#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
根据client.proto生成的解析代码 (V2 - 已修复解码逻辑)
适用于ESP32 MicroPython环境
"""

import struct


# --- Protobuf基础类型辅助函数 ---

def encode_varint(value):
    buf = bytearray()
    while value >= 0x80:
        buf.append((value & 0x7F) | 0x80)
        value >>= 7
    buf.append(value & 0x7F)
    return buf


def decode_varint(buf, pos=0):
    result = 0
    shift = 0
    while pos < len(buf):
        byte = buf[pos]
        pos += 1
        result |= (byte & 0x7F) << shift
        if not (byte & 0x80):
            break
        shift += 7
    return result, pos


def encode_string(value):
    value_bytes = value.encode('utf-8')
    length = encode_varint(len(value_bytes))
    return length + value_bytes


def decode_string(buf, pos=0):
    """解码字符串 (已修复)"""
    length, pos_after_len = decode_varint(buf, pos)
    end_pos = pos_after_len + length
    value = buf[pos_after_len:end_pos].decode('utf-8')
    return value, end_pos


# --- 消息编码/解码函数 ---

def encode_raw_485_command(bus_number, command_bytes):
    result = bytearray()
    result.extend(encode_varint((1 << 3) | 0))
    result.extend(encode_varint(bus_number))
    result.extend(encode_varint((2 << 3) | 2))
    result.extend(encode_varint(len(command_bytes)))
    result.extend(command_bytes)
    return result


def decode_raw_485_command(buf):
    """解码Raw485Command消息 (已修复)"""
    result = {}
    pos = 0
    while pos < len(buf):
        tag, pos = decode_varint(buf, pos)
        field_number = tag >> 3
        wire_type = tag & 0x07

        if field_number == 1:  # bus_number
            value, pos = decode_varint(buf, pos)
            result['bus_number'] = value
        elif field_number == 2:  # command_bytes
            length, pos_after_len = decode_varint(buf, pos)
            end_pos = pos_after_len + length
            result['command_bytes'] = buf[pos_after_len:end_pos]
            pos = end_pos
        else:
            # 跳过未知字段
            if wire_type == 0:
                _, pos = decode_varint(buf, pos)
            elif wire_type == 2:
                length, pos_after_len = decode_varint(buf, pos)
                pos = pos_after_len + length
            elif wire_type == 5:
                pos += 4
            else:
                pos += 1
    return result


def encode_collect_task(command_msg):
    result = bytearray()
    encoded_command = encode_raw_485_command(command_msg['bus_number'], command_msg['command_bytes'])
    result.extend(encode_varint((1 << 3) | 2))
    result.extend(encode_varint(len(encoded_command)))
    result.extend(encoded_command)
    return result


def decode_collect_task(buf):
    """解码CollectTask消息 (已修复)"""
    result = {}
    pos = 0
    while pos < len(buf):
        tag, pos = decode_varint(buf, pos)
        field_number = tag >> 3
        wire_type = tag & 0x07

        if field_number == 1:  # command
            length, pos_after_len = decode_varint(buf, pos)
            end_pos = pos_after_len + length
            value_buf = buf[pos_after_len:end_pos]
            result['command'] = decode_raw_485_command(value_buf)
            pos = end_pos
        else:
            if wire_type == 0:
                _, pos = decode_varint(buf, pos)
            elif wire_type == 2:
                length, pos_after_len = decode_varint(buf, pos)
                pos = pos_after_len + length
            elif wire_type == 5:
                pos += 4
            else:
                pos += 1
    return result


def encode_batch_collect_command(correlation_id, tasks):
    result = bytearray()
    result.extend(encode_varint((1 << 3) | 2))
    result.extend(encode_string(correlation_id))
    for task in tasks:
        encoded_task = encode_collect_task(task['command'])
        result.extend(encode_varint((2 << 3) | 2))
        result.extend(encode_varint(len(encoded_task)))
        result.extend(encoded_task)
    return result


def decode_batch_collect_command(buf):
    """解码BatchCollectCommand消息 (已修复)"""
    result = {'tasks': []}
    pos = 0
    while pos < len(buf):
        tag, pos = decode_varint(buf, pos)
        field_number = tag >> 3
        wire_type = tag & 0x07

        if field_number == 1:  # correlation_id
            value, pos = decode_string(buf, pos)
            result['correlation_id'] = value
        elif field_number == 2:  # tasks (repeated)
            length, pos_after_len = decode_varint(buf, pos)
            end_pos = pos_after_len + length
            value_buf = buf[pos_after_len:end_pos]
            result['tasks'].append(decode_collect_task(value_buf))
            pos = end_pos
        else:
            if wire_type == 0:
                _, pos = decode_varint(buf, pos)
            elif wire_type == 2:
                length, pos_after_len = decode_varint(buf, pos)
                pos = pos_after_len + length
            elif wire_type == 5:
                pos += 4
            else:
                pos += 1
    return result


def encode_collect_result(correlation_id, values):
    result = bytearray()
    result.extend(encode_varint((1 << 3) | 2))
    result.extend(encode_string(correlation_id))
    for value in values:
        result.extend(encode_varint((2 << 3) | 5))
        result.extend(struct.pack('<f', value))
    return result


def decode_collect_result(buf):
    """解码CollectResult消息 (已修复)"""
    result = {'values': []}
    pos = 0
    while pos < len(buf):
        tag, pos = decode_varint(buf, pos)
        field_number = tag >> 3
        wire_type = tag & 0x07

        if field_number == 1:  # correlation_id
            value, pos = decode_string(buf, pos)
            result['correlation_id'] = value
        elif field_number == 2:  # values (repeated)
            if wire_type == 5:  # fixed32
                value = struct.unpack('<f', buf[pos:pos + 4])[0]
                pos += 4
                result['values'].append(value)
        else:
            if wire_type == 0:
                _, pos = decode_varint(buf, pos)
            elif wire_type == 2:
                length, pos_after_len = decode_varint(buf, pos)
                pos = pos_after_len + length
            elif wire_type == 5:
                pos += 4
            else:
                pos += 1
    return result


def encode_instruction(payload_type, payload_data):
    result = bytearray()
    encoded_payload = bytearray()

    if payload_type == 'raw_485_command':
        encoded_payload = encode_raw_485_command(payload_data['bus_number'], payload_data['command_bytes'])
        result.extend(encode_varint((1 << 3) | 2))
    elif payload_type == 'batch_collect_command':
        encoded_payload = encode_batch_collect_command(payload_data['correlation_id'], payload_data['tasks'])
        result.extend(encode_varint((2 << 3) | 2))
    elif payload_type == 'collect_result':
        encoded_payload = encode_collect_result(payload_data['correlation_id'], payload_data['values'])
        result.extend(encode_varint((3 << 3) | 2))
    else:
        raise ValueError("未知的指令负载类型")

    result.extend(encode_varint(len(encoded_payload)))
    result.extend(encoded_payload)
    return result


def decode_instruction(buf):
    """解码Instruction消息 (已修复)"""
    result = {}
    pos = 0
    while pos < len(buf):
        tag, pos = decode_varint(buf, pos)
        field_number = tag >> 3
        wire_type = tag & 0x07

        if wire_type == 2:
            length, pos_after_len = decode_varint(buf, pos)
            end_pos = pos_after_len + length
            value_buf = buf[pos_after_len:end_pos]

            if field_number == 1:
                result['raw_485_command'] = decode_raw_485_command(value_buf)
            elif field_number == 2:
                result['batch_collect_command'] = decode_batch_collect_command(value_buf)
            elif field_number == 3:
                result['collect_result'] = decode_collect_result(value_buf)
            
            pos = end_pos
        else:
            if wire_type == 0:
                _, pos = decode_varint(buf, pos)
            elif wire_type == 5:
                pos += 4
            else:
                pos += 1
    return result


# --- 单元测试与使用范例 ---
if __name__ == "__main__":
    print("--- 测试 Raw485Command ---")
    raw_cmd_data = {'bus_number': 1, 'command_bytes': b'\x01\x03\x00\x00\x00\x02\xc4\x0b'}
    encoded_raw_cmd = encode_raw_485_command(raw_cmd_data['bus_number'], raw_cmd_data['command_bytes'])
    decoded_raw_cmd = decode_raw_485_command(encoded_raw_cmd)
    assert decoded_raw_cmd == raw_cmd_data, f"Expected {raw_cmd_data}, got {decoded_raw_cmd}"

    print("\n--- 测试 CollectTask ---")
    collect_task_data = {'command': raw_cmd_data}
    encoded_collect_task = encode_collect_task(collect_task_data['command'])
    decoded_collect_task = decode_collect_task(encoded_collect_task)
    assert decoded_collect_task == collect_task_data, f"Expected {collect_task_data}, got {decoded_collect_task}"

    print("\n--- 测试 BatchCollectCommand ---")
    batch_collect_data = {
        'correlation_id': 'abc-123',
        'tasks': [
            {'command': {'bus_number': 1, 'command_bytes': b'\x01\x04\x00\x01\x00\x01\x60\x0a'}},
            {'command': {'bus_number': 2, 'command_bytes': b'\x02\x03\x00\x01\x00\x01\xd5\xfa'}}
        ]
    }
    encoded_batch_collect = encode_batch_collect_command(batch_collect_data['correlation_id'], batch_collect_data['tasks'])
    decoded_batch_collect = decode_batch_collect_command(encoded_batch_collect)
    assert decoded_batch_collect == batch_collect_data, f"Expected {batch_collect_data}, got {decoded_batch_collect}"

    print("\n--- 测试 CollectResult ---")
    collect_result_data = {'correlation_id': 'res-456', 'values': [12.34, 56.78]}
    encoded_collect_result = encode_collect_result(collect_result_data['correlation_id'], collect_result_data['values'])
    decoded_collect_result = decode_collect_result(encoded_collect_result)
    assert decoded_collect_result['correlation_id'] == collect_result_data['correlation_id']
    for i in range(len(collect_result_data['values'])):
        assert abs(decoded_collect_result['values'][i] - collect_result_data['values'][i]) < 1e-5

    print("\n--- 测试 Instruction (内含BatchCollectCommand) ---")
    instruction_batch_collect = encode_instruction('batch_collect_command', batch_collect_data)
    decoded_instruction_batch_collect = decode_instruction(instruction_batch_collect)
    assert decoded_instruction_batch_collect == {'batch_collect_command': batch_collect_data}

    print("\n所有测试均已通过!")