"""HTML views for the workflow policy and guardrail inventory (#646)."""

from __future__ import annotations

import html
import json

from webui.policy_inventory import PolicyEntry, PolicyInventorySnapshot


def _source_pointer(source) -> str:
    path = source.path
    if source.anchor:
        path = f"{path}#{source.anchor}"
    return (
        f"<li>{html.escape(source.label)} — "
        f"<code>{html.escape(path)}</code> "
        f"<span class='muted'>({html.escape(source.kind)})</span></li>"
    )


def _active_block(entry: PolicyEntry) -> str:
    if entry.error:
        return (
            "<p class='muted'><strong>Active value unavailable:</strong> "
            f"{html.escape(entry.error)}</p>"
        )
    if not entry.active:
        return "<p class='muted'>No live projection for this guardrail.</p>"
    pretty = json.dumps(entry.active, indent=2, sort_keys=True, default=str)
    return f"<pre class='prompt-text'>{html.escape(pretty)}</pre>"


def _diff_block(entry: PolicyEntry) -> str:
    if entry.diff is None:
        if entry.documented_default is None:
            return "<p class='muted'>Diff vs documented default: not feasible (no declared default).</p>"
        return "<p class='muted'>Diff vs documented default: unavailable.</p>"
    status = entry.diff.get("status", "unknown")
    badge = "badge-claimed" if status == "matches_documented_default" else "badge-blocked"
    rows = []
    for key, cell in (entry.diff.get("checked") or {}).items():
        marker = "✓" if cell.get("matches") else "✗"
        rows.append(
            "<tr>"
            f"<td><code>{html.escape(str(key))}</code></td>"
            f"<td><code>{html.escape(str(cell.get('expected')))}</code></td>"
            f"<td><code>{html.escape(str(cell.get('observed')))}</code></td>"
            f"<td>{marker}</td>"
            "</tr>"
        )
    table = ""
    if rows:
        table = (
            "<table class='detail'><thead><tr>"
            "<th>Key</th><th>Documented</th><th>Active</th><th>Match</th>"
            "</tr></thead><tbody>"
            f"{''.join(rows)}</tbody></table>"
        )
    return (
        f"<p class='meta'>Diff vs documented default: "
        f"<span class='badge {badge}'>{html.escape(status)}</span></p>"
        f"{table}"
    )


def _entry_card(entry: PolicyEntry) -> str:
    sources = "".join(_source_pointer(s) for s in entry.sources)
    return (
        "<div class='prompt-card'>"
        f"<h3>{html.escape(entry.title)} "
        f"<span class='badge'>{html.escape(entry.category)}</span></h3>"
        f"<p>{html.escape(entry.summary)}</p>"
        "<p class='meta'><strong>Source pointers</strong></p>"
        f"<ul>{sources}</ul>"
        "<p class='meta'><strong>Active configuration</strong></p>"
        f"{_active_block(entry)}"
        f"{_diff_block(entry)}"
        "</div>"
    )


def render_policy_page(snapshot: PolicyInventorySnapshot) -> str:
    categories = ", ".join(html.escape(c) for c in snapshot.categories) or "none"
    cards = "".join(_entry_card(e) for e in snapshot.entries)
    build_errors = ""
    if snapshot.build_errors:
        items = "".join(
            f"<li>{html.escape(err)}</li>" for err in snapshot.build_errors
        )
        build_errors = (
            "<div class='stub'><p><strong>Some guardrails could not be built:"
            f"</strong></p><ul>{items}</ul></div>"
        )
    return (
        "<h2>Workflow policy &amp; guardrails</h2>"
        f"<p class='muted'>{html.escape(snapshot.note)}</p>"
        f"<p class='meta'>Schema v{snapshot.schema_version} · "
        f"{len(snapshot.entries)} guardrails · categories: {categories}</p>"
        f"{build_errors}"
        f"{cards}"
        "<p class='muted'>This page is read-only. It reports enforced policy "
        "and never edits or weakens a gate. Secret values are redacted.</p>"
    )