#!/usr/bin/env python3
# Copyright (c) 2021 OK Ojisan(Takuya OKAHISA)
# Released under the MIT license
# http://opensource.org/licenses/mit-license.php
# hpp version 1.2

import os
import sys
import re
import html

def hpp(stream, n = 0, flags = None, defs = None):
    cmdname = os.path.basename(sys.argv[0])
    if n > 10:
        err = "{0}: 再帰の段数が 10 を超えました。".format(cmdname)
        print(err, file=sys.stderr)
        sys.exit(1)
    target = stream.name
    ls = os.linesep
    pairs = [x.split("=", 1) for x in sys.argv[1:]]
    if flags is None:
        flags = [x[0] for x in pairs if len(x) >= 1 and x[0] != ""]
    if defs is None:
        defs = [x for x in pairs if len(x) == 2 and x[0] != ""]
    do_print = True
    in_use = False
    esc = False
    stack = []
    useindent = ""
    retval = ""
    macro = ""
    param = ""
    value = ""
    content = ""
    lineno = 0
    for row in stream:
        lineno += 1
        strip = row.strip()
        indent = re.match("^(\s*)", row).group(1)
        if m := re.match("^<!--\$(\|?)include\s+(.+?)\s?-->$", strip):
            if do_print:
                if m.group(1) == "|": indent = ""
                filename = m.group(2)
                text = ""
                with rdopen(filename) as f:
                    text = hpp(f, n + 1, flags, defs)
                for line in text.splitlines():
                    output = indent + line + ls
                    if in_use:
                        value += line + ls
                    elif n == 0:
                        print(output, end="")
                    else:
                        retval += output
        elif m := re.match("^<!--\$ifdef\s+(.+?)\s?-->$", strip):
            stack.append(do_print)
            flag = m.group(1)
            do_print = do_print and any([f == flag for f in flags])
        elif m := re.match("^<!--\$ifndef\s+(.+?)\s?-->$", strip):
            stack.append(do_print)
            flag = m.group(1)
            do_print = do_print and not any([f == flag for f in flags])
        elif strip == "<!--$endif-->" or \
                re.match("^<!--\$endif\s+(.*?)\s?-->$", strip):
            do_print = stack.pop()
        elif strip == "<!--$else-->" or \
                re.match("^<!--\$else\s+(.*?)\s?-->$", strip):
            do_print = not do_print 
        elif m := re.match("^<!--\$(\|?)use\s+(.+?)\s?-->$", strip):
            if do_print and in_use:
                err1 = "{0}: {1}:{2}行目: ".format(cmdname, target, lineno)
                err2 = "use または def の中で use は使えません。"
                print(err1, file=sys.stderr, end="")
                print(err2, file=sys.stderr)
                sys.exit(1)
            if do_print:
                useindent = "" if m.group(1) == "|" else indent
                param = ""
                value = ""
                source = m.group(2)
                content = get_content(n, source, flags, defs)
                in_use = True
                esc = False
        elif m := re.match("^<!--\$sub\s+(.+?)\s?-->$", strip):
            if do_print and param != "":
                value = trimls(value)
                content = content.replace(param, value)
            if do_print:
                param = m.group(1)
                value = ""
                in_use = True
        elif re.match("^<!--\$enduse\s?-->$", strip):
            if do_print and param != "":
                value = trimls(value)
                content = content.replace(param, value)
            if do_print:
                if esc: content = html.escape(content)
                for line in content.splitlines():
                    output = useindent + line + ls
                    if n == 0:
                        print(output, end="")
                    else:
                        retval += output
                param = ""
                value = ""
                content = ""
                in_use = False
                esc = False
        elif m := re.match("^<!--\$(\|?)use(.)(.)(.+)-->$", strip):
            if do_print:
                if m.group(1) == "|": indent = ""
                sep1 = m.group(2)
                sep2 = m.group(3)
                subs = m.group(4).split(sep2)
                source = subs.pop(0)
                text = get_content(n, source, flags, defs)
                text = subst(text, subs, sep1, defs)
                for line in text.splitlines():
                    output = indent + line + ls
                    if in_use:
                        value += line + ls
                    elif n == 0:
                        print(output, end="")
                    else:
                        retval += output
        elif m := re.match("^<!--\$def\s+(.+?)\s+use\s+(.+?)\s?-->$", strip):
            if do_print and in_use:
                err1 = "{0}: {1}:{2}行目: ".format(cmdname, target, lineno)
                err2 = "use または def の中で def/use は使えません。"
                print(err1, file=sys.stderr, end="")
                print(err2, file=sys.stderr)
                sys.exit(1)
            if do_print:
                useindent = indent
                macro = m.group(1)
                param = ""
                value = ""
                source = m.group(2)
                content = get_content(n, source, flags, defs)
                in_use = True
                esc = False
        elif m := re.match("^<!--\$def\s+(.+?)\s+use(.)(.)(.+)-->$", strip):
            if do_print:
                name = m.group(1)
                sep1 = m.group(2)
                sep2 = m.group(3)
                subs = m.group(4).split(sep2)
                source = subs.pop(0)
                text = get_content(n, source, flags, defs)
                text = subst(text, subs, sep1, defs)
                defs.append([name, text])
                flags.append(name)
        elif m := re.match("^<!--\$def\s+(.+?)\s?-->$", strip):
            if do_print and in_use:
                err1 = "{0}: {1}:{2}行目: ".format(cmdname, target, lineno)
                err2 = "use または def の中で def は使えません。"
                print(err1, file=sys.stderr, end="")
                print(err2, file=sys.stderr)
                sys.exit(1)
            if do_print:
                useindent = indent
                macro = m.group(1)
                param = ""
                value = ""
                content = ""
                in_use = True
                esc = False
        elif re.match("^<!--\$enddef\s?-->$", strip):
            if do_print and in_use:
                value = trimls(value)
                if param != "": content = content.replace(param, value)
                if content != "": value = content
                if esc: value = html.escape(value)
                defs.append([macro, value])
                flags.append(macro)
                macro = ""
                param = ""
                value = ""
                content = ""
                in_use = False
                esc = False
        elif re.match("^<!--\$enddef\*\s?-->$", strip):
            if do_print and in_use:
                value = trimls(value)
                if param != "": content = content.replace(param, value)
                if content != "": value = content
                value = value.replace("<!==", "<!--")
                value = value.replace("==>", "-->")
                value = html.escape(value)
                defs.append([macro, value])
                flags.append(macro)
                macro = ""
                param = ""
                value = ""
                content = ""
                in_use = False
                esc = False
        elif m := re.match("^<!--\$def(.)(.)(.+)-->$", strip):
            if do_print:
                sep1 = m.group(1)
                sep2 = m.group(2)
                subs = m.group(3).split(sep2)
                for sub in subs:
                    x = sub.split(sep1, 1)
                    if len(x) >= 1 and x[0] != "": flags.append(x[0])
                    if len(x) == 2 and x[0] != "":
                        name = x[0]
                        val = replace_macro(x[1], defs)
                        defs.append([name, val])
        elif m := re.match("^<!--\$undef(.)(.+)-->$", strip):
            if do_print:
                sep = m.group(1)
                names = m.group(2).split(sep)
                for flag in names:
                    if flag == "": continue
                    while flag in flags: flags.remove(flag)
                    for i in range(len(defs))[::-1]:
                        if defs[i][0] == flag: defs.pop(i)
        elif re.match("^<!--\$esc\s?-->$", strip):
            if do_print: esc = True
        elif m := re.match("^<!--\$import\s+(.+?)\s?-->$", strip):
            if do_print:
                filename = m.group(1)
                with rdopen(filename) as f:
                    hpp(f, n + 1, flags, defs)
        elif re.match("^<!--\$\$$", strip):
            pass
        elif re.match("^\$\$-->$", strip):
            pass
        elif do_print:
            row = replace_macro(row, defs)
            if in_use:
                n1 = len(indent)
                n2 = len(useindent)
                if strip == "":
                    value += ls
                elif n1 < n2:
                    value += row
                else:
                    value += row[n2:]
            elif n == 0:
                print(row, end="")
            else:
                retval += row
    return retval

def get_content(n, name, flags, defs):
    cmdname = os.path.basename(sys.argv[0])
    if (name[0].isalnum()):
        with rdopen(name) as f:
            return trimls(hpp(f, n + 1, flags, defs))
    else:
        for x in defs:
            if x[0] == name: return x[1]
    err = "{0}: {1} は定義されていません。".format(cmdname, name)
    print(err, file=sys.stderr)
    sys.exit(1)

def trimls(text):
    if len(text) >= 1 and text[-1] == "\n": text = text[0:-1]
    if len(text) >= 1 and text[-1] == "\r": text = text[0:-1]
    return text

def subst(text, subs, sep, defs):
    for sub in subs:
        x = sub.split(sep, 1)
        if len(x) == 2 and x[0] != "":
            par = x[0]
            val = replace_macro(x[1], defs)
            text = text.replace(par, val)
    return text

def replace_macro(text, defs):
    for x in defs:
        text = text.replace(x[0], x[1])
    return text

def rdopen(filename):
    return open(filename, encoding = "utf-8")

def show_macro(macro, defs):
    for x in defs:
        if x[0] == macro: print(x[1], file=sys.stderr)

hpp(sys.stdin)