"""Shared data layer for the txt3 BBS (telnet front-end).

Talks to the exact same SQLite database as the WAP/XHTML site, so accounts,
mail, forums and scores are identical across all three front-ends.

Password hashes are PHP `password_hash()` bcrypt ($2y$) values. Rather than
depend on a bcrypt wheel, we verify/create them by calling the php binary,
passing values through the environment so nothing is ever interpolated into
a shell string.
"""
import os
import json
import sqlite3
import subprocess
import time

DB_PATH = os.environ.get(
    "BBS_DB", "/home/txt3/domains/wap.txt3.net/public_html/data/wap.sqlite"
)
PHP_BIN = os.environ.get("BBS_PHP", "/usr/bin/php")


def connect():
    con = sqlite3.connect(DB_PATH, timeout=10)
    con.row_factory = sqlite3.Row
    con.execute("PRAGMA journal_mode = WAL")
    con.execute("PRAGMA foreign_keys = ON")
    con.execute("PRAGMA busy_timeout = 5000")
    return con


def q(con, sql, args=()):
    return con.execute(sql, args).fetchall()


def q1(con, sql, args=()):
    r = con.execute(sql, args).fetchone()
    return r


def ex(con, sql, args=()):
    cur = con.execute(sql, args)
    con.commit()
    return cur.lastrowid


# ---------------------------------------------------------------- passwords
def _php(code, env):
    e = dict(os.environ)
    e.update(env)
    try:
        out = subprocess.run(
            [PHP_BIN, "-r", code],
            capture_output=True, text=True, timeout=10, env=e,
        )
        return out.stdout.strip()
    except Exception:
        return ""


def verify_password(plain, hashed):
    return _php(
        'echo password_verify(getenv("BP_P"), getenv("BP_H")) ? "1" : "0";',
        {"BP_P": plain, "BP_H": hashed},
    ) == "1"


def hash_password(plain):
    h = _php(
        'echo password_hash(getenv("BP_P"), PASSWORD_DEFAULT);',
        {"BP_P": plain},
    )
    return h or None


# ---------------------------------------------------------------- users
def user_by_name(con, name):
    return q1(con, "SELECT * FROM users WHERE username=? COLLATE NOCASE", (name,))


def user_by_id(con, uid):
    return q1(con, "SELECT * FROM users WHERE id=?", (uid,))


def login(con, name, password):
    u = user_by_name(con, name)
    if not u or u["is_banned"]:
        return None
    if not verify_password(password, u["pass_hash"]):
        return None
    ex(con, "UPDATE users SET last_seen=? WHERE id=?", (int(time.time()), u["id"]))
    return u


def create_user(con, name, password):
    h = hash_password(password)
    if not h:
        return None
    now = int(time.time())
    uid = ex(
        con,
        "INSERT INTO users (username,pass_hash,is_admin,created_at,last_seen)"
        " VALUES (?,?,0,?,?)",
        (name, h, now, now),
    )
    return uid


def touch(con, uid):
    ex(con, "UPDATE users SET last_seen=? WHERE id=?", (int(time.time()), uid))


def unread(con, uid):
    return q1(con, "SELECT COUNT(*) c FROM messages WHERE to_id=? AND is_read=0",
              (uid,))["c"]


def ago(ts):
    d = max(0, int(time.time()) - int(ts or 0))
    if d < 60:
        return "%ds" % d
    if d < 3600:
        return "%dm" % (d // 60)
    if d < 86400:
        return "%dh" % (d // 3600)
    return "%dd" % (d // 86400)