#!/usr/bin/env python3
"""
Generate the Markdown rulebook from rules.yaml (EV-008).

USAGE
    python3 generate_rulebook_md.py [output.md]

rules.yaml is the single source of truth. This script never edits it.
The output must never be edited by hand (EV-007).
"""
import os
import sys

import yaml

HERE = os.path.dirname(os.path.abspath(__file__))
SRC = os.path.join(HERE, "rules.yaml")
OUT = sys.argv[1] if len(sys.argv) > 1 else os.path.join(HERE, "PR_TBox_Rulebook.md")


def selfcheck(doc):
    """EV-011 and EV-012 applied to the rulebook itself."""
    problems = []
    for r in doc["rules"]:
        ctl = r.get("control") or {}
        if not ctl.get("tier"):
            problems.append("%s: no control tier (EV-012)" % r["id"])
        if r.get("severity") == "BLOCKING" and not ctl.get("executor"):
            problems.append("%s: BLOCKING without an executor (EV-011)" % r["id"])
        if r.get("category") not in doc["categories"]:
            problems.append("%s: unknown category" % r["id"])
    return problems


def flow(text):
    """Collapse a YAML folded scalar into a single paragraph."""
    return " ".join((text or "").split())


def joined(v):
    return ", ".join(v) if isinstance(v, list) else (v or "-")


def main():
    doc = yaml.safe_load(open(SRC, encoding="utf-8"))
    problems = selfcheck(doc)
    if problems:
        print("SELF-CHECK FAILED")
        for p in problems:
            print("  " + p)
        sys.exit(1)

    m, out = doc["meta"], []
    w = out.append

    w("# %s" % m["title"])
    w("")
    w("**Version %s** — %s — generated %s" % (m["version"], m["status"], m["date"]))
    w("")
    w("> Generated from `rules.yaml`. Do not edit this document: edit the source "
      "and regenerate (EV-007, EV-008).")
    w("")
    w("## Scope")
    w("")
    w(flow(m["scope"]))
    w("")
    w(flow(m["audience"]))
    w("")
    w("## Categories")
    w("")
    w("| Category | Subject | Rules |")
    w("|---|---|---|")
    for k, v in doc["categories"].items():
        n = sum(1 for r in doc["rules"] if r["category"] == k)
        w("| **%s** | %s | %d |" % (k, v["title"], n))
    w("")
    w("## Severity")
    w("")
    for k, v in doc["severity_model"].items():
        w("- **%s** — %s" % (k, flow(v)))
    w("")

    for cat, info in doc["categories"].items():
        w("---")
        w("")
        w("# %s — %s" % (cat, info["title"]))
        w("")
        w(flow(info["intent"]))
        w("")
        for r in [x for x in doc["rules"] if x["category"] == cat]:
            ctl = r.get("control") or {}
            w("## %s — %s" % (r["id"], r["title"]))
            w("")
            w("**Statement.** %s" % flow(r["statement"]))
            w("")
            w("| | |")
            w("|---|---|")
            w("| Severity | **%s** |" % r["severity"])
            w("| Applies to | %s |" % joined(r.get("scope")))
            w("| Enforced at | %s |" % joined(ctl.get("tier")))
            w("| Executor | `%s` |" % (ctl.get("executor") or "-"))
            w("| Procedure | %s |" % (ctl.get("procedure") or "_pending_"))
            if r.get("filiation"):
                w("| Related | %s |" % r["filiation"])
            w("")
            if r.get("rationale"):
                w("**Why.** %s" % flow(r["rationale"]))
                w("")
            if r.get("examples"):
                w("| From | To | Note |")
                w("|---|---|---|")
                for e in r["examples"]:
                    w("| %s | %s | %s |" % (e["from"], e["to"], e.get("note") or ""))
                w("")

    ab = doc["abstractness"]
    w("---")
    w("")
    w("# Annex A — Abstractness")
    w("")
    w("Applies TN-006 and TN-007 to the model. %d classes, of which **%d abstract** "
      "and **%d concrete**. Maintained with the model, not after it."
      % (len(ab), sum(1 for a in ab if a["is_abstract"]),
         sum(1 for a in ab if not a["is_abstract"])))
    w("")
    w("| Class | isAbstract | Note |")
    w("|---|---|---|")
    for a in ab:
        w("| `%s` | %s | %s |"
          % (a["term"], "**true**" if a["is_abstract"] else "false", a.get("note") or ""))
    w("")
    w("---")
    w("")
    w("# Annex B — Display")
    w("")
    w("Applies TN-011 and TN-022. The short label is what screens display and what "
      "relation names reuse; the acronym is a search key, never an identity.")
    w("")
    w("| IRI | rdfs:label | shortLabel | acronym | Note |")
    w("|---|---|---|---|---|")
    for d in doc["display"]:
        w("| `%s` | %s | %s | %s | %s |"
          % (d["iri"], d["label"], d.get("short_label") or "-",
             d.get("acronym") or "-", d.get("note") or ""))
    w("")

    open(OUT, "w", encoding="utf-8").write("\n".join(out))
    print("self-check passed: %d rules, every tier assigned, no blocking rule "
          "without an executor" % len(doc["rules"]))
    print("written: %s (%d lines)" % (OUT, len(out)))


if __name__ == "__main__":
    main()