"""Session-memory sweep entrypoint (design §7; T06).

One sweep: discover (per enabled source) -> normalize (adapter) -> store ->
digest -> retention-evict. Idempotent and re-runnable; intended to be triggered
on the configured cadence (``/schedule`` daily/weekly) or by an agent hook.

Usage:
    python -m session_memory.ingest [--config PATH] [--once] [--dry-run]
"""

from __future__ import annotations

import argparse
import glob
import os
import sys
import tomllib
from dataclasses import dataclass, field
from typing import Any

from .adapters import claude as claude_adapter
from .core import digest as digest_mod
from .core.cursor import Cursors
from .core.retention import RetentionConfig, sweep as retention_sweep
from .core.store import Store

# adapter dispatch by source name
_ADAPTERS = {"claude": claude_adapter.parse_session}


@dataclass
class SweepResult:
    discovered: int = 0
    ingested: int = 0
    skipped_unchanged: int = 0
    analyzed: int = 0
    warnings: list[str] = field(default_factory=list)
    retention: Any = None


def _expand(p: str) -> str:
    return os.path.expanduser(p)


def load_config(path: str) -> dict[str, Any]:
    with open(path, "rb") as f:
        return tomllib.load(f)


def run_sweep(config: dict[str, Any], *, dry_run: bool = False) -> SweepResult:
    store_cfg = config.get("store", {})
    ret_cfg = config.get("retention", {})
    repo_map = config.get("repo_domain_map", {})
    res = SweepResult()

    # In dry-run we only discover + parse: no store is created or written.
    store = None if dry_run else Store(_expand(store_cfg["db_path"]), _expand(store_cfg["blob_dir"]))
    cursors = Cursors(_expand(store_cfg["cursor"]))

    for name, src in config.get("sources", {}).items():
        if not src.get("enabled"):
            continue
        parse = _ADAPTERS.get(name)
        if parse is None:
            res.warnings.append(f"no adapter for source {name!r} (Phase 1)")
            continue
        root = _expand(src["root"])
        for fp in sorted(glob.glob(os.path.join(root, src["glob"]))):
            res.discovered += 1
            if not cursors.is_changed(fp):
                res.skipped_unchanged += 1
                continue
            try:
                bundle = parse(fp, repo_map)
            except Exception as e:  # one bad file must not abort the sweep
                res.warnings.append(f"parse failed {fp}: {e}")
                continue
            if bundle is None:
                cursors.mark(fp)
                continue
            if not dry_run:
                store.ingest(bundle)
                digest_mod.analyze(store, bundle.session.session_uid)
                res.analyzed += 1
            res.ingested += 1
            cursors.mark(fp)

    if not dry_run and store is not None:
        cursors.save()
        rc = RetentionConfig(
            raw_soft_cap_bytes=int(ret_cfg.get("raw_soft_cap_bytes", RetentionConfig.raw_soft_cap_bytes)),
            raw_hard_cap_bytes=int(ret_cfg.get("raw_hard_cap_bytes", RetentionConfig.raw_hard_cap_bytes)),
            raw_max_age_days=int(ret_cfg.get("raw_max_age_days", RetentionConfig.raw_max_age_days)),
            distilled_cap_bytes=int(ret_cfg.get("distilled_cap_bytes", RetentionConfig.distilled_cap_bytes)),
        )
        res.retention = retention_sweep(store, rc, analyze_fn=digest_mod.analyze)
        res.warnings.extend(res.retention.warnings)

    if store is not None:
        store.close()
    return res


def main(argv: list[str] | None = None) -> int:
    here = os.path.dirname(os.path.abspath(__file__))
    ap = argparse.ArgumentParser(description="Run one coding-session-memory sweep.")
    ap.add_argument("--config", default=os.path.join(here, "config.toml"))
    ap.add_argument("--dry-run", action="store_true", help="discover + parse, but do not write or evict")
    ap.add_argument("--once", action="store_true", help="(default) run a single sweep")
    args = ap.parse_args(argv)

    config = load_config(args.config)
    res = run_sweep(config, dry_run=args.dry_run)

    print(f"discovered={res.discovered} ingested={res.ingested} "
          f"skipped_unchanged={res.skipped_unchanged} analyzed={res.analyzed}")
    if res.retention is not None:
        r = res.retention
        print(f"retention: freed={r.bytes_freed}B final_usage={r.final_usage_bytes}B "
              f"backstop={len(r.backstop_evicted)} budget={len(r.budget_evicted)} "
              f"overflow_analyzed={len(r.overflow_analyzed)} data_loss={len(r.overflow_data_loss)}")
    for w in res.warnings:
        print(f"  WARN: {w}", file=sys.stderr)
    return 0


if __name__ == "__main__":
    raise SystemExit(main())