"""Converter from CHANGELOG.md (Markdown) to HTML suitable for a mypy blog post. How to use: 1. Write release notes in CHANGELOG.md. 2. Make sure the heading for the next release is of form `## Mypy X.Y`. 2. Run `misc/gen_blog_post_html.py X.Y > target.html`. 4. Manually inspect and tweak the result. Notes: * There are some fragile assumptions. Double check the output. """ import argparse import html import os import re import sys def format_lists(h: str) -> str: a = h.splitlines() r = [] i = 0 bullets = ("- ", "* ", " * ") while i < len(a): if a[i].startswith(bullets): r.append("

") else: r.append(a[i]) i += 1 return "\n".join(r) def format_code(h: str) -> str: a = h.splitlines() r = [] i = 0 while i < len(a): if a[i].startswith(" ") or a[i].startswith("```"): indent = a[i].startswith(" ") language: str = "" if not indent: language = a[i][3:] i += 1 if language: r.append(f'
')
            else:
                r.append("
")
            while i < len(a) and (
                (indent and a[i].startswith("    ")) or (not indent and not a[i].startswith("```"))
            ):
                # Undo > and <
                line = a[i].replace(">", ">").replace("<", "<")
                if indent:
                    # Undo this extra level of indentation so it looks nice with
                    # syntax highlighting CSS.
                    line = line[4:]
                r.append(html.escape(line))
                i += 1
            r.append("
")
            if not indent and a[i].startswith("```"):
                i += 1
        else:
            r.append(a[i])
            i += 1
    formatted = "\n".join(r)
    # remove empty first line for code blocks
    return re.sub(r"]*)>\n", r"", formatted)


def convert(src: str) -> str:
    h = src

    # Replace < and >.
    h = re.sub(r"<", "<", h)
    h = re.sub(r">", ">", h)

    # Title
    h = re.sub(r"^## (Mypy [0-9.]+)", r"
\1 Released
", h, flags=re.MULTILINE)

    # Subheadings
    h = re.sub(r"\n### ([A-Z`].*)\n", r"\n
\1
\n", h)

    # Sub-subheadings
    h = re.sub(r"\n\*\*([A-Z_`].*)\*\*\n", r"\n
\1
\n", h)
    h = re.sub(r"\n`\*\*([A-Z_`].*)\*\*\n", r"\n
`\1
\n", h)

    # Translate `**`
    h = re.sub(r"`\*\*`", "**", h)

    # Paragraphs
    h = re.sub(r"\n\n([A-Z])", r"\n\n
\1", h)

    # Bullet lists
    h = format_lists(h)

    # Code blocks
    h = format_code(h)

    # Code fragments
    h = re.sub(r"``([^`]+)``", r"\1", h)
    h = re.sub(r"`([^`]+)`", r"\1", h)

    # Remove **** noise
    h = re.sub(r"\*\*\*\*", "", h)

    # Bold text
    h = re.sub(r"\*\*([A-Za-z].*?)\*\*", r" \1", h)

    # Emphasized text
    h = re.sub(r" \*([A-Za-z].*?)\*", r" \1", h)

    # Remove redundant PR links to avoid double links (they will be generated below)
    h = re.sub(r"\[(#[0-9]+)\]\(https://github.com/python/mypy/pull/[0-9]+/?\)", r"\1", h)

    # Issue and PR links
    h = re.sub(r"\((#[0-9]+)\) +\(([^)]+)\)", r"(\2, \1)", h)
    h = re.sub(
        r"fixes #([0-9]+)",
        r'fixes issue \1',
        h,
    )
    # Note the leading space to avoid stomping on strings that contain #\d in the middle (such as
    # links to PRs in other repos)
    h = re.sub(r" #([0-9]+)", r' PR \1', h)
    h = re.sub(r"\) \(PR", ", PR", h)

    # Markdown links
    h = re.sub(r"\[([^]]*)\]\(([^)]*)\)", r'\1', h)

    # Add random links in case they are missing
    h = re.sub(
        r"contributors to typeshed:",
        'contributors to typeshed:',
        h,
    )

    # Add top-level HTML tags and headers for syntax highlighting css/js.
    # We're configuring hljs to highlight python and bash code. We can remove
    # this configure call to make it try all the languages it supports.
    h = f"""





{h}

"""

    return h


def extract_version(src: str, version: str) -> str:
    a = src.splitlines()
    i = 0
    heading = f"## Mypy {version}"
    while i < len(a):
        if a[i].strip() == heading:
            break
        i += 1
    else:
        raise RuntimeError(f"Can't find heading {heading!r}")
    j = i + 1
    while not a[j].startswith("## "):
        j += 1
    return "\n".join(a[i:j])


def main() -> None:
    parser = argparse.ArgumentParser(
        description="Generate HTML release blog post based on CHANGELOG.md and write to stdout."
    )
    parser.add_argument("version", help="mypy version, in form X.Y or X.Y.Z")
    args = parser.parse_args()
    version: str = args.version
    if not re.match(r"[0-9]+(\.[0-9]+)+$", version):
        sys.exit(f"error: Version must be of form X.Y or X.Y.Z, not {version!r}")
    changelog_path = os.path.join(os.path.dirname(__file__), os.path.pardir, "CHANGELOG.md")
    src = open(changelog_path).read()
    src = extract_version(src, version)
    dst = convert(src)
    sys.stdout.write(dst)


if __name__ == "__main__":
    main()