splitbuddy/main.py

from __future__ import annotations
import os, sqlite3, csv, io, datetime as dt
from typing import Optional
from flask import Flask, g, request, redirect, url_for, render_template, send_file

app = Flask(__name__)

# ----- Config -----
DB_PATH  = os.environ.get("SPLITBUDDY_DB", "splitbuddy.db")
CURRENCY = "₪"
PERSON_A = os.environ.get("SPLITBUDDY_ME", "Me")        # you
PERSON_B = os.environ.get("SPLITBUDDY_ROOMIE", "Idan")  # roommate
DEFAULT_A_SHARE_PCT = 66.6667  # <-- you pay 2/3 by default

# ----- DB helpers -----
def get_db() -> sqlite3.Connection:
    if "db" not in g:
        g.db = sqlite3.connect(DB_PATH)
        g.db.row_factory = sqlite3.Row
    return g.db

@app.teardown_appcontext
def close_db(_=None):
    db = g.pop("db", None)
    if db is not None:
        db.close()

def init_db():
    db = get_db()
    db.execute("""
        CREATE TABLE IF NOT EXISTS entries (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            created_at TEXT NOT NULL,
            kind TEXT NOT NULL DEFAULT 'bill',  -- 'bill' | 'transfer'
            total REAL NOT NULL DEFAULT 0,      -- amount
            payer TEXT NOT NULL DEFAULT 'A',    -- 'A' (you) or 'B' (Idan)
            a_share REAL NOT NULL DEFAULT 0.666667,  -- your share (0..1) for bills
            method TEXT NOT NULL DEFAULT 'cash',
            note   TEXT
        )
    """)
    # Migrations (no-op if columns already exist)
    for ddl in [
        "ALTER TABLE entries ADD COLUMN kind TEXT NOT NULL DEFAULT 'bill'",
        "ALTER TABLE entries ADD COLUMN total REAL",
        "ALTER TABLE entries ADD COLUMN payer TEXT",
        "ALTER TABLE entries ADD COLUMN a_share REAL",
    ]:
        try:
            db.execute(ddl)
        except sqlite3.OperationalError:
            pass
    db.execute("""
        UPDATE entries
        SET kind   = COALESCE(kind, 'bill'),
            total  = COALESCE(total, 0),
            payer  = COALESCE(payer, 'A'),
            a_share= COALESCE(a_share, 0.666667)
    """)
    db.commit()

# ----- Utility & models -----
def _now_local_iso_min() -> str:
    return dt.datetime.now().replace(second=0, microsecond=0).isoformat(timespec="minutes")

class ByMethod:
    def __init__(self, cash=0.0, transfer=0.0, other=0.0):
        self.cash = cash; self.transfer = transfer; self.other = other

class Summary:
    def __init__(self, total: float, count: int, latest: Optional[str], by_method: ByMethod):
        self.total = total; self.count = count; self.latest = latest; self.by_method = by_method

def _delta_for_entry(kind: str, total: float, payer: str, a_share: float) -> float:
    """
    Positive => YOU owe Idan. Negative => Idan owes YOU.
    - bill:     delta = (your_share * total) - (total if YOU paid else 0)
    - transfer: delta = -total if YOU sent; +total if Idan sent
    """
    if kind == "transfer":
        return -total if payer == "A" else total
    paid_by_a = total if payer == "A" else 0.0
    return a_share * total - paid_by_a

# ----- Routes -----
@app.before_request
def _ensure_db():
    init_db()

@app.get("/")
def index():
    db = get_db()
    rows = db.execute("""
        SELECT id, created_at, kind, total, payer, a_share, method, note
        FROM entries
        ORDER BY datetime(created_at) DESC, id DESC
    """).fetchall()

    entries = []
    for r in rows:
        e = dict(r)
        e["delta"] = _delta_for_entry(e["kind"], e["total"], e["payer"], e["a_share"])
        entries.append(e)

    total_balance = sum(e["delta"] for e in entries) if entries else 0.0
    latest = entries[0]["created_at"] if entries else None
    bm = ByMethod(
        cash=sum(e["delta"] for e in entries if e["method"] == "cash"),
        transfer=sum(e["delta"] for e in entries if e["method"] == "transfer"),
        other=sum(e["delta"] for e in entries if e["method"] == "other"),
    )
    summary = Summary(total=total_balance, count=len(entries), latest=latest, by_method=bm)

    return render_template(
        "index.html",
        entries=entries,
        summary=summary,
        A=PERSON_A, B=PERSON_B,
        currency=CURRENCY,
        now_local=_now_local_iso_min(),
        default_a_share_pct=DEFAULT_A_SHARE_PCT,
    )

@app.post("/add")
def add():
    kind = (request.form.get("kind") or "bill").strip().lower()
    payer = (request.form.get("payer") or "A").strip().upper()
    total = request.form.get("total", type=float)
    a_share_pct = request.form.get("a_share_pct", type=float)
    method = (request.form.get("method") or "cash").strip().lower()
    note = (request.form.get("note") or "").strip()
    created_at = request.form.get("created_at") or _now_local_iso_min()

    if total is None or total < 0: return redirect(url_for("index"))
    if payer not in ("A","B"): payer = "A"
    if kind not in ("bill","transfer"): kind = "bill"

    if kind == "bill":
        if a_share_pct is None:
            a_share_pct = DEFAULT_A_SHARE_PCT
        a_share = max(0.0, min(100.0, a_share_pct)) / 100.0
    else:
        a_share = DEFAULT_A_SHARE_PCT / 100.0  # stored but ignored for transfers

    db = get_db()
    db.execute(
        "INSERT INTO entries (created_at, kind, total, payer, a_share, method, note) VALUES (?, ?, ?, ?, ?, ?, ?)",
        (created_at, kind, total, payer, a_share, method, note),
    )
    db.commit()
    return redirect(url_for("index"))

@app.post("/delete/<int:entry_id>")
def delete(entry_id: int):
    db = get_db()
    db.execute("DELETE FROM entries WHERE id = ?", (entry_id,))
    db.commit()
    return redirect(url_for("index"))

@app.get("/export.csv")
def export_csv():
    db = get_db()
    rows = db.execute("""
        SELECT id, created_at, kind, total, payer, a_share, method, note
        FROM entries
        ORDER BY datetime(created_at) DESC, id DESC
    """).fetchall()
    buff = io.StringIO()
    w = csv.writer(buff)
    w.writerow(["id","created_at","kind","payer","a_share_pct","total","method","note","delta"])
    for r in rows:
        a_share_pct = float(r["a_share"]) * 100.0
        delta = _delta_for_entry(r["kind"], r["total"], r["payer"], r["a_share"])
        w.writerow([r["id"], r["created_at"], r["kind"], r["payer"], f"{a_share_pct:.2f}",
                    f"{r['total']:.2f}", r["method"], r["note"] or "", f"{delta:.2f}"])
    buff.seek(0)
    return send_file(io.BytesIO(buff.read().encode("utf-8")), mimetype="text/csv",
                     as_attachment=True, download_name="splitbuddy_export.csv")

if __name__ == "__main__":
    os.makedirs(os.path.dirname(DB_PATH) or ".", exist_ok=True)
    with app.app_context():
        init_db()
    app.run(debug=True)