#!/usr/bin/env python3
"""Render the data-driven sections of landing/index.html.

The fork feature list and the client comparison table used to be edited by
hand in two places per feature (matrix #11). They now live in landing/data/:

  features.json    - the "our fork adds" groups, one short line per feature
  comparison.json  - the client comparison table + its "reviewed" date

and the stylesheet lives in landing/style.css. It is inlined into index.html
rather than linked, because the LXC 139 deploy copies index.html only.

Run `python3 landing/build.py` after editing either file and commit the
regenerated index.html (LXC 139 serves the files as-is; there is no build step
there). `--check` exits 1 if index.html is out of date, for CI.

Only the text between `<!-- BEGIN:name -->` and `<!-- END:name -->` markers is
rewritten; everything else in index.html stays hand-edited.
"""
import json
import re
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parent
INDEX = ROOT / "index.html"
MARK = {"yes": "✓", "no": "✗", "part": "~"}


def render_features(groups):
    out = ['<div class="fork-features">']
    for g in groups:
        out.append('    <div class="fork-group">')
        out.append(f'        <h4>{g["title"]}</h4>')
        out.append("        <ul>")
        out.extend(f"            <li>{item}</li>" for item in g["items"])
        out.append("        </ul>")
        out.append("    </div>")
    out.append("</div>")
    return "\n".join(out)


def render_cell(cell, ours):
    cls = ' class="ours"' if ours else ""
    if "mark" in cell:
        inner = f'<span class="{cell["mark"]}">{MARK[cell["mark"]]}</span>'
    else:
        inner = cell["text"]
    if cell.get("note"):
        inner += f'<small>{cell["note"]}</small>'
    return f"<td{cls}>{inner}</td>"


def render_comparison(data):
    clients = data["clients"]
    cols = len(clients) + 1
    out = ["<table>", "    <thead>", "        <tr>", "            <th></th>"]
    for i, c in enumerate(clients):
        cls = ' class="ours"' if i == 0 else ""
        sub = f'<small>{c["sub"]}</small>' if c["sub"] else ""
        out.append(f'            <th{cls}>{c["name"]}{sub}</th>')
    out += ["        </tr>", "    </thead>", "    <tbody>"]
    for sec in data["sections"]:
        out.append(f'        <tr class="section-header"><td colspan="{cols}">{sec["title"]}</td></tr>')
        for row in sec["rows"]:
            if len(row["cells"]) != len(clients):
                sys.exit(f'comparison.json: "{row["feature"]}" has {len(row["cells"])} cells, expected {len(clients)}')
            out.append("        <tr>")
            out.append(f'            <td>{row["feature"]}</td>')
            out.extend(f"            {render_cell(c, i == 0)}" for i, c in enumerate(row["cells"]))
            out.append("        </tr>")
    out += ["    </tbody>", "</table>"]
    return "\n".join(out)


def replace_block(html, name, content):
    pattern = re.compile(
        rf"(?P<indent>[ \t]*)<!-- BEGIN:{name} -->.*?<!-- END:{name} -->", re.S
    )
    m = pattern.search(html)
    if not m:
        sys.exit(f"index.html: missing <!-- BEGIN:{name} --> / <!-- END:{name} --> markers")
    indent = m.group("indent")
    body = "\n".join(indent + line if line else line for line in content.split("\n"))
    block = f"{indent}<!-- BEGIN:{name} -->\n{body}\n{indent}<!-- END:{name} -->"
    return html[: m.start()] + block + html[m.end() :]


def main():
    features = json.loads((ROOT / "data" / "features.json").read_text(encoding="utf-8"))
    comparison = json.loads((ROOT / "data" / "comparison.json").read_text(encoding="utf-8"))
    css = (ROOT / "style.css").read_text(encoding="utf-8").rstrip("\n")
    html = INDEX.read_text(encoding="utf-8")
    styles = "<style>\n" + "\n".join("    " + line if line else line for line in css.split("\n")) + "\n</style>"
    new = replace_block(html, "styles", styles)
    new = replace_block(new, "features", render_features(features))
    new = replace_block(new, "comparison", render_comparison(comparison))
    new = replace_block(
        new, "reviewed", f'Client comparison last reviewed <time datetime="{comparison["reviewed"]}">{comparison["reviewed"]}</time>'
    )
    if "--check" in sys.argv:
        if new != html:
            sys.exit("landing/index.html is out of date: run python3 landing/build.py")
        print("landing/index.html is up to date")
        return
    INDEX.write_text(new, encoding="utf-8")
    print("wrote", INDEX)


if __name__ == "__main__":
    main()