"""Small SQLite layer. Each operation owns its connection and transaction."""
import os
import sqlite3
from contextlib import contextmanager
from pathlib import Path
from models import canonical_name, name_key, ASSET_TYPES


def db_path():
    return Path(os.environ.get('FINANCE_DB_PATH', '/data/finance.db'))


@contextmanager
def connect(path=None):
    db = sqlite3.connect(path or db_path(), timeout=5)
    db.row_factory = sqlite3.Row
    db.execute('PRAGMA foreign_keys = ON')
    db.execute('PRAGMA busy_timeout = 5000')
    try:
        with db:
            yield db
    finally:
        db.close()


def validate_asset(name, asset_type='other', ticker=None):
    name = canonical_name(name)
    if asset_type not in ASSET_TYPES:
        raise ValueError('Ungültiger Positionstyp.')
    ticker = (ticker or '').strip()
    if len(ticker) > 30:
        raise ValueError('Ticker darf maximal 30 Zeichen enthalten.')
    return name, ticker or None


def ensure_asset(db, name, asset_type='other', ticker=None):
    name, ticker = validate_asset(name, asset_type, ticker)
    db.execute('INSERT INTO assets (name, normalized_name, ticker, asset_type) VALUES (?, ?, ?, ?) ON CONFLICT(normalized_name) DO NOTHING',
               (name, name_key(name), ticker or None, asset_type))
    return db.execute('SELECT id FROM assets WHERE normalized_name = ?', (name_key(name),)).fetchone()['id']


def initialize(path=None):
    target = Path(path or db_path())
    target.parent.mkdir(parents=True, exist_ok=True)
    with connect(target) as db:
        first_setup = db.execute("SELECT 1 FROM sqlite_master WHERE type='table' AND name='assets'").fetchone() is None
        db.execute('PRAGMA journal_mode = WAL')
        db.executescript('''
        CREATE TABLE IF NOT EXISTS assets (
            id INTEGER PRIMARY KEY, name TEXT NOT NULL,
            normalized_name TEXT NOT NULL UNIQUE, ticker TEXT,
            asset_type TEXT NOT NULL CHECK(asset_type IN ('stock','etf','bond','crypto','interest','other')),
            active INTEGER NOT NULL DEFAULT 1 CHECK(active IN (0,1)),
            created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ','now'))
        );
        CREATE TABLE IF NOT EXISTS income_entries (
            id INTEGER PRIMARY KEY, date TEXT NOT NULL,
            asset_id INTEGER NOT NULL REFERENCES assets(id) ON DELETE RESTRICT,
            category TEXT NOT NULL CHECK(category IN ('dividend','interest','distribution','other')),
            amount INTEGER NOT NULL CHECK(typeof(amount) = 'integer' AND abs(amount) <= 99999999999),
            note TEXT, expected INTEGER NOT NULL DEFAULT 0 CHECK(expected IN (0,1)),
            received INTEGER NOT NULL DEFAULT 1 CHECK(received IN (0,1)),
            created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ','now')),
            updated_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ','now'))
        );
        CREATE INDEX IF NOT EXISTS income_date ON income_entries(date DESC, id DESC);
        CREATE INDEX IF NOT EXISTS income_asset ON income_entries(asset_id);
        CREATE TABLE IF NOT EXISTS import_records (
            fingerprint TEXT PRIMARY KEY,
            entry_id INTEGER REFERENCES income_entries(id) ON DELETE SET NULL,
            created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
        );
        PRAGMA user_version = 1;
        ''')
        if first_setup:
            for name, kind in [('AGNC','stock'), ('Main Street Capital','stock'), ('Capital Southwest','stock'),
                               ('Ares Capital','stock'), ('Realty Income','stock'), ('Enbridge','stock'),
                               ('Bayer','stock'), ('STOXX Global Select Dividend 100','etf'), ('airBaltic','bond')]:
                ensure_asset(db, name, kind)