#!/usr/bin/env bash
# Monthly TVA basis aggregation for Arcodange — ready to transcribe onto
# CA3 (régime réel normal) or CA12 (réel simplifié) declarations.
#
# Usage:
#   tva-by-month.sh [--year YYYY] [--since YYYY-MM-DD] [--until YYYY-MM-DD]
#
# Groups every visible invoice line by (year-month, tva_tx). Sums HT and TVA.
# Surfaces credit notes correctly (negative HT cancels out at the basis level).
#
# Mapping to French TVA forms (régime réel normal CA3):
#   - tva_tx == 0 AND client country != FR
#     → ligne A4 "Autres opérations imposables" if reverse-charge intra-UE
#     → ligne E2 "Exportations hors UE" if extra-UE
#     (the line script tva-line-detail.sh distinguishes these)
#   - tva_tx == 20 → A1 base + 8 TVA collectée
#   - tva_tx == 10 → A1 (taux réduit) base + 9 TVA collectée
#   - tva_tx == 5.5 → A1 base + 9B TVA collectée
#   - tva_tx == 2.1 → A1 base + 9C TVA collectée
#
# Today Arcodange is monorange autoliquidation 259-1° on KM (extra-UE), so
# everything lands on E2. As soon as a French B2B client is invoiced, the
# 20 % bucket will populate.

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
DOL_CURL="${SCRIPT_DIR}/../../dolibarr/scripts/dol-curl.sh"

SINCE=""
UNTIL=""
YEAR=""
while [[ $# -gt 0 ]]; do
  case "$1" in
    --since) SINCE="$2"; shift 2 ;;
    --until) UNTIL="$2"; shift 2 ;;
    --year)  YEAR="$2"; SINCE="$2-01-01"; UNTIL="$2-12-31"; shift 2 ;;
    -h|--help) sed -n '2,30p' "$0" | sed 's/^# \{0,1\}//'; exit 0 ;;
    *) echo "tva-by-month.sh: unknown arg: $1" >&2; exit 2 ;;
  esac
done

WORK="$(mktemp -d -t tvamonth.XXXXXX)"
trap 'rm -rf "${WORK}"' EXIT

"${DOL_CURL}" '/invoices?limit=500&sortfield=t.datef&sortorder=ASC' > "${WORK}/inv.json"

# Per-invoice detail fetch (the list endpoint doesn't include line-level tva_tx)
IDS=$(python3 -c "import json,sys; print(' '.join(str(r['id']) for r in json.load(open(sys.argv[1]))))" "${WORK}/inv.json")
mkdir -p "${WORK}/detail"
for id in ${IDS}; do
  "${DOL_CURL}" "/invoices/${id}" > "${WORK}/detail/${id}.json"
done

python3 - "${WORK}" "${SINCE}" "${UNTIL}" "${YEAR}" <<'PY'
import json, sys, os, collections, datetime
work, since, until, year_arg = sys.argv[1:5]

def in_window(ts):
    if not ts: return False
    d = datetime.date.fromtimestamp(int(ts))
    if since and d < datetime.date.fromisoformat(since): return False
    if until and d > datetime.date.fromisoformat(until): return False
    return True

# key: (yyyy-mm, tva_tx) -> {ht, tva, count}
agg = collections.defaultdict(lambda: {"ht":0.0,"tva":0.0,"count":0})
for fn in sorted(os.listdir(os.path.join(work,"detail"))):
    try: inv = json.load(open(os.path.join(work,"detail",fn)))
    except json.JSONDecodeError: continue
    ts = int(inv.get("date") or 0)
    if not in_window(ts): continue
    ym = datetime.date.fromtimestamp(ts).strftime("%Y-%m")
    for line in inv.get("lines") or []:
        tx = float(line.get("tva_tx") or 0)
        # Normalize tva_tx — Dolibarr returns "0.0000" / "20.0000" strings as numbers
        tx = round(tx, 4)
        ht  = float(line.get("total_ht")  or 0)
        tva = float(line.get("total_tva") or 0)
        agg[(ym, tx)]["ht"]    += ht
        agg[(ym, tx)]["tva"]   += tva
        agg[(ym, tx)]["count"] += 1

scope = f"window={since or '-inf'} → {until or '+inf'}"
if year_arg: scope = f"year {year_arg}"

print(f"# TVA basis by month × rate — {scope}")
print()
print(f"{'month':<8}  {'tva_tx':>7}  {'count':>5}  {'basis HT':>12}  {'TVA':>10}  CA3 line")
print("-" * 70)
total_ht = total_tva = 0.0
for key in sorted(agg):
    ym, tx = key
    s = agg[key]
    line = "(see tva-line-detail for cnty)" if tx == 0 else ("A1+8" if tx==20 else f"A1+? @ {tx}%")
    print(f"{ym:<8}  {tx:>7.4f}  {s['count']:>5}  {s['ht']:>12.2f}  {s['tva']:>10.2f}  {line}")
    total_ht  += s["ht"]
    total_tva += s["tva"]
print("-" * 70)
print(f"{'TOTAL':>16}  {' ':>13}  {total_ht:>12.2f}  {total_tva:>10.2f}")
print()
print("# Notes:")
print("#   - Lines with tva_tx==0 require country lookup to choose CA3 E2 (export hors UE)")
print("#     vs A4 (autoliquidation intra-UE). Run tva-line-detail.sh for that breakdown.")
print("#   - Credit notes (AVOIRs) show as negative HT and are correctly netted at basis.")
PY