#!/usr/bin/env python
#

"""
paginate: Paginate Markdown file by inserting page breaks after output cells

Example:
   paginate < infile > outfile
"""

import os
import re
import sys

import gterm

usage = "usage: %prog file ..."

form_parser = gterm.FormParser(usage=usage, title="Paginate Markdown file", command="paginate")

START_FENCE_RE = re.compile(r"^```(expect|output)")
END_FENCE_RE = re.compile(r"^```\s*$")
IMAGE_RE = re.compile(r"^\s*!\[([^\]]*)\]\s*\[(expect|output)-([^\]]+)\]")

try:
    fenced = False
    page = True
    for line in sys.stdin.readlines():
        if fenced:
            if END_FENCE_RE.match(line):
                fenced = False
        elif START_FENCE_RE.match(line):
            fenced = True
            page = False
        elif IMAGE_RE.match(line):
            page = False
        elif not page and line.strip():
            # Non-fenced Non-blank non-image line
            sys.stdout.write("\n---\n\n")
            page = True
        sys.stdout.write(line)
except EOFError:
    pass
