"""Offline: is the media loss age-based, source-based, or neither?

Answers the question the 403s raised — do I have to export within N days? —
from the exports already on disk. No API calls, no token, nothing to expire.

It works because the renderer records the outcome of every image in the
Markdown itself:

    ![user_upload](media/file_x.png)                 ← downloaded, still alive
    > 🖼️ **Image attached** — `sediment://file_y`
      (user_upload, content not preserved…)          ← dead or never fetched

and the conversation's date is in its filename (YYYY-MM-DD_slug_id.md). So
grouping outcomes by month and by source distinguishes the hypotheses:

  * Age-based expiry  → old months all-dead, recent months all-alive, with a
                        clean cutoff between them.
  * Source-based      → user_upload dies while model_generated survives at
                        the same age.
  * Neither           → deaths scattered across months, or concentrated in a
                        few conversations while their neighbours survive.

IMPORTANT — what "saved" does and does not mean. It means the image was
downloaded by *some* run at *some* point, not that ChatGPT still holds it. An
image captured in June looks saved forever after, even if it died in July. So
a month with no losses shows the exports were timely; it cannot show the
assets survived. Use probe_survival_by_month.py to ask the API what is still
live today. The one signal here that is immune to this confound is a single
conversation that both kept and lost images: same age, same chat, opposite
outcomes means the cause is per-asset, not retention.

Run from the project root:

    python tools/analyze_media_age.py
"""

import os
import re
import sys
from collections import defaultdict
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parent.parent))

from dotenv import load_dotenv

load_dotenv()

SAVED_RE = re.compile(r"!\[([^\]]*)\]\((media/[^)]+)\)")
DEAD_RE = re.compile(r"🖼️ \*\*Image attached\*\* — `([^`]+)`\s*\(([^)]*)\)")
DATE_RE = re.compile(r"(\d{4}-\d{2}-\d{2})_")


def main() -> None:
    export_dir = Path(os.getenv("EXPORT_DIR", "./exports")).expanduser()
    if not export_dir.is_dir():
        print(f"exports dir not found: {export_dir}")
        return

    # month → source → {"saved": n, "dead": n}
    stats: dict[str, dict[str, dict[str, int]]] = defaultdict(
        lambda: defaultdict(lambda: {"saved": 0, "dead": 0})
    )
    # conversations that lost at least one image
    losses: dict[str, dict[str, int]] = defaultdict(lambda: {"saved": 0, "dead": 0})
    oldest_saved: dict[str, str] = {}
    newest_dead: dict[str, str] = {}
    oldest_dead: dict[str, str] = {}

    for md in export_dir.rglob("*.md"):
        date_match = DATE_RE.search(md.name)
        if not date_match:
            continue
        date = date_match.group(1)
        month = date[:7]
        try:
            text = md.read_text(encoding="utf-8", errors="replace")
        except OSError:
            continue

        conv_key = f"{date}  {md.stem}"

        for source, _path in SAVED_RE.findall(text):
            source = source or "unknown"
            stats[month][source]["saved"] += 1
            losses[conv_key]["saved"] += 1
            if source not in oldest_saved or date < oldest_saved[source]:
                oldest_saved[source] = date

        for _ref, meta in DEAD_RE.findall(text):
            source = meta.split(",")[0].strip() or "unknown"
            stats[month][source]["dead"] += 1
            losses[conv_key]["dead"] += 1
            if source not in newest_dead or date > newest_dead[source]:
                newest_dead[source] = date
            if source not in oldest_dead or date < oldest_dead[source]:
                oldest_dead[source] = date

    if not stats:
        print(f"no dated conversations with images found under {export_dir}")
        return

    sources = sorted({s for m in stats.values() for s in m})

    print("=" * 78)
    print("Image outcomes by conversation month")
    print("=" * 78)
    header = f"{'month':<9}"
    for source in sources:
        header += f"  {source[:16]:>16} (saved/dead)"
    print(header)
    for month in sorted(stats):
        row = f"{month:<9}"
        for source in sources:
            cell = stats[month].get(source, {"saved": 0, "dead": 0})
            if cell["saved"] or cell["dead"]:
                row += f"  {cell['saved']:>8} / {cell['dead']:<17}"
            else:
                row += f"  {'—':>8}   {'':<17}"
        print(row)

    print()
    print("=" * 78)
    print("The age question")
    print("=" * 78)
    for source in sources:
        old_s = oldest_saved.get(source)
        old_d = oldest_dead.get(source)
        new_d = newest_dead.get(source)
        print(f"  {source}:")
        print(f"      oldest still downloadable : {old_s or '—'}")
        print(f"      dead range                : {old_d or '—'} … {new_d or '—'}")
        if old_s and new_d and old_s < new_d:
            print(
                f"      → an asset from {old_s} was captured while one from "
                f"{new_d} was not."
            )
            print(
                "        This does NOT disprove expiry: 'captured' means some "
                "run got it in time,"
            )
            print(
                "        not that it is still on ChatGPT today. Run "
                "probe_survival_by_month.py to tell"
            )
            print("        those apart.")
        elif old_s and old_d and old_s > old_d:
            print(
                f"      → everything lost is older than everything captured "
                f"(cutoff between {old_d} and {old_s}): consistent with expiry."
            )
    print()

    print("=" * 78)
    print("Conversations that lost images (clustering check)")
    print("=" * 78)
    lossy = {k: v for k, v in losses.items() if v["dead"]}
    for conv, counts in sorted(lossy.items()):
        print(f"  {conv[:66]:<66} saved={counts['saved']:<4} dead={counts['dead']}")
    total_dead = sum(v["dead"] for v in lossy.values())
    print()
    print(f"  {len(lossy)} conversation(s) affected, {total_dead} image(s) lost")
    mixed = [k for k, v in lossy.items() if v["saved"]]
    if mixed:
        print(
            f"  {len(mixed)} of them ALSO kept images — same conversation, same "
            "age, different outcome:"
        )
        for conv in sorted(mixed):
            print(f"      {conv[:70]}")
        print("  → whatever killed these is per-asset, not per-conversation.")


if __name__ == "__main__":
    main()