#!/usr/bin/env python3
"""Resolves each project's _templates/*.md against its _data.json and overwrites
the tracked *.md files with the result.

Why this exists: the legal documents repeat the same provider identity, hosting
entity, and sub-processor names/countries across several files — each document
phrases its surrounding table differently, so it's the *values*, not whole
blocks, that repeat. Before this script, changing e.g. the company address
meant editing every document by hand and risking them drifting apart.

The templates are the edit source; the tracked *.md files are a build output,
exactly like dist/legal-manifest.json is a build output of build-manifest.py.
Both are committed to git, so build-manifest.py's content_hash/version (which
hash the tracked *.md, not the template) keep meaning exactly what they did
before this script existed — and downstream consumers that read the tracked
H2W-Ticketing/*.md directly are unaffected, since they still see fully
resolved text, never a placeholder.

Placeholder syntax: {{ dotted.path }}, resolved against _data.json.

Missing data: a value of "-", "—" or "" in _data.json means "nincs ilyen adat" (pl. egyéni
vállalkozónak nincs cégjegyzékszáma). Such a value is never printed:
- a markdown table row ("| ... |") containing such a token is dropped entirely;
- an optional inline segment [[ ... ]] containing such a token is dropped (otherwise only
  its brackets are removed), e.g. "[[, nyilvántartási szám: {{ provider.registration_number }}]]". Deliberately
NOT used for numeric periods (30 nap, 8 nap, 99%, ...) that happen to repeat —
those repeat by coincidence of value, not by shared identity, and collapsing
them would risk an edit to one clause silently changing an unrelated one.

Usage:
    python3 scripts/render-templates.py           # resolve and overwrite
    python3 scripts/render-templates.py --check   # exit 1 on drift, write nothing
"""

import json
import re
import sys
from pathlib import Path

REPO_ROOT = Path(__file__).resolve().parent.parent
TOKEN_RE = re.compile(r"\{\{\s*([\w.]+)\s*\}\}")


def resolve_token(data: dict, dotted_path: str) -> str:
    value = data
    for part in dotted_path.split("."):
        value = value[part]
    return value


MISSING_VALUES = {"", "-", "—"}
OPTIONAL_RE = re.compile(r"\[\[(.*?)\]\]", re.DOTALL)


def _has_missing(text: str, data: dict) -> bool:
    return any(str(resolve_token(data, m.group(1))).strip() in MISSING_VALUES for m in TOKEN_RE.finditer(text))


def render(template: str, data: dict) -> str:
    # 1) opcionális szakaszok: hiányzó adattal együtt kimaradnak
    template = OPTIONAL_RE.sub(lambda m: "" if _has_missing(m.group(1), data) else m.group(1), template)
    # 2) táblázatsor hiányzó adattal: az egész sor kimarad
    lines = [
        line
        for line in template.split("\n")
        if not (line.lstrip().startswith("|") and _has_missing(line, data))
    ]
    return TOKEN_RE.sub(lambda m: resolve_token(data, m.group(1)), "\n".join(lines))


def main() -> None:
    check_only = "--check" in sys.argv
    drift = False

    for project_dir in sorted(REPO_ROOT.iterdir()):
        templates_dir = project_dir / "_templates"
        if not templates_dir.is_dir():
            continue

        data_path = project_dir / "_data.json"
        data = json.loads(data_path.read_text(encoding="utf-8"))

        for template_path in sorted(templates_dir.glob("*.md")):
            target_path = project_dir / template_path.name
            resolved = render(template_path.read_text(encoding="utf-8"), data)

            if check_only:
                current = target_path.read_text(encoding="utf-8") if target_path.exists() else None
                if current != resolved:
                    print(f"ELTÉRÉS: {target_path.relative_to(REPO_ROOT)}")
                    drift = True
                continue

            target_path.write_text(resolved, encoding="utf-8")
            print(f"Feloldva: {target_path.relative_to(REPO_ROOT)}")

    if check_only and drift:
        print("A sablonokból generált tartalom eltér a commitolt fájloktól — futtasd: python3 scripts/render-templates.py")
        sys.exit(1)


if __name__ == "__main__":
    main()