#!/usr/bin/env python3

from python_sdk_api.sx_api import *
import inspect
import re

DEVICE_ID = 1
SWITCH_ID = 0
PORT_TABLE = 'PORT'
FIRST_LANE_INDEX = 0
ETHERNET_PREFIX = 'Ethernet'

def get_ports_lanes_map(config_db):
    """ Get lane number of the first lane in use by port for all existing ports.

    Args:
        config_db (ConfigDBConnector): Config DB connector

    Returns:
        dict: key is lane number of the first lane in use by port, value is SONiC port index (124 for Ethernet124)
    """
    lanes_map = {}
    config_db.connect()

    ports_table = config_db.get_table(PORT_TABLE)
    if ports_table is None:
        raise Exception("Can't read {} table".format(PORT_TABLE))

    ports_table_keys = config_db.get_keys(PORT_TABLE)
    for port in ports_table_keys:
        port_data = ports_table.get(port)
        if port_data is not None:
            lanes = port_data.get('lanes')
            first_lane = lanes.split(',')[FIRST_LANE_INDEX]
            port_idx = re.sub(r"\D", "", port)
            lanes_map[int(first_lane)] = int(port_idx)

    return lanes_map

def get_port_max_width(handle):
    """ Get max number of lanes in port according to chip type

    Args:
        handle (sx_api_handle_t): SDK handle

    Returns:
        int: max lanes in port
    """
    # Get chip type
    chip_type = sx_get_chip_type(handle)

    limits = rm_resources_t()
    modes = rm_modes_t()

    rc = rm_chip_limits_get(chip_type, limits)
    sx_check_rc(rc)
    max_width = limits.port_map_width_max

    # SPC2 ports have 8 lanes but SONiC is using 4
    if chip_type == SX_CHIP_TYPE_SPECTRUM2:
        max_width = 4

    return max_width

def sx_get_ports_map(handle, config_db):
    """ Get ports map from SDK logical index to SONiC index
    
    Args:
        handle (sx_api_handle_t): SDK handle
        config_db (ConfigDBConnector): Config DB connector

    Returns:
        dict: key is SDK logical index, value is SONiC index (4 for Ethernet4)
    """         
    try:
        ports_map = {}
        port_attributes_list = None
        port_cnt_p = None
        
        # Get lanes map
        lanes_map = get_ports_lanes_map(config_db)

        # Get max number of lanes in port
        port_max_width = get_port_max_width(handle)
        
        # Get ports count
        port_cnt_p = new_uint32_t_p()
        rc = sx_api_port_device_get(handle, DEVICE_ID, SWITCH_ID, None,  port_cnt_p)
        sx_check_rc(rc)
        
        # Get ports
        port_cnt = uint32_t_p_value(port_cnt_p)
        port_attributes_list = new_sx_port_attributes_t_arr(port_cnt)
        rc = sx_api_port_device_get(handle, DEVICE_ID, SWITCH_ID, port_attributes_list,  port_cnt_p)
        sx_check_rc(rc)
        
        for i in range(0, port_cnt):
            port_attributes = sx_port_attributes_t_arr_getitem(port_attributes_list, i)
            label_port = port_attributes.port_mapping.module_port
            logical_port = port_attributes.log_port;
            lane_bmap = port_attributes.port_mapping.lane_bmap;
            
            if (is_phy_port(port_attributes.log_port) == False):
                continue
            
            # Calculate sonic index (sonic index=4 for Ethernet4)
            lane_index = get_lane_index(lane_bmap, port_max_width)
            assert lane_index != -1, "Failed to calculate port index"
            
            first_lane = label_port * port_max_width + lane_index;
            sonic_index = lanes_map[first_lane]

            sonic_interface = ETHERNET_PREFIX + str(sonic_index)    
            ports_map[logical_port] = sonic_interface
            
        return ports_map
    
    finally:
        delete_sx_port_attributes_t_arr(port_attributes_list)
        delete_uint32_t_p(port_cnt_p)
        
def sx_get_chip_type(handle):
    """ Get system ASIC type
    
    Args:
        handle (sx_api_handle_t): SDK handle
    
    Returns:
        sx_chip_types_t: Chip type
    """       
    try:
        device_info_cnt_p = new_uint32_t_p()
        uint32_t_p_assign(device_info_cnt_p, 1)
        device_info_cnt = uint32_t_p_value(device_info_cnt_p)
        device_info_list_p = new_sx_device_info_t_arr(device_info_cnt)
        
        rc = sx_api_port_device_list_get(handle, device_info_list_p, device_info_cnt_p)
        sx_check_rc(rc)
    
        device_info = sx_device_info_t_arr_getitem(device_info_list_p, SWITCH_ID)
        chip_type = device_info.dev_type
        if chip_type == SX_CHIP_TYPE_SPECTRUM_A1:
            chip_type = SX_CHIP_TYPE_SPECTRUM
            
        return chip_type
    
    finally:
        delete_sx_device_info_t_arr(device_info_list_p)
        delete_uint32_t_p(device_info_cnt_p)

def get_lane_index(lane_bmap, max_lanes):
   """ Get index of first lane in use (2 for 00001100)
   
   Args:
       lane_bmap (int): bitmap indicating module lanes in use
       max_lanes (int): Max lanes in module

   Returns:
       int: index of the first bit set to 1 in lane_bmap
   """       
   for lane_idx in range(0, max_lanes):
       if (lane_bmap & 0x1 == 1):
           return lane_idx
       lane_bmap = lane_bmap >> 1
       
def sx_check_rc(rc):
    if rc is not SX_STATUS_SUCCESS:
        # Get the calling function name from the last frame
        cf = inspect.currentframe().f_back
        func_name = inspect.getframeinfo(cf).function
        error_info = func_name + ' failed with rc = ' + str(rc)
    
        raise Exception(error_info)       

def get_port_type(log_port_id):
    return (log_port_id & SX_PORT_TYPE_ID_MASK) >> SX_PORT_TYPE_ID_OFFS

def is_phy_port(log_port_id):
    return get_port_type(log_port_id) == SX_PORT_TYPE_NETWORK

def is_lag(log_port_id):
    return get_port_type(log_port_id) == SX_PORT_TYPE_LAG