#!/usr/bin/env python3
"""
build_index.py — generate INDEX.md from workspace manifests.

Walks the `vk-gramatvediba` workspace tree, reads every `uapf.yaml` and the
top-level `enterprise/enterprise.yaml`, groups packages by their declared
level (0–4), and emits a level-grouped index at the workspace root.

Per UAPF specification §01-concepts.md, levels are an aggregation and
governance scope only — directory structure must not encode them. Per
§04-folder-structure.md the SHOULD-recommended workspace layout is
`enterprise/` + `domains/` + `processes/` regardless of level. INDEX.md is
therefore a level-grouped *view* over a spec-conformant on-disk layout,
not an alternative layout.

Usage:   python3 tools/build-index/build_index.py
Dependencies: pyyaml.
"""
import glob
import os
import sys

try:
    import yaml
except ImportError:
    sys.exit("error: pyyaml is required  (pip install pyyaml)")


def find_workspace_root(start):
    """Walk up from `start` until a directory containing `enterprise/` is found."""
    d = os.path.abspath(start)
    while d != os.path.dirname(d):
        if os.path.isdir(os.path.join(d, "enterprise")) and \
           os.path.isdir(os.path.join(d, "processes")):
            return d
        d = os.path.dirname(d)
    sys.exit("error: not inside a UAPF workspace (no enterprise/ + processes/)")


def read_manifest(path):
    with open(path, encoding="utf-8") as fh:
        return yaml.safe_load(fh)


def short(s, n=160):
    if not s:
        return ""
    return s.split("\n")[0][:n]


LEVEL_TITLES = {
    0: "L0 — Enterprise process collection index",
    1: "L1 — Domain process collections",
    2: "L2 — End-to-end business processes",
    3: "L3 — Composed subprocesses / variants",
    4: "L4 — Atomic executable processes",
}


def collect(ws):
    pkgs = {0: [], 1: [], 2: [], 3: [], 4: []}
    ent_path = os.path.join(ws, "enterprise", "enterprise.yaml")
    if os.path.isfile(ent_path):
        m = read_manifest(ent_path)
        # L0 enterprise-index nests id/name/description under `enterprise:`
        ent = m.get("enterprise") or m
        pkgs[0].append({
            "id": ent.get("id", "?"),
            "name": ent.get("name", ""),
            "desc": short(ent.get("description", "")),
            "path": "enterprise/enterprise.yaml",
            "includes": [p.get("ref", "") for p in (m.get("packages") or [])],
            "cornerstones": {},
        })
    for pat in ("domains/*/uapf.yaml", "processes/*/uapf.yaml"):
        for p in sorted(glob.glob(os.path.join(ws, pat))):
            m = read_manifest(p)
            lvl = m.get("level")
            if lvl not in pkgs:
                continue
            pkgs[lvl].append({
                "id": m.get("id", "?"),
                "name": m.get("name", ""),
                "desc": short(m.get("description", "")),
                "path": os.path.relpath(os.path.dirname(p), ws) + "/",
                "includes": m.get("includes") or [],
                "cornerstones": m.get("cornerstones") or {},
            })
    return pkgs


def render(pkgs):
    L = []
    L.append("# `vk-gramatvediba` workspace index")
    L.append("")
    L.append("This index lists every package in the workspace grouped by UAPF")
    L.append("level (L0–L4). Per UAPF specification `§01-concepts.md`, levels")
    L.append("are an aggregation and governance scope only; per")
    L.append("`§04-folder-structure.md` the SHOULD-recommended workspace layout")
    L.append("is `enterprise/`, `domains/`, `processes/` regardless of level.")
    L.append("This file is therefore a level-grouped *view* over a")
    L.append("spec-conformant on-disk layout, not an alternative layout.")
    L.append("")
    L.append("Regenerate with `python3 tools/build-index/build_index.py`.")
    L.append("")

    total = sum(len(v) for v in pkgs.values())
    L.append(f"Total packages: **{total}** "
             "(L0: {0}, L1: {1}, L2: {2}, L3: {3}, L4: {4}).".format(
                 *(len(pkgs[i]) for i in range(5))))
    L.append("")

    for lvl in (0, 1, 2, 3, 4):
        L.append(f"## {LEVEL_TITLES[lvl]}")
        L.append("")
        items = pkgs[lvl]
        if not items:
            L.append("_(none)_")
            L.append("")
            continue

        if lvl == 0:
            L.append("| Package | Path | Description |")
            L.append("|---|---|---|")
            for e in items:
                desc = e["name"] or e["desc"] or "—"
                L.append(f"| `{e['id']}` | `{e['path']}` | {desc} |")
        elif lvl in (1, 2, 3):
            L.append("| Package | Path | Includes | Description |")
            L.append("|---|---|---|---|")
            for e in items:
                inc = ", ".join(f"`{i}`" for i in e["includes"]) or "_(none)_"
                desc = e["name"] or e["desc"] or "—"
                L.append(f"| `{e['id']}` | `{e['path']}` | {inc} | {desc} |")
        else:  # L4
            L.append("| Package | Path | Cornerstones | Description |")
            L.append("|---|---|---|---|")
            for e in items:
                cs = e["cornerstones"] or {}
                present = [k for k in ("bpmn", "dmn", "cmmn", "resources")
                           if cs.get(k)]
                cs_str = ", ".join(present) or "_(none)_"
                desc = e["name"] or e["desc"] or "—"
                L.append(f"| `{e['id']}` | `{e['path']}` | {cs_str} | {desc} |")
        L.append("")
    return "\n".join(L) + "\n"


def main():
    ws = find_workspace_root(os.path.dirname(os.path.abspath(__file__)))
    pkgs = collect(ws)
    text = render(pkgs)
    out = os.path.join(ws, "INDEX.md")
    with open(out, "w", encoding="utf-8") as fh:
        fh.write(text)
    print(f"wrote {out}  ({sum(len(v) for v in pkgs.values())} packages)")


if __name__ == "__main__":
    main()