# =============================================================================
# Projet : AIR — Accounting Intermediate Representation
# Auteur : Simon-Pierre Boucher
# Contact : contact@spboucher.ai
# Fichier : workspace.py
# Description : AIR home — a managed local data directory: ledger, archived documents, exports.
# =============================================================================
"""The AIR home: managed local data for standalone users.

Users without any third-party system keep everything in one directory:

    <home>/
    ├── meta.json         # company name, default policy set, created date
    ├── ledger.jsonl      # the hash-chained book of record
    ├── documents/        # every AIR document ever posted (content-addressed)
    └── exports/          # generated CSV/JSON exports and reports

Documents are archived content-addressed (sha256 prefix + original name), so
the exact input of every posting can be replayed later — pairing with the
ledger's idempotency keys and the compiler's determinism, the entire book of
record is reproducible from this directory alone.
"""
from __future__ import annotations

import hashlib
import json
from dataclasses import dataclass
from pathlib import Path

from kernel.ledger import Ledger

META_FILE = "meta.json"


class WorkspaceError(RuntimeError):
    pass


@dataclass
class Workspace:
    root: Path

    # -- lifecycle -----------------------------------------------------------
    @classmethod
    def init(
        cls,
        root: str | Path,
        *,
        name: str = "my-books",
        policies: str | None = None,
        created: str | None = None,
    ) -> "Workspace":
        root = Path(root)
        if (root / META_FILE).exists():
            raise WorkspaceError(f"workspace already initialized: {root}")
        (root / "documents").mkdir(parents=True, exist_ok=True)
        (root / "exports").mkdir(parents=True, exist_ok=True)
        meta = {
            "_author": "Simon-Pierre Boucher <contact@spboucher.ai>",
            "air_home_version": "1",
            "name": name,
            "policies": policies,
            "created": created,
        }
        (root / META_FILE).write_text(json.dumps(meta, indent=2), encoding="utf-8")
        (root / "ledger.jsonl").touch()
        return cls(root=root)

    @classmethod
    def open(cls, root: str | Path) -> "Workspace":
        root = Path(root)
        if not (root / META_FILE).exists():
            raise WorkspaceError(
                f"no AIR home at {root} — run: air init --home {root} "
                "--policies <policy-set.yaml>"
            )
        return cls(root=root)

    # -- accessors -------------------------------------------------------------
    @property
    def meta(self) -> dict:
        return json.loads((self.root / META_FILE).read_text(encoding="utf-8"))

    @property
    def ledger_path(self) -> Path:
        return self.root / "ledger.jsonl"

    @property
    def exports_dir(self) -> Path:
        return self.root / "exports"

    def ledger(self) -> Ledger:
        return Ledger(path=self.ledger_path)

    def default_policies(self) -> str | None:
        return self.meta.get("policies")

    # -- data management -----------------------------------------------------------
    def archive_document(self, path: str | Path) -> Path:
        """Store a posted AIR document content-addressed; idempotent."""
        path = Path(path)
        content = path.read_bytes()
        digest = hashlib.sha256(content).hexdigest()[:12]
        target = self.root / "documents" / f"{digest}_{path.name}"
        if not target.exists():
            target.write_bytes(content)
        return target

    def save_export(self, filename: str, content: str) -> Path:
        target = self.exports_dir / filename
        target.write_text(content, encoding="utf-8")
        return target

    def status(self) -> dict:
        ledger = self.ledger()
        documents = sorted((self.root / "documents").glob("*"))
        exports = sorted(self.exports_dir.glob("*"))
        return {
            "home": str(self.root),
            "name": self.meta.get("name"),
            "policies": self.meta.get("policies"),
            "entries": len(ledger.entries),
            "chain_valid": ledger.verify_chain(),
            "documents_archived": len(documents),
            "exports": len(exports),
        }