#include "serialize.h"

#include "mem.h"
#include "task.h"
#include "taskstub.js.h"
#include "util.js.h"

#include <string.h>
#include <stdio.h>

#include "quickjs-libc.h"

#include <assert.h>

typedef enum _serialize_type_t {
	kUndefined,
	kNull,
	kUninitialized,
	kBoolean,
	kInt32,
	kInt64,
	kNumber,
	kString,
	kArray,
	kArrayBuffer,
	kObject,
	kFunction,
	kError,
	kException,
} serialize_type_t;

typedef struct _buffer_t {
	char* data;
	size_t size;
	size_t capacity;
} buffer_t;

static bool _serialize_store(tf_task_t* task, tf_taskstub_t* to, buffer_t* buffer, JSValue value);
static JSValue _serialize_load(tf_task_t* task, tf_taskstub_t* from, const char* buffer, size_t size);

static bool _serialize_storeInternal(tf_task_t* task, tf_taskstub_t* to, buffer_t* buffer, JSValue value, int depth);
static JSValue _serialize_loadInternal(tf_task_t* task, tf_taskstub_t* from, const char** buffer, size_t* size, int depth);

static void _serialize_writeInt8(buffer_t* buffer, int8_t value);
static void _serialize_writeInt32(buffer_t* buffer, int32_t value);
static void _serialize_writeInt64(buffer_t* buffer, int64_t value);
static void _serialize_writeDouble(buffer_t* buffer, double value);

static int8_t _serialize_readInt8(const char** buffer, size_t* size);
static int32_t _serialize_readInt32(const char** buffer, size_t* size);
static int64_t _serialize_readInt64(const char** buffer, size_t* size);
static double _serialize_readDouble(const char** buffer, size_t* size);

void tf_serialize_store(tf_task_t* task, tf_taskstub_t* to, void** out_buffer, size_t* out_size, JSValue value)
{
	buffer_t tmp = { 0 };
	_serialize_store(task, to, &tmp, value);
	tmp.data = tf_realloc(tmp.data, tmp.size);
	*out_buffer = tmp.data;
	*out_size = tmp.size;
}

JSValue tf_serialize_load(tf_task_t* task, tf_taskstub_t* from, const char* buffer, size_t size)
{
	return _serialize_load(task, from, buffer, size);
}

static void _buffer_append(buffer_t* buffer, const void* data, size_t size)
{
	if (buffer->capacity < buffer->size + size)
	{
		size_t new_capacity = (size + buffer->capacity) * 2;
		buffer->data = tf_realloc(buffer->data, new_capacity);
		buffer->capacity = new_capacity;
	}
	memcpy((char*)buffer->data + buffer->size, data, size);
	buffer->size += size;
}

void _serialize_writeInt8(buffer_t* buffer, int8_t value)
{
	_buffer_append(buffer, &value, sizeof(value));
}

void _serialize_writeInt32(buffer_t* buffer, int32_t value)
{
	_buffer_append(buffer, &value, sizeof(value));
}

void _serialize_writeInt64(buffer_t* buffer, int64_t value)
{
	_buffer_append(buffer, &value, sizeof(value));
}

void _serialize_writeDouble(buffer_t* buffer, double value)
{
	_buffer_append(buffer, &value, sizeof(value));
}

static void _serialize_read(const char** buffer, size_t* size, void* target, size_t target_size)
{
	assert(*size >= target_size);
	memcpy(target, *buffer, target_size);
	*buffer += target_size;
	*size -= target_size;
}

static int8_t _serialize_readInt8(const char** buffer, size_t* size)
{
	int8_t result;
	_serialize_read(buffer, size, &result, sizeof(result));
	return result;
}

int32_t _serialize_readInt32(const char** buffer, size_t* size)
{
	int32_t result;
	_serialize_read(buffer, size, &result, sizeof(result));
	return result;
}

int64_t _serialize_readInt64(const char** buffer, size_t* size)
{
	int64_t result;
	_serialize_read(buffer, size, &result, sizeof(result));
	return result;
}

double _serialize_readDouble(const char** buffer, size_t* size)
{
	double result;
	_serialize_read(buffer, size, &result, sizeof(result));
	return result;
}

static bool _serialize_store(tf_task_t* task, tf_taskstub_t* to, buffer_t* buffer, JSValue value)
{
	return _serialize_storeInternal(task, to, buffer, value, 0);
}

static bool _serialize_storeInternal(tf_task_t* task, tf_taskstub_t* to, buffer_t* buffer, JSValue value, int depth)
{
	JSContext* context = tf_task_get_context(task);
	size_t size;
	size_t offset;
	size_t element_size;
	JSValue typed;
	uint8_t* bytes;
	if (JS_IsUndefined(value))
	{
		_serialize_writeInt32(buffer, kUndefined);
	}
	else if (JS_IsUninitialized(value))
	{
		_serialize_writeInt32(buffer, kUninitialized);
	}
	else if (JS_IsNull(value))
	{
		_serialize_writeInt32(buffer, kNull);
	}
	else if (JS_IsBool(value))
	{
		_serialize_writeInt32(buffer, kBoolean);
		_serialize_writeInt8(buffer, JS_ToBool(tf_task_get_context(task), value) ? 1 : 0);
	}
	else if (JS_IsNumber(value))
	{
		int64_t result = 0;
		if (JS_ToInt64(tf_task_get_context(task), &result, value) == 0)
		{
			_serialize_writeInt32(buffer, kInt64);
			_serialize_writeInt64(buffer, result);
		}
		else
		{
			fprintf(stderr, "Unable to store integer.\n");
		}
	}
	else if (JS_IsNumber(value))
	{
		double result = 0.0;
		if (JS_ToFloat64(tf_task_get_context(task), &result, value) == 0)
		{
			_serialize_writeInt32(buffer, kNumber);
			_serialize_writeDouble(buffer, result);
		}
		else
		{
			fprintf(stderr, "Unable to store number.\n");
		}
	}
	else if (JS_IsException(value))
	{
		JSValue exception = JS_GetException(context);
		const char* message = JS_ToCString(context, exception);

		JSValue error = JS_NewObject(context);
		JS_SetPropertyStr(context, error, "message", JS_NewString(context, message ? message : "[exception]"));

		if (JS_IsError(context, exception))
		{
			JSValue stack = JS_GetPropertyStr(context, exception, "stack");
			if (!JS_IsUndefined(stack) && !JS_IsException(stack))
			{
				JS_SetPropertyStr(context, error, "stack", JS_DupValue(context, stack));
			}
			JS_FreeValue(context, stack);
		}
		_serialize_writeInt32(buffer, kException);
		_serialize_storeInternal(task, to, buffer, error, depth + 1);
		JS_FreeCString(context, message);
		JS_FreeValue(context, error);
		JS_FreeValue(context, exception);
	}
	else if (JS_IsString(value))
	{
		size_t len = 0;
		const char* result = JS_ToCStringLen(tf_task_get_context(task), &len, value);
		_serialize_writeInt32(buffer, kString);
		_serialize_writeInt32(buffer, (int32_t)len);
		_buffer_append(buffer, result, len);
		JS_FreeCString(tf_task_get_context(task), result);
	}
	else if ((bytes = tf_util_try_get_array_buffer(tf_task_get_context(task), &size, value)) != 0)
	{
		_serialize_writeInt32(buffer, kArrayBuffer);
		_serialize_writeInt32(buffer, (int32_t)size);
		_buffer_append(buffer, bytes, size);
	}
	else if (!JS_IsException((typed = tf_util_try_get_typed_array_buffer(tf_task_get_context(task), value, &offset, &size, &element_size))))
	{
		size_t total_size;
		uint8_t* bytes = tf_util_try_get_array_buffer(tf_task_get_context(task), &total_size, typed);
		_serialize_writeInt32(buffer, kArrayBuffer);
		_serialize_writeInt32(buffer, (int32_t)size);
		_buffer_append(buffer, bytes, size);
		JS_FreeValue(tf_task_get_context(task), typed);
	}
	else if (JS_IsArray(tf_task_get_context(task), value))
	{
		_serialize_writeInt32(buffer, kArray);
		JSValue length_val = JS_GetPropertyStr(tf_task_get_context(task), value, "length");
		int length;
		if (JS_ToInt32(tf_task_get_context(task), &length, length_val) == 0)
		{
			_serialize_writeInt32(buffer, length);
			for (int i = 0; i < length; ++i)
			{
				JSValue element = JS_GetPropertyUint32(tf_task_get_context(task), value, i);
				_serialize_storeInternal(task, to, buffer, element, depth + 1);
				JS_FreeValue(context, element);
			}
		}
		else
		{
			_serialize_writeInt32(buffer, 0);
		}
		JS_FreeValue(tf_task_get_context(task), length_val);
	}
	else if (JS_IsFunction(tf_task_get_context(task), value))
	{
		_serialize_writeInt32(buffer, kFunction);
		exportid_t exportId = tf_task_export_function(task, to, value);
		_serialize_writeInt32(buffer, exportId);
	}
	else if (JS_IsError(tf_task_get_context(task), value))
	{
		_serialize_writeInt32(buffer, kError);
		JSPropertyEnum* ptab;
		uint32_t plen;
		JS_GetOwnPropertyNames(tf_task_get_context(task), &ptab, &plen, value, JS_GPN_STRING_MASK);
		_serialize_writeInt32(buffer, plen);
		for (uint32_t i = 0; i < plen; ++i)
		{
			JSValue key = JS_AtomToString(tf_task_get_context(task), ptab[i].atom);
			JSPropertyDescriptor desc;
			JSValue key_value = JS_NULL;
			if (JS_GetOwnProperty(tf_task_get_context(task), &desc, value, ptab[i].atom) == 1)
			{
				key_value = desc.value;
				JS_FreeValue(tf_task_get_context(task), desc.setter);
				JS_FreeValue(tf_task_get_context(task), desc.getter);
			}
			_serialize_storeInternal(task, to, buffer, key, depth + 1);
			_serialize_storeInternal(task, to, buffer, key_value, depth + 1);
			JS_FreeValue(tf_task_get_context(task), key);
			JS_FreeValue(tf_task_get_context(task), key_value);
		}
		for (uint32_t i = 0; i < plen; ++i)
		{
			JS_FreeAtom(tf_task_get_context(task), ptab[i].atom);
		}
		js_free(tf_task_get_context(task), ptab);
	}
	else if (JS_IsObject(value))
	{
		_serialize_writeInt32(buffer, kObject);
		JSPropertyEnum* ptab;
		uint32_t plen;
		JS_GetOwnPropertyNames(tf_task_get_context(task), &ptab, &plen, value, JS_GPN_STRING_MASK);
		_serialize_writeInt32(buffer, plen);
		for (uint32_t i = 0; i < plen; ++i)
		{
			JSValue key = JS_AtomToString(tf_task_get_context(task), ptab[i].atom);
			JSPropertyDescriptor desc;
			JSValue key_value = JS_NULL;
			if (JS_GetOwnProperty(tf_task_get_context(task), &desc, value, ptab[i].atom) == 1)
			{
				key_value = desc.value;
				JS_FreeValue(tf_task_get_context(task), desc.setter);
				JS_FreeValue(tf_task_get_context(task), desc.getter);
			}
			_serialize_storeInternal(task, to, buffer, key, depth + 1);
			_serialize_storeInternal(task, to, buffer, key_value, depth + 1);
			JS_FreeValue(tf_task_get_context(task), key);
			JS_FreeValue(tf_task_get_context(task), key_value);
		}
		for (uint32_t i = 0; i < plen; ++i)
		{
			JS_FreeAtom(tf_task_get_context(task), ptab[i].atom);
		}
		js_free(tf_task_get_context(task), ptab);
	}
	else
	{
		fprintf(stderr, "Unknown JSValue type: %d.\n", JS_VALUE_GET_TAG(value));
		abort();
	}

	return true;
}

static JSValue _serialize_load(tf_task_t* task, tf_taskstub_t* from, const char* buffer, size_t size)
{
	return _serialize_loadInternal(task, from, &buffer, &size, 0);
}

static JSValue _serialize_loadInternal(tf_task_t* task, tf_taskstub_t* from, const char** buffer, size_t* size, int depth)
{
	if (*size < sizeof(int32_t))
	{
		return JS_UNDEFINED;
	}
	else
	{
		int32_t type = _serialize_readInt32(buffer, size);
		JSValue result = JS_UNDEFINED;

		switch (type)
		{
		case kUndefined:
			result = JS_UNDEFINED;
			break;
		case kNull:
			result = JS_NULL;
			break;
		case kUninitialized:
			result = JS_UNINITIALIZED;
			break;
		case kBoolean:
			result = JS_NewBool(tf_task_get_context(task), _serialize_readInt8(buffer, size) != 0);
			break;
		case kInt32:
			result = JS_NewInt32(tf_task_get_context(task), _serialize_readInt32(buffer, size));
			break;
		case kInt64:
			result = JS_NewInt64(tf_task_get_context(task), _serialize_readInt64(buffer, size));
			break;
		case kNumber:
			result = JS_NewFloat64(tf_task_get_context(task), _serialize_readDouble(buffer, size));
			break;
		case kString:
			{
				int32_t length = _serialize_readInt32(buffer, size);
				result = JS_NewStringLen(tf_task_get_context(task), *buffer, length);
				*buffer += length;
				*size -= length;
			}
			break;
		case kArrayBuffer:
			{
				int32_t length = _serialize_readInt32(buffer, size);
				result = JS_NewArrayBufferCopy(tf_task_get_context(task), (const uint8_t*)*buffer, length);
				*buffer += length;
				*size -= length;
			}
			break;
		case kArray:
			{
				int32_t length = _serialize_readInt32(buffer, size);
				result = JS_NewArray(tf_task_get_context(task));
				for (int i = 0; i < length; ++i)
				{
					JS_SetPropertyUint32(tf_task_get_context(task), result, i, _serialize_loadInternal(task, from, buffer, size, depth + 1));
				}
			}
			break;
		case kFunction:
			{
				exportid_t exportId = _serialize_readInt32(buffer, size);
				result = tf_task_add_import(task, tf_taskstub_get_id(from), exportId);
			}
			break;
		case kException:
			{
				_serialize_readInt32(buffer, size);
				JSValue error = JS_NewError(tf_task_get_context(task));
				int32_t length = _serialize_readInt32(buffer, size);
				for (int i = 0; i < length; ++i)
				{
					JSValue key = _serialize_loadInternal(task, from, buffer, size, depth + 1);
					JSValue value = _serialize_loadInternal(task, from, buffer, size, depth + 1);
					const char* key_str = JS_ToCString(tf_task_get_context(task), key);
					JS_SetPropertyStr(tf_task_get_context(task), error, key_str, value);
					JS_FreeCString(tf_task_get_context(task), key_str);
					JS_FreeValue(tf_task_get_context(task), key);
				}
				result = error;
			}
			break;
		case kError:
		case kObject:
			{
				int32_t length = _serialize_readInt32(buffer, size);
				result = JS_NewObject(tf_task_get_context(task));
				for (int i = 0; i < length; ++i)
				{
					JSValue key = _serialize_loadInternal(task, from, buffer, size, depth + 1);
					JSValue value = _serialize_loadInternal(task, from, buffer, size, depth + 1);
					const char* key_str = JS_ToCString(tf_task_get_context(task), key);
					JS_SetPropertyStr(tf_task_get_context(task), result, key_str, value);
					JS_FreeCString(tf_task_get_context(task), key_str);
					JS_FreeValue(tf_task_get_context(task), key);
				}
			}
			break;
		default:
			abort();
			break;
		}
		return result;
	}
}