#!/usr/bin/env python3
"""Generate the machine-readable OpenUP model intermediates from the markdown sources.

Transforms the approved OpenUP artifacts (never hand-edited exports):
  docs/openup/analysis-design/uc-realization-mapping.md  (§2 table)
  docs/openup/requirements/use-case-model.md             (canonical UC names)
into:
  docs/openup/model/exports/uc-realizations.json

The use-case-model.json intermediate is NOT produced here: the markdown does not
carry per-step actor tags, so a faithful transformation requires the EA session
(export-model.ps1) or staged decisions. See docs/openup/model/README.md.

Runs on the standard library only (Linux, no EA/COM required).
"""

import json
import re
import sys
from pathlib import Path

REPO_ROOT = Path(__file__).resolve().parents[2]
MAPPING_MD = REPO_ROOT / "docs/openup/analysis-design/uc-realization-mapping.md"
UC_MODEL_MD = REPO_ROOT / "docs/openup/requirements/use-case-model.md"
OUTPUT_JSON = REPO_ROOT / "docs/openup/model/exports/uc-realizations.json"

UC_ID_PATTERN = re.compile(r"^(UC-\d{2})\s*(.*)$")


def canonical_use_case_names() -> dict[str, str]:
    """UC id -> full use case name, from the use-case-model.md overview table."""
    names: dict[str, str] = {}
    for line in UC_MODEL_MD.read_text(encoding="utf-8").splitlines():
        cells = [cell.strip() for cell in line.strip().strip("|").split("|")]
        if len(cells) < 2:
            continue
        match = UC_ID_PATTERN.match(cells[0])
        if match:
            names[match.group(1)] = cells[1]
    if len(names) != 12:
        raise SystemExit(
            f"expected 12 use cases in {UC_MODEL_MD}, found {len(names)}"
        )
    return names


def split_table_row(line: str) -> list[str]:
    return [cell.strip() for cell in line.strip().strip("|").split("|")]


def is_table_row(line: str) -> bool:
    return line.strip().startswith("|") and line.strip().endswith("|")


def parse_realization_table(mapping_text: str) -> tuple[list[dict], dict[str, str]]:
    """Parse the §2 mapping table into per-UC realization entries.

    Returns (realizations, paragraphs) where paragraphs carries the verbatim
    cross-cutting and dependency-rule paragraphs that follow the table.
    """
    lines = mapping_text.splitlines()
    section_started = False
    realizations: list[dict] = []
    current: dict | None = None

    for index, line in enumerate(lines):
        if line.startswith("## 2. UC realization mapping"):
            section_started = True
            continue
        if not section_started:
            continue
        if line.startswith("## 3."):
            break
        if not is_table_row(line):
            continue
        cells = split_table_row(line)
        if cells[0] and set(cells[0]) <= {"-", " ", ":"}:
            continue
        if cells[0] in ("UC", "Analysis class"):
            continue

        uc_cell = cells[0]
        element = {
            # Emphasis markers are formatting, not content; element names are
            # identifiers (e.g. **AdventureService** -> AdventureService).
            # All other cells stay verbatim.
            "name": cells[1].replace("**", ""),
            "stereotype": cells[2],
            "designElement": cells[3],
            "notes": cells[4] if len(cells) > 4 else "",
        }
        id_match = UC_ID_PATTERN.match(uc_cell)
        if id_match:
            current = {"id": f"{id_match.group(1)} Realization", "useCaseId": id_match.group(1), "elements": [element]}
            realizations.append(current)
        elif uc_cell == "" and current is not None:
            current["elements"].append(element)
        else:
            raise SystemExit(f"unparseable mapping row {index + 1}: {line!r}")

    paragraphs = {}
    for paragraph_key, paragraph_prefix in (
        ("crossCutting", "Cross-cutting design elements"),
        ("dependencyRule", "Dependency rule check"),
    ):
        paragraphs[paragraph_key] = next(
            (line for line in lines if line.startswith(paragraph_prefix)), ""
        )
    return realizations, paragraphs


def build_payload() -> dict:
    canonical_names = canonical_use_case_names()
    realizations, paragraphs = parse_realization_table(
        MAPPING_MD.read_text(encoding="utf-8")
    )
    if len(realizations) != 12:
        raise SystemExit(
            f"expected 12 realizations in {MAPPING_MD}, found {len(realizations)}"
        )
    for realization in realizations:
        realization["useCase"] = canonical_names[realization.pop("useCaseId")]
    return {
        "exportedFrom": (
            "docs/openup/analysis-design/uc-realization-mapping.md §2, generated by "
            "scripts/openup/markdown-to-json.py — generated file, never hand-edit"
        ),
        "realizations": realizations,
        "crossCutting": paragraphs["crossCutting"],
        "dependencyRule": paragraphs["dependencyRule"],
    }


def main() -> int:
    payload = build_payload()
    OUTPUT_JSON.parent.mkdir(parents=True, exist_ok=True)
    OUTPUT_JSON.write_text(
        json.dumps(payload, indent=2, ensure_ascii=False) + "\n", encoding="utf-8"
    )
    element_count = sum(len(r["elements"]) for r in payload["realizations"])
    print(
        f"wrote {OUTPUT_JSON.relative_to(REPO_ROOT)}: "
        f"{len(payload['realizations'])} realizations, {element_count} elements"
    )
    return 0


if __name__ == "__main__":
    sys.exit(main())