"""Merge every stock folder into one catalog the server can match against.

The demo had five stock folders and the server could only read one, so a shelf
holding anything outside the active folder came back blank. SKU ids are unique
across the folders (`sku_0xx`, `sku_lxx`, `sku_mxx`, `sku_kxx`), so the union is
a plain copy plus a CSV concat - no id rewriting, no dedup heuristics.

`stock-demo` is byte-identical to `stock-mediya` + `stock-milk150`, so it is not
a source: including it would only duplicate 62 images.

Run: .venv/bin/python code/build_stock_all.py
"""

from __future__ import annotations

import csv
import os
import shutil
import sys

HERE = os.path.dirname(os.path.abspath(__file__))
ROOT = os.path.dirname(HERE)
SOURCES = ("stock", "stock-lopia", "stock-mediya", "stock-milk150")
DEST = os.path.join(ROOT, "stock-all")
IMAGE_SUFFIXES = (".jpg", ".jpeg", ".png")
FIELDS = ("SKU_ID", "product_name", "receipt_date", "expiration_date",
          "number_in", "number_out", "number_on", "image_link", "price")


def main() -> int:
    if os.path.isdir(DEST):
        shutil.rmtree(DEST)
    os.makedirs(DEST)

    rows: list[dict] = []
    seen_sku: dict[str, str] = {}
    copied = 0
    for source in SOURCES:
        directory = os.path.join(ROOT, source)
        if not os.path.isdir(directory):
            print(f"skip {source}: not a directory", file=sys.stderr)
            continue
        for name in sorted(os.listdir(directory)):
            if not name.lower().endswith(IMAGE_SUFFIXES):
                continue
            target = os.path.join(DEST, name)
            if os.path.exists(target):
                # Same filename in two folders is the same product photographed
                # once; the first copy wins and the duplicate is reported.
                print(f"duplicate image {name} from {source}", file=sys.stderr)
                continue
            shutil.copy2(os.path.join(directory, name), target)
            copied += 1
        csv_path = os.path.join(directory, "stock.csv")
        if not os.path.exists(csv_path):
            continue
        with open(csv_path, newline="", encoding="utf-8") as handle:
            for row in csv.DictReader(handle):
                sku = (row.get("SKU_ID") or "").strip()
                if not sku:
                    continue
                if sku in seen_sku:
                    print(f"duplicate SKU {sku} in {source} (kept {seen_sku[sku]})",
                          file=sys.stderr)
                    continue
                seen_sku[sku] = source
                rows.append({field: (row.get(field) or "").strip() for field in FIELDS})

    with open(os.path.join(DEST, "stock.csv"), "w", newline="", encoding="utf-8") as handle:
        writer = csv.DictWriter(handle, fieldnames=FIELDS)
        writer.writeheader()
        writer.writerows(rows)

    print(f"{DEST}: {copied} images, {len(rows)} SKUs")
    return 0


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