#!/usr/bin/env python3

import collections
import itertools
import os
import re
import subprocess
import sys
import os

PUC = os.getenv("PAMU2FCFG", "../pamu2fcfg/pamu2fcfg")

resident = ["", "-r"]

presence = ["", "-P"]

pin = ["", "-N"]

verification = ["", "-V"]

Credential = collections.namedtuple(
    "Credential", "keyhandle pubkey attributes oldformat"
)


def read_credentials(filename):
    with open(filename, "r") as handle:
        line = handle.readline()

    credentials = []
    for credstr in line.split(":")[1:]:
        matches = re.match(r"^(.*?),(.*?),es256,(.*)$", credstr, re.M)
        credentials.append(
            Credential(
                keyhandle=matches.group(1),
                pubkey=matches.group(2),
                attributes=matches.group(3),
                oldformat=0,
            )
        )
    return credentials


def print_test_case(filename, credentials):
    start = """\
  dev = calloc(cfg.max_devs, sizeof(*dev));
  assert(dev != NULL);
  cfg.auth_file = "{authfile}";
  rc = get_devices_from_authfile(&cfg, username, dev, &n_devs);
  assert(rc == PAM_SUCCESS);
  assert(n_devs == {devices});
"""

    checks = """\
  assert(strcmp(dev[{i}].coseType, "es256") == 0);
  assert(strcmp(dev[{i}].keyHandle, "{kh}") == 0);
  assert(strcmp(dev[{i}].publicKey, "{pk}") == 0);
  assert(strcmp(dev[{i}].attributes, "{attr}") == 0);
  assert(dev[{i}].old_format == {old});
"""

    end = """\
  free_devices(dev, n_devs);
"""

    code = ""
    free_block = ""

    code += start.format(authfile=filename, devices=len(credentials))
    for c, v in enumerate(credentials):
        code += checks.format(
            i=c, kh=v.keyhandle, pk=v.pubkey, attr=v.attributes, old=v.oldformat
        )

    code += end

    print(code)


def generate_credential(filename, mode, *args):
    command = [PUC, "-u@USERNAME@" if mode == "w" else "-n"]
    command.extend([x for x in args if x.strip() != ""])
    line = subprocess.check_output(command).decode("utf-8")
    with open(filename, mode) as handle:
        handle.write(line)

    matches = re.match(r"^.*?:(.*?),(.*?),es256,(.*)", line, re.M)
    return Credential(
        keyhandle=matches.group(1),
        pubkey=matches.group(2),
        attributes=matches.group(3),
        oldformat=0,
    )


# Single credentials
print("Generating single credentials", file=sys.stderr)

for (r, p, n, v) in itertools.product(resident, presence, pin, verification):
    filename = "credentials/new_" + r + p + v + n + ".cred.in"
    if not os.path.exists(filename):
        print("Generating " + filename, file=sys.stderr)
        generate_credential(filename, "w", r, p, v, n)
    credentials = read_credentials(filename)
    filename = os.path.splitext(filename)[0]
    print_test_case(filename, credentials)


# Double credentials
print("Generating double credentials", file=sys.stderr)

for (r, p, n, v) in itertools.product(resident, presence, pin, verification):
    filename = "credentials/new_double_" + r + p + v + n + ".cred.in"
    if not os.path.exists(filename):
        print("Generating " + filename, file=sys.stderr)
        generate_credential(filename, "w", r, p, v, n),
        generate_credential(filename, "a", r, p, v, n),
    credentials = read_credentials(filename)
    filename = os.path.splitext(filename)[0]
    print_test_case(filename, credentials)

# Mixed credentials
print("Mixed double credentials", file=sys.stderr)

for (p1, p2) in itertools.product(presence, presence):
    filename = "credentials/new_mixed_" + p1 + "1" + p2 + "2" + ".cred.in"
    if not os.path.exists(filename):
        print("Generating " + filename, file=sys.stderr)
        generate_credential(filename, "w", p1),
        generate_credential(filename, "a", p2),
    credentials = read_credentials(filename)
    filename = os.path.splitext(filename)[0]
    print_test_case(filename, credentials)