# This file is Copyright (c) 2015-2018 Florent Kermarrec <florent@enjoy-digital.fr>
# License: BSD

from math import ceil

from migen import *

from litex.gen import *

from litex.soc.interconnect import stream
from litex.soc.interconnect.stream import EndpointDescription
from litex.soc.interconnect.csr import *

from litex.soc.interconnect.packet import Header, HeaderField


class Port:
    def connect(self, port):
        r = [self.source.connect(port.sink),
             port.source.connect(self.sink)]
        return r


eth_mtu = 1530
eth_min_len = 46
eth_interpacket_gap = 12
eth_preamble = 0xd555555555555555
buffer_depth = 2**log2_int(eth_mtu, need_pow2=False)

ethernet_type_ip = 0x800
ethernet_type_arp = 0x806

mac_header_length = 14
mac_header_fields = {
    "target_mac":    HeaderField(0,  0, 48),
    "sender_mac":    HeaderField(6,  0, 48),
    "ethernet_type": HeaderField(12, 0, 16)
}
mac_header = Header(mac_header_fields,
                    mac_header_length,
                    swap_field_bytes=True)

arp_hwtype_ethernet = 0x0001
arp_proto_ip = 0x0800
arp_opcode_request = 0x0001
arp_opcode_reply = 0x0002

arp_header_length = 28
arp_header_fields = {
    "hwtype":     HeaderField(0,  0, 16),
    "proto":      HeaderField(2,  0, 16),
    "hwsize":     HeaderField(4,  0,  8),
    "protosize":  HeaderField(5,  0,  8),
    "opcode":     HeaderField(6,  0, 16),
    "sender_mac": HeaderField(8,  0, 48),
    "sender_ip":  HeaderField(14, 0, 32),
    "target_mac": HeaderField(18, 0, 48),
    "target_ip":  HeaderField(24, 0, 32)
}
arp_header = Header(arp_header_fields,
                    arp_header_length,
                    swap_field_bytes=True)


ipv4_header_length = 20
ipv4_header_fields = {
    "ihl":            HeaderField(0,  0,  4),
    "version":        HeaderField(0,  4,  4),
    "total_length":   HeaderField(2,  0, 16),
    "identification": HeaderField(4,  0, 16),
    "ttl":            HeaderField(8,  0,  8),
    "protocol":       HeaderField(9,  0,  8),
    "checksum":       HeaderField(10, 0, 16),
    "sender_ip":      HeaderField(12, 0, 32),
    "target_ip":      HeaderField(16, 0, 32)
}
ipv4_header = Header(ipv4_header_fields,
                     ipv4_header_length,
                     swap_field_bytes=True)

icmp_protocol = 0x01

icmp_header_length = 8
icmp_header_fields = {
    "msgtype":  HeaderField(0, 0,  8),
    "code":     HeaderField(1, 0,  8),
    "checksum": HeaderField(2, 0, 16),
    "quench":   HeaderField(4, 0, 32)
}
icmp_header  = Header(icmp_header_fields,
                      icmp_header_length,
                      swap_field_bytes=True)

udp_protocol = 0x11

udp_header_length = 8
udp_header_fields = {
    "src_port": HeaderField(0, 0, 16),
    "dst_port": HeaderField(2, 0, 16),
    "length":   HeaderField(4, 0, 16),
    "checksum": HeaderField(6, 0, 16)
}
udp_header = Header(udp_header_fields,
                    udp_header_length,
                    swap_field_bytes=True)


etherbone_magic = 0x4e6f
etherbone_version = 1
etherbone_packet_header_length = 8
etherbone_packet_header_fields = {
    "magic":     HeaderField(0, 0, 16),

    "version":   HeaderField(2, 4,  4),
    "nr":        HeaderField(2, 2,  1),
    "pr":        HeaderField(2, 1,  1),
    "pf":        HeaderField(2, 0,  1),

    "addr_size": HeaderField(3, 4,  4),
    "port_size": HeaderField(3, 0,  4)
}
etherbone_packet_header = Header(etherbone_packet_header_fields,
                                 etherbone_packet_header_length,
                                 swap_field_bytes=True)

etherbone_record_header_length = 4
etherbone_record_header_fields = {
    "bca":         HeaderField(0, 0, 1),
    "rca":         HeaderField(0, 1, 1),
    "rff":         HeaderField(0, 2, 1),
    "cyc":         HeaderField(0, 4, 1),
    "wca":         HeaderField(0, 5, 1),
    "wff":         HeaderField(0, 6, 1),

    "byte_enable": HeaderField(1, 0, 8),

    "wcount":      HeaderField(2, 0, 8),

    "rcount":      HeaderField(3, 0, 8)
}
etherbone_record_header = Header(etherbone_record_header_fields,
                                 etherbone_record_header_length,
                                 swap_field_bytes=True)

# layouts
def _remove_from_layout(layout, *args):
    r = []
    for f in layout:
        remove = False
        for arg in args:
            if f[0] == arg:
                remove = True
        if not remove:
            r.append(f)
    return r

def eth_phy_description(dw):
    payload_layout = [
        ("data",       dw),
        ("last_be", dw//8),
        ("error",   dw//8)
    ]
    return EndpointDescription(payload_layout)

def eth_mac_description(dw):
    payload_layout = mac_header.get_layout() + [
        ("data",       dw),
        ("last_be", dw//8),
        ("error",   dw//8)
    ]
    return EndpointDescription(payload_layout)

def eth_arp_description(dw):
    param_layout = arp_header.get_layout()
    payload_layout = [
        ("data",     dw),
        ("error", dw//8)
    ]
    return EndpointDescription(payload_layout, param_layout)

arp_table_request_layout = [
    ("ip_address", 32)
]

arp_table_response_layout = [
    ("failed",       1),
    ("mac_address", 48)
]

def eth_ipv4_description(dw):
    param_layout = ipv4_header.get_layout()
    payload_layout = [
        ("data",     dw),
        ("error", dw//8)
    ]
    return EndpointDescription(payload_layout, param_layout)

def eth_ipv4_user_description(dw):
    param_layout = [
        ("length",     16),
        ("protocol",    8),
        ("ip_address", 32)
    ]
    payload_layout = [
        ("data",     dw),
        ("error", dw//8)
    ]
    return EndpointDescription(payload_layout, param_layout)

def convert_ip(s):
    ip = 0
    for e in s.split("."):
        ip = ip << 8
        ip += int(e)
    return ip

def eth_icmp_description(dw):
    param_layout = icmp_header.get_layout()
    payload_layout = [
        ("data",     dw),
        ("error", dw//8)
    ]
    return EndpointDescription(payload_layout, param_layout)

def eth_icmp_user_description(dw):
    param_layout = icmp_header.get_layout() + [
        ("ip_address", 32),
        ("length",     16)
    ]
    payload_layout = [
        ("data",     dw),
        ("error", dw//8)
    ]
    return EndpointDescription(payload_layout, param_layout)

def eth_udp_description(dw):
    param_layout = udp_header.get_layout()
    payload_layout = [
        ("data",     dw),
        ("error", dw//8)
    ]
    return EndpointDescription(payload_layout, param_layout)

def eth_udp_user_description(dw):
    param_layout = [
        ("src_port",   16),
        ("dst_port",   16),
        ("ip_address", 32),
        ("length",     16)
    ]
    payload_layout = [
        ("data",     dw),
        ("error", dw//8)
    ]
    return EndpointDescription(payload_layout, param_layout)

def eth_etherbone_packet_description(dw):
    param_layout = etherbone_packet_header.get_layout()
    payload_layout = [
        ("data",     dw),
        ("error", dw//8)
    ]
    return EndpointDescription(payload_layout, param_layout)

def eth_etherbone_packet_user_description(dw):
    param_layout = etherbone_packet_header.get_layout()
    param_layout = _remove_from_layout(param_layout,
                                       "magic",
                                       "portsize",
                                       "addrsize",
                                       "version")
    param_layout += eth_udp_user_description(dw).param_layout
    payload_layout = [
        ("data",     dw),
        ("error", dw//8)
    ]
    return EndpointDescription(payload_layout, param_layout)

def eth_etherbone_record_description(dw):
    param_layout = etherbone_record_header.get_layout()
    payload_layout = [
        ("data",     dw),
        ("error", dw//8)
    ]
    return EndpointDescription(payload_layout, param_layout)

def eth_etherbone_mmap_description(dw):
    param_layout = [
        ("we",            1),
        ("count",         8),
        ("base_addr",    32),
        ("be",        dw//8)
    ]
    payload_layout = [
        ("addr", 32),
        ("data", dw)
    ]
    return EndpointDescription(payload_layout, param_layout)

def eth_tty_description(dw):
    payload_layout = [("data", dw)]
    return EndpointDescription(payload_layout)
