#!/usr/bin/env python3

# makes the "database.h" (1st argument, $1) file from "database.h.in"
# (2nd argument, $2), setting various mask operation definitions
# according to the number of words implied by the value of TT_MAXTYPES
import re
import sys

database_h_in = open(sys.argv[1], encoding="utf8").read()

maxtypes_rx = re.compile(r"#define\s+TT_MAXTYPES\s+(\d+)")

match = maxtypes_rx.findall(database_h_in)
if len(match) == 0:
    print(
        f"Bad regular expression in {sys.argv[0]}: Cannot generate database/database.h!",
        file=sys.stderr,
    )
    exit(-1)

maxtypes = int(match[0])

# Find derived values from bits per word
# Note that bits-per-word should be determined from the compiler, but
# 32 bits per word has always been hardwired into magic.
#
bpw = 32
maskwords = (maxtypes + bpw - 1) // bpw

# Prepare Output String
out_string = database_h_in


def p(string):
    global out_string
    out_string += f"{string}"


# Generated macros
def add_generated_mask_macro(name, expression, *, connector=","):
    global maskwords

    p(f"#define {name} ( \\\n")
    for i in reversed(range(maskwords)):
        p(f"\t{expression.format(i=i)}")
        if i == 0:
            p(")\n\n")
        else:
            p(f"{connector} \\\n")


add_generated_mask_macro(
    "TTMaskZero(m)",
    "(m)->tt_words[{i}] = 0",
)
add_generated_mask_macro(
    "TTMaskIsZero(m)",
    "(m)->tt_words[{i}] == 0",
    connector=" &&",
)
add_generated_mask_macro(
    "TTMaskEqual(m, n)",
    "(m)->tt_words[{i}] == (n)->tt_words[{i}]",
    connector=" &&",
)
add_generated_mask_macro(
    "TTMaskIntersect(m, n)",
    "((m)->tt_words[{i}] & (n)->tt_words[{i}])",
    connector=" ||",
)
add_generated_mask_macro(
    "TTMaskCom(m)",
    "((m)->tt_words[{i}] = ~(m)->tt_words[{i}])",
)
add_generated_mask_macro(
    "TTMaskCom2(m, n)",
    "((m)->tt_words[{i}] = ~(n)->tt_words[{i}])",
)
add_generated_mask_macro(
    "TTMaskSetMask(m, n)",
    "((m)->tt_words[{i}] |= (n)->tt_words[{i}])",
)
add_generated_mask_macro(
    "TTMaskSetMask3(m, n, o)",
    "((m)->tt_words[{i}] |= (n)->tt_words[{i}] | (o)->tt_words[{i}])",
)
add_generated_mask_macro(
    "TTMaskAndMask(m, n)",
    "((m)->tt_words[{i}] &= (n)->tt_words[{i}])",
)
add_generated_mask_macro(
    "TTMaskAndMask3(m, n, o)",
    "((m)->tt_words[{i}] = (n)->tt_words[{i}] & (o)->tt_words[{i}])",
)
add_generated_mask_macro(
    "TTMaskClearMask(m, n)",
    "((m)->tt_words[{i}] &= ~(n)->tt_words[{i}])",
)
add_generated_mask_macro(
    "TTMaskClearMask3(m, n, o)",
    "((m)->tt_words[{i}] = (n)->tt_words[{i}] & ~(o)->tt_words[{i}])",
)

p("#endif /* _DATABASE_H */\n")

with open(sys.argv[2], "w", encoding="utf8") as f:
    f.write(out_string)