thread, NULL, &php_main, (void *)(intptr_t)num_threads) !=
      0) {
    return -1;
  }

  return pthread_detach(thread);
}

bool frankenphp_new_php_thread(uintptr_t thread_index) {
  pthread_t thread;
  if (pthread_create(&thread, NULL, &php_thread, (void *)thread_index) != 0) {
    return false;
  }
  pthread_detach(thread);
  return true;
}

static int frankenphp_request_startup() {
  frankenphp_update_request_context();
  if (php_request_startup() == SUCCESS) {
    return SUCCESS;
  }

  php_request_shutdown((void *)0);
  frankenphp_free_request_context();

  return FAILURE;
}

int frankenphp_execute_script(char *file_name) {
  if (frankenphp_request_startup() == FAILURE) {

    return FAILURE;
  }

  int status = SUCCESS;

  zend_file_handle file_handle;
  zend_stream_init_filename(&file_handle, file_name);

  file_handle.primary_script = 1;

  zend_first_try {
    EG(exit_status) = 0;
    php_execute_script(&file_handle);
    status = EG(exit_status);
  }
  zend_catch { status = EG(exit_status); }
  zend_end_try();

  zend_destroy_file_handle(&file_handle);

  /* Reset the sandboxed environment */
  if (sandboxed_env != NULL) {
    zend_hash_release(sandboxed_env);
    sandboxed_env = NULL;
  }

  php_request_shutdown((void *)0);
  frankenphp_free_request_context();

  return status;
}

typedef struct {
  char *script;
  int argc;
  char **argv;
  bool eval;
} cli_exec_args_t;

static void *execute_script_cli(void *arg) {
  cli_exec_args_t *args = (cli_exec_args_t *)arg;
  volatile int v = PHP_VERSION_ID;
  (void)v;

#if PHP_VERSION_ID >= 80600
  return (void *)(intptr_t)do_php_cli(args->argc, args->argv);
#else
  return (void *)(intptr_t)emulate_script_cli(args);
#endif
}

int frankenphp_execute_script_cli(char *script, int argc, char **argv,
                                  bool eval) {
  pthread_t thread;
  int err;
  void *exit_status;

  cli_exec_args_t args = {
      .script = script, .argc = argc, .argv = argv, .eval = eval};

  /*
   * Start the script in a dedicated thread to prevent conflicts between Go and
   * PHP signal handlers
   */
  err = pthread_create(&thread, NULL, execute_script_cli, &args);
  if (err != 0) {
    return err;
  }

  err = pthread_join(thread, &exit_status);
  if (err != 0) {
    return err;
  }

  return (intptr_t)exit_status;
}

int frankenphp_reset_opcache(void) {
  zend_function *opcache_reset =
      zend_hash_str_find_ptr(CG(function_table), ZEND_STRL("opcache_reset"));
  if (opcache_reset) {
    zend_call_known_function(opcache_reset, NULL, NULL, NULL, 0, NULL, NULL);
  }

  return 0;
}

int frankenphp_get_current_memory_limit() { return PG(memory_limit); }

static zend_module_entry **modules = NULL;
static int modules_len = 0;
static int (*original_php_register_internal_extensions_func)(void) = NULL;

int register_internal_extensions(void) {
  if (original_php_register_internal_extensions_func != NULL &&
      original_php_register_internal_extensions_func() != SUCCESS) {
    return FAILURE;
  }

  for (int i = 0; i < modules_len; i++) {
    if (zend_register_internal_module(modules[i]) == NULL) {
      return FAILURE;
    }
  }

  modules = NULL;
  modules_len = 0;

  return SUCCESS;
}

void register_extensions(zend_module_entry **m, int len) {
  modules = m;
  modules_len = len;

  original_php_register_internal_extensions_func =
      php_register_internal_extensions_func;
  php_register_internal_extensions_func = register_internal_extensions;
}