#!/usr/bin/env python

"""
"**Pycco**" is a Python port of [Docco](http://jashkenas.github.com/docco/):
the original quick-and-dirty, hundred-line-long, literate-programming-style
documentation generator. It produces HTML that displays your comments
alongside your code. Comments are passed through
[Markdown](http://daringfireball.net/projects/markdown/syntax) and
[SmartyPants](http://daringfireball.net/projects/smartypants), while code is
passed through [Pygments](http://pygments.org/) for syntax highlighting.
This page is the result of running Pycco against its own source file.

If you install Pycco, you can run it from the command-line:

    pycco src/*.py

This will generate linked HTML documentation for the named source files,
saving it into a `docs` folder by default.

The [source for Pycco](https://github.com/fitzgen/pycco) is available on GitHub,
and released under the MIT license.

To install Pycco, simply

    pip install pycco

Or, to install the latest source

    git clone git://github.com/fitzgen/pycco.git
    cd pycco
    python setup.py install
"""

# === Main Documentation Generation Functions ===

def generate_documentation(source, outdir=None, preserve_paths=True,
                           language=None):
    """
    Generate the documentation for a source file by reading it in, splitting it
    up into comment/code sections, highlighting them for the appropriate
    language, and merging them into an HTML template.
    """

    if not outdir:
        raise TypeError("Missing the required 'outdir' keyword argument.")
    code = open(source, "r").read()
    language = get_language(source, code, language=language)
    sections = parse(source, code, language)
    highlight(source, sections, language, preserve_paths=preserve_paths, outdir=outdir)
    return generate_html(source, sections, preserve_paths=preserve_paths, outdir=outdir)

def parse(source, code, language):
    """
    Given a string of source code, parse out each comment and the code that
    follows it, and create an individual **section** for it.
    Sections take the form:

        { "docs_text": ...,
          "docs_html": ...,
          "code_text": ...,
          "code_html": ...,
          "num":       ...
        }
    """

    lines = code.split("\n")
    sections = []
    has_code = docs_text = code_text = ""

    if lines[0].startswith("#!"):
        lines.pop(0)

    if language["name"] == "python":
        for linenum, line in enumerate(lines[:2]):
            if re.search(r'coding[:=]\s*([-\w.]+)', lines[linenum]):
                lines.pop(linenum)
                break


    def save(docs, code):
        if docs or code:
            sections.append({
                "docs_text": docs,
                "code_text": code
            })

    # Setup the variables to get ready to check for multiline comments
    multi_line = False
    multi_line_delimiters = [language.get("multistart"), language.get("multiend")]

    for line in lines:

        # Only go into multiline comments section when one of the delimiters is
        # found to be at the start of a line
        if all(multi_line_delimiters) and any([line.lstrip().startswith(delim) or line.rstrip().endswith(delim) for delim in multi_line_delimiters]):
            if not multi_line:
                multi_line = True

            else:
                multi_line = False

            if (multi_line
               and line.strip().endswith(language.get("multiend"))
               and len(line.strip()) > len(language.get("multiend"))):
                multi_line = False

            # Get rid of the delimiters so that they aren't in the final docs
            line = line.replace(language["multistart"], '')
            line = line.replace(language["multiend"], '')
            docs_text += line.strip() + '\n'
            indent_level = re.match("\s*", line).group(0)

            if has_code and docs_text.strip():
                save(docs_text, code_text[:-1])
                code_text = code_text.split('\n')[-1]
                has_code = docs_text = ''

        elif multi_line:
            # Remove leading spaces
            if re.match(r' {%d}' % len(indent_level), line):
                docs_text += line[len(indent_level):] + '\n'
            else:
                docs_text += line + '\n'

        elif re.match(language["comment_matcher"], line):
            if has_code:
                save(docs_text, code_text)
                has_code = docs_text = code_text = ''
            docs_text += re.sub(language["comment_matcher"], "", line) + "\n"

        else:
            if code_text and any([line.lstrip().startswith(x) for x in ['class ', 'def ', '@']]):
                if not code_text.lstrip().startswith("@"):
                    save(docs_text, code_text)
                    code_text = has_code = docs_text = ''

            has_code = True
            code_text += line + '\n'


    save(docs_text, code_text)

    return sections

# === Preprocessing the comments ===

def preprocess(comment, section_nr, preserve_paths=True, outdir=None):
    """
    Add cross-references before having the text processed by markdown.  It's
    possible to reference another file, like this : `[[main.py]]` which renders
    [[main.py]]. You can also reference a specific section of another file, like
    this: `[[main.py#highlighting-the-source-code]]` which renders as
    [[main.py#highlighting-the-source-code]]. Sections have to be manually
    declared; they are written on a single line, and surrounded by equals signs:
    `=== like this ===`
    """

    if not outdir:
        raise TypeError("Missing the required 'outdir' keyword argument.")
    def sanitize_section_name(name):
        return "-".join(name.lower().strip().split(" "))

    def replace_crossref(match):
        # Check if the match contains an anchor
        if '#' in match.group(1):
            name, anchor = match.group(1).split('#')
            return " [%s](%s#%s)" % (name,
                                     path.basename(destination(name,
                                                               preserve_paths=preserve_paths,
                                                               outdir=outdir)),
                                     anchor)

        else:
            return " [%s](%s)" % (match.group(1),
                                  path.basename(destination(match.group(1),
                                                            preserve_paths=preserve_paths,
                                                            outdir=outdir)))

    def replace_section_name(match):
        return '%(lvl)s <span id="%(id)s" href="%(id)s">%(name)s</span>' % {
            "lvl"  : re.sub('=', '#', match.group(1)),
            "id"   : sanitize_section_name(match.group(2)),
            "name" : match.group(2)
        }

    comment = re.sub('^([=]+)([^=]+)[=]*\s*$', replace_section_name, comment)
    comment = re.sub('[^`]\[\[(.+?)\]\]', replace_crossref, comment)

    return comment

# === Highlighting the source code ===

def highlight(source, sections, language, preserve_paths=True, outdir=None):
    """
    Highlights a single chunk of code using the **Pygments** module, and runs
    the text of its corresponding comment through **Markdown**.

    We process the entire file in a single call to Pygments by inserting little
    marker comments between each section and then splitting the result string
    wherever our markers occur.
    """

    if not outdir:
        raise TypeError("Missing the required 'outdir' keyword argument.")

    output = pygments.highlight(language["divider_text"].join(section["code_text"].rstrip() for section in sections),
                                language["lexer"],
                                formatters.get_formatter_by_name("html"))

    output = output.replace(highlight_start, "").replace(highlight_end, "")
    fragments = re.split(language["divider_html"], output)
    for i, section in enumerate(sections):
        section["code_html"] = highlight_start + shift(fragments, "") + highlight_end
        try:
            docs_text = unicode(section["docs_text"])
        except UnicodeError:
            docs_text = unicode(section["docs_text"].decode('utf-8'))
        section["docs_html"] = markdown(preprocess(docs_text,
                                                   i,
                                                   preserve_paths=preserve_paths,
                                                   outdir=outdir))
        section["num"] = i

# === HTML Code generation ===

def generate_html(source, sections, preserve_paths=True, outdir=None):
    """
    Once all of the code is finished highlighting, we can generate the HTML file
    and write out the documentation. Pass the completed sections into the
    template found in `resources/pycco.html`.

    Pystache will attempt to recursively render context variables, so we must
    replace any occurences of `{{`, which is valid in some languages, with a
    "unique enough" identifier before rendering, and then post-process the
    rendered template and change the identifier back to `{{`.
    """

    if not outdir:
        raise TypeError("Missing the required 'outdir' keyword argument")
    title = path.basename(source)
    dest = destination(source, preserve_paths=preserve_paths, outdir=outdir)
    csspath = path.relpath(path.join(outdir, "pycco.css"), path.split(dest)[0])

    for sect in sections:
        sect["code_html"] = re.sub(r"\{\{", r"__DOUBLE_OPEN_STACHE__", sect["code_html"])

    rendered = pycco_template({
        "title"       : title,
        "stylesheet"  : csspath,
        "sections"    : sections,
        "source"      : source,
        "path"        : path,
        "destination" : destination
    })

    return re.sub(r"__DOUBLE_OPEN_STACHE__", "{{", rendered).encode("utf-8")

# === Helpers & Setup ===

# This module contains all of our static resources.
import pycco_resources

# Import our external dependencies.
import optparse
import os
import pygments
import pystache
import re
import sys
import time
from markdown import markdown
from os import path
from pygments import lexers, formatters

# A list of the languages that Pycco supports, mapping the file extension to
# the name of the Pygments lexer and the symbol that indicates a comment. To
# add another language to Pycco's repertoire, add it here.
languages = {
    ".coffee": { "name": "coffee-script", "symbol": "#",
        "multistart": '###', "multiend": '###' },

    ".pl":  { "name": "perl", "symbol": "#" },

    ".sql": { "name": "sql", "symbol": "--" },

    ".c":   { "name": "c", "symbol": "//"},

    ".cpp": { "name": "cpp", "symbol": "//"},

    ".js": { "name": "javascript", "symbol": "//",
        "multistart": "/*", "multiend": "*/"},

    ".rb": { "name": "ruby", "symbol": "#",
        "multistart": "=begin", "multiend": "=end"},

    ".py": { "name": "python", "symbol": "#",
        "multistart": '"""', "multiend": '"""' },