# Copyright (c) 2016 CEF Python, see the Authors file.
# All rights reserved. Licensed under BSD 3-clause license.
# Project website: https://github.com/cztomczak/cefpython

"""Create Table of contents (TOC) for a single .md file or for a directory.

Usage:
 toc.py FILE
 toc.py DIR

To ignore file when generating TOC, put an empty line just before H1.
"""

import os
import sys
import re
import glob

API_DIR = os.path.join(os.path.dirname(__file__), "..", "api")


def main():
 """Main entry point."""
 if len(sys.argv) == 1:
 sys.argv.append(API_DIR)
 if (len(sys.argv) == 1 or
 "-h" in sys.argv or
 "--help" in sys.argv or
 "/?" in sys.argv):
 print(__doc__.strip())
 sys.exit(0)
 arg1 = sys.argv[1]
 if os.path.isdir(arg1):
 (modified, warnings) = toc_dir(arg1)
 if modified:
 print("Done")
 else:
 print("No changes to TOCs. Files not modified.")
 else:
 (modified, warnings) = toc_file(arg1)
 if modified:
 print("Done")
 else:
 print("No changes to TOC. File not modified.")
 if warnings:
 print("Warnings: "+str(warnings))


def toc_file(file_):
 """A single file was passed to doctoc. Return bool whether modified
 and the number of warnings."""
 with open(file_, "rb") as fo:
 orig_contents = fo.read().decode("utf-8", "ignore")
 # Fix new lines just in case. Not using Python's "rU",
 # it is causing strange issues.
 orig_contents = re.sub(r"(\r\n|\r|\n)", os.linesep, orig_contents)
 (tocsize, contents, warnings) = create_toc(orig_contents, file_)
 if contents != orig_contents:
 with open(file_, "wb") as fo:
 fo.write(contents.encode("utf-8"))
 tocsize_str = ("TOC size: "+str(tocsize) if tocsize
 else "TOC removed")
 print("Modified: "+file_+" ("+tocsize_str+")")
 return True, warnings
 else:
 return False, warnings


def toc_dir(dir_):
 """A directory was passed to doctoc. Return bool whether any file was
 modified and the number of warnings."""
 files = glob.glob(os.path.join(dir_, "*.md"))
 modified_any = False
 warnings = 0
 for file_ in files:
 if "API-categories.md" in file_ or "API-index.md" in file_:
 continue
 (modified, warnings) = toc_file(file_)
 if not modified_any:
 modified_any = True if modified else False
 return modified_any, warnings


def create_toc(contents, file_):
 """Create or modify TOC for the document contents."""
 match = re.search(r"Table of contents:%s(\s*\* \[[^\]]+\]\([^)]+\)%s){2,}"
 % (os.linesep, os.linesep), contents)
 oldtoc = match.group(0) if match else None
 (tocsize, toc, warnings) = parse_headings(contents, file_)
 if oldtoc:
 if not toc:
 # If toc removed need to remove an additional new lines
 # that was inserted after toc.
 contents = contents.replace(oldtoc+os.linesep, toc)
 else:
 contents = contents.replace(oldtoc, toc)
 elif tocsize:
 # Insert after H1, but if there is text directly after H1
 # then insert after that text.
 first_line = False
 if not re.search(r"^#\s+", contents):
 print("WARNING: missing H1 on first line. Ignoring file: "+file_)
 return 0, contents, warnings+1
 lines = contents.splitlines()
 contents = ""
 toc_inserted = False
 for line in lines:
 if not first_line:
 first_line = True
 else:
 if not toc_inserted and re.search(r"^(##|###)", line):
 contents = contents[0:-len(os.linesep)]
 contents += os.linesep + toc + os.linesep + os.linesep
 toc_inserted = True
 contents += line + os.linesep
 # Special case for README.md - remove Quick Links toc for subheadings
 re_find = (r" \* \[Docs\]\(#docs\)[\r\n]+"
 r" \* \[API categories\]\(#api-categories\)[\r\n]+"
 r" \* \[API index\]\(#api-index\)\r?\n?")
 contents = re.sub(re_find, "", contents)
 return tocsize, contents, warnings


def parse_headings(raw_contents, file_):
 """Parse contents looking for headings. Return a tuple with number
 of TOC elements, the TOC fragment and the number of warnings."""
 # Remove code blocks
 parsable_contents = re.sub(r"```[\s\S]+?```", "", raw_contents)
 # Parse H1,H2,H3
 headings = re.findall(r"^(#|##|###)\s+(.*)", parsable_contents,
 re.MULTILINE)
 toc = "Table of contents:" + os.linesep
 tocsize = 0
 warnings = 0
 count_h1 = 0
 count_h2 = 0
 for heading in headings:
 level = heading[0]
 level = (1 if level == "#" else
 2 if level == "##" else
 3 if level == "###" else None)
 assert level is not None
 title = heading[1].strip()
 if level == 1:
 count_h1 += 1
 if count_h1 > 1:
 warnings += 1
 print("WARNING: found more than one H1 in "+file_)
 continue
 if level == 2:
 count_h2 += 1
 hash_ = headinghash(title)
 indent = ""
 if level == 3:
 if count_h2:
 # If there was no H2 yet then H3 shouldn't have indent.
 indent = " " * 2
 toc += indent + "* [%s](#%s)" % (title, hash_) + os.linesep
 tocsize += 1
 if tocsize <= 1:
 # If there is only one H2/H3 heading do not create TOC.
 toc = ""
 tocsize = 0
 return tocsize, toc, warnings


def headinghash(title):
 """Get a link hash for a heading H1,H2,H3."""
 hash_ = title.lower()
 hash_ = hash_.replace(" - ", "specialcase1")
 hash_ = hash_.replace(" / ", "specialcase2")
 hash_ = re.sub(r"[^a-z0-9_\- ]+", r"", hash_)
 hash_ = hash_.replace(" ", "-")
 hash_ = re.sub(r"[-]+", r"-", hash_)
 hash_ = re.sub(r"-$", r"", hash_)
 hash_ = hash_.replace("specialcase1", "---")
 hash_ = hash_.replace("specialcase2", "--")
 return hash_


if __name__ == "__main__":
 main()