"""Dashboard web pemilih BP databisnisid — baca `voters.db`, sajikan spec-list.

Read-only (V10/V11): tidak pernah menulis ke DB. Data pemilih disegarkan oleh
`get_voters.py` (run harian / cron). Saldo liquid akun diambil langsung dari
API databisnis dengan cache TTL singkat (V16). Styling per `DESIGN.md`.
Konfigurasi dari env/`.env`.
"""

import time
from datetime import datetime

import requests
from flask import Flask, abort, jsonify, render_template, request

import db
from config import (DASH_HOST, DASH_LIQUID_TTL, DASH_PORT, DATABISNIS_API,
                    PAGE_SIZE, TARGET_BP)

SEARCH_CAP = 500
MAX_Q_LEN = 64

# Tabel distribute_payments diperlukan utk kolom TOTAL REWARD (V29). Dipastikan
# ada sekali per worker (idempoten) sebelum query list/search dijalankan.
_dist_schema_ready = False


def _ensure_dist_schema():
    global _dist_schema_ready
    if not _dist_schema_ready:
        db.ensure_distribute_schema()
        _dist_schema_ready = True


app = Flask(__name__)


@app.after_request
def _no_cache_html(resp):
    """HTML ⊥ di-cache browser (V28): tautan style.css memakai ?v= utk
    memaksa fetch versi baru; halaman itu sendiri tak boleh heuristik cache
    sehingga tiap muat selalu menarik tautan ber-version tsb."""
    if resp.mimetype == 'text/html':
        resp.headers['Cache-Control'] = 'no-store'
    return resp

# Cache saldo liquid per worker (in-memory, ⊥ tulis DB). `at` mencatat
# kapan sukses ATAU gagal terakhir → API dihubungi paling banyak sekali
# per TTL (cooldown saat gagal pun ikut mencegah pukulan berulang).
_liquid_cache = {'at': 0.0, 'value': None}


@app.template_filter('vex')
def vex(value):
    """Format jumlah VEX ala id-ID (koma ribuan, titik desimal)."""
    return f'{value:,.4f}'.replace(',', '\u00a0').replace('.', ',').replace('\u00a0', '.')


@app.template_filter('shortdate')
def shortdate(value):
    """Potong stempel waktu ISO → YYYY-MM-DD (untuk kolom vote terakhir)."""
    if not value:
        return '—'
    try:
        return datetime.fromisoformat(value).strftime('%Y-%m-%d')
    except ValueError:
        return '—'


def _get_liquid_vex():
    """V16: saldo liquid VEX akun TARGET_BP, cache TTL + cooldown kegagalan.

    Ambil `account.core_liquid_balance` dari API databisnis. Bila TTL belum
    lewat → nilai cache. Bila API gagal → nilai lama tetap dipakai (atau None
    bila belum pernah sukses), dan `at` ikut diset → API tak dipukul berulang.
    """
    now = time.monotonic()
    if _liquid_cache['value'] is not None and now - _liquid_cache['at'] < DASH_LIQUID_TTL:
        return _liquid_cache['value']
    value = None
    try:
        resp = requests.get(
            f'{DATABISNIS_API}/v2/state/get_account',
            params={'account': TARGET_BP},
            timeout=8,
        )
        resp.raise_for_status()
        raw = resp.json().get('account', {}).get('core_liquid_balance')
        if raw:
            value = float(raw.split()[0])
    except (requests.RequestException, KeyError, TypeError, ValueError):
        value = _liquid_cache['value']  # gagal → nilai lama bila ada
    _liquid_cache.update(at=now, value=value)
    return value


def _escape_like(q):
    """Escape wildcard LIKE agar `%`/`_`/`!` dari pengguna tidak jadi pola.

    `!` dipakai sebagai karakter escape, bukan backslash: backslash bermasalah
    di literal string MySQL (`'\'` memutus string), sedangkan `!` netral di
    kedua backend (sqlite & mysql sama-sama paham `ESCAPE '!'`).
    """
    return (q.replace('!', '!!')
             .replace('%', '!%')
             .replace('_', '!_'))


def _filter_sql(q, tbl=''):
    """V11: klausa WHERE + params untuk filter owner substring.

    `tbl` = prefix kolom owner (mis. `v.`) bila query memakai JOIN; kosong utk
    query tunggal agar kolom tak ambigu dengan kolom `owner` dari subquery.
    """
    clauses = []
    params = []
    if q:
        clauses.append(f"{tbl}owner LIKE %s ESCAPE '!'")
        params.append(f'%{_escape_like(q)}%')
    if not clauses:
        return '', []
    return 'WHERE ' + ' AND '.join(clauses), params


def _reward_join():
    """V29: total reward per voter = Σ amount distribute_payments status=sent.

    Gabung (LEFT) subquery agregat agar baris tanpa transfer tetap tampil dgn
    reward 0. Hanya status `sent` (⊥ failed/pending) → tidak ada dobel hitung
    saat baris gagal ikut run berikutnya.
    """
    return ('LEFT JOIN (SELECT owner, SUM(amount) AS total '
            '             FROM distribute_payments '
            '             WHERE status = %s GROUP BY owner) rw '
            '  ON rw.owner = v.owner'), ['sent']


def _db_rows(page, q):
    """V10/V11: satu halaman, urut staked DESC lalu owner ASC; rank global.

    Rank via correlated-count (bukan ROW_NUMBER): SQLite mendorong WHERE masuk ke
    subquery sebelum window function, sehingga ROW_NUMBER jadi rank-dalam-filter.
    Correlated count selalu menghitung atas SELURUH tabel → rank tetap global.
    """
    offset = (page - 1) * PAGE_SIZE
    where, params = _filter_sql(q, 'v.')
    rw_join, rw_params = _reward_join()
    sql = (
        'SELECT v.owner, v.staked, v.weight, v.scanned_at, '
        '  (SELECT COUNT(*) FROM voters v2 '
        '   WHERE v2.staked > v.staked '
        '      OR (v2.staked = v.staked AND v2.owner <= v.owner)) AS rn, '
        '  v.last_vote, '
        '  COALESCE(rw.total, 0) '
        'FROM voters v ' + rw_join + ' ' + where + ' '
        'ORDER BY v.staked DESC, v.owner ASC LIMIT %s OFFSET %s'
    )
    return db.query(sql, rw_params + params + [PAGE_SIZE, offset])


def _count(q):
    """V11: banyak baris cocok filter (atau total bila tanpa filter)."""
    where, params = _filter_sql(q)
    return db.queryone(
        'SELECT COUNT(*) FROM voters ' + where, params
    )[0]


def _stats():
    """Ringkasan agregat untuk band spec (selalu global, ⊥ dipengaruhi search)."""
    row = db.queryone(
        'SELECT COUNT(*), COALESCE(SUM(staked), 0), COALESCE(MAX(staked), 0) '
        'FROM voters'
    )
    total_voters, total_staked, top_staked = row
    scanned = db.queryone(
        'SELECT COALESCE(MAX(scanned_at), \'\') FROM voters'
    )[0]
    return total_voters, total_staked, top_staked, scanned


@app.get('/')
def index():
    try:
        page = max(1, int(request.args.get('page', 1)))
    except ValueError:
        abort(400)
    q = request.args.get('q', '').strip()[:MAX_Q_LEN]
    _ensure_dist_schema()
    total_voters, total_staked, top_staked, scanned = _stats()
    liquid_vex = _get_liquid_vex()
    filtered_count = _count(q)
    total_pages = max(1, (filtered_count + PAGE_SIZE - 1) // PAGE_SIZE)
    page = min(page, total_pages)
    rows = _db_rows(page, q)

    return render_template(
        'index.html',
        bp=TARGET_BP,
        rows=rows,
        page=page,
        total_pages=total_pages,
        total_voters=total_voters,
        total_staked=total_staked,
        top_staked=top_staked,
        liquid_vex=liquid_vex,
        scanned=scanned,
        q=q,
        filtered_count=filtered_count,
    )


@app.get('/api/search')
def api_search():
    """V11: JSON hasil pencarian owner (substring), urut staked DESC, rank global.

    Menyertakan `total_reward` (V29) agar hasil search sama kolomnya dgn list.
    """
    q = request.args.get('q', '').strip()[:MAX_Q_LEN]
    _ensure_dist_schema()
    where, params = _filter_sql(q, 'v.')
    rw_join, rw_params = _reward_join()
    sql = (
        'SELECT v.owner, v.staked, v.weight, '
        '  (SELECT COUNT(*) FROM voters v2 '
        '   WHERE v2.staked > v.staked '
        '      OR (v2.staked = v.staked AND v2.owner <= v.owner)) AS rn, '
        '  v.last_vote, '
        '  COALESCE(rw.total, 0) '
        'FROM voters v ' + rw_join + ' ' + where + ' '
        'ORDER BY v.staked DESC, v.owner ASC LIMIT %s'
    )
    rows = db.query(sql, rw_params + params + [SEARCH_CAP])
    return jsonify({
        'query': q,
        'count': len(rows),
        'cap': SEARCH_CAP,
        'results': [
            {
                'owner': r[0], 'staked': r[1], 'weight': r[2],
                'rank': r[3], 'last_vote': r[4], 'total_reward': r[5],
            }
            for r in rows
        ],
    })


@app.get('/history')
def history():
    """V27: riwayat distribusi profit-share (read-only) — runs + per-pemilih.

    Payments hanya run terbaru (V28); tanggal run terbaru ditampilkan di judul.
    """
    runs = db.list_runs()
    latest = runs[0][0] if runs else None
    payments = db.list_payments(run_id=latest)
    return render_template('history.html', runs=runs, payments=payments,
                           latest_date=runs[0][1] if runs else None,
                           bp=TARGET_BP)


if __name__ == '__main__':
    app.run(host=DASH_HOST, port=DASH_PORT, debug=False)