Balance summary

"use client"

import { formatCurrency } from "@/lib/format"
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card"
import { LineChart } from "@/components/ui/line-chart"
import { StatCard } from "@/components/ui/stat-card"
import { StatCardGroup } from "@/components/ui/stat-card-group"

import { type BalanceSummary, type FlowPoint } from "../data"

const compact = (cents: number) => formatCurrency(cents / 100, "USD", { maximumFractionDigits: 0 })

/**
 * What came in, what went out and what was sold, as three tiles over the
 * same three flows by month. An island only because the chart draws in the
 * browser; the numbers arrive computed from the server page.
 */
export function BalanceSummaryPanel({ summary, flow }: { summary: BalanceSummary; flow: FlowPoint[] }) {
  return (
    <Card
      data-widget="widget-finance-crypto-balance-summary"
      role="region"
      aria-label="Balance summary"
      className="h-full"
    >
      <CardHeader>
        <CardTitle>Balance summary</CardTitle>
        <CardDescription>The three flows over the last seven months.</CardDescription>
      </CardHeader>
      <CardContent className="flex flex-col gap-4">
        <StatCardGroup columns={3} divided>
          <StatCard size="sm" label="Received" value={compact(summary.receivedCents)} description="from other wallets" />
          <StatCard size="sm" label="Sent" value={compact(summary.sentCents)} description="to other wallets" />
          <StatCard size="sm" label="Withdrawn" value={compact(summary.withdrawnCents)} description="sold for cash" />
        </StatCardGroup>
        <LineChart
          data={flow}
          index="month"
          series={[
            { key: "received", label: "Received" },
            { key: "sent", label: "Sent" },
            { key: "withdrawn", label: "Withdrawn" },
          ]}
          valueFormatter={(value) => formatCurrency(value, "USD", { compact: true })}
          height={260}
        />
      </CardContent>
    </Card>
  )
}

/**
 * What this page reads. Every holding comes from `db.holdings` and every
 * movement from `db.trades`; the balance, the wallet groups, the three
 * totals and the seven-month flow are rules over those rows, so nothing here
 * is a literal. "Now" is `REFERENCE_DATE`.
 *
 * The client islands import only the types below. The words the page puts on
 * a trade's kind live beside them in `components/crypto-vocabulary.ts`, so
 * nothing that reaches `db` is ever pulled into the browser.
 */
import { getInitials } from "@/lib/format"
import { REFERENCE_DATE, db, type Holding, type Member, type Trade } from "@/lib/sample-data"

export type TradeKind = Trade["kind"]
export type Wallet = Holding["wallet"]

/** One holding as the holdings table prints it. */
export type HoldingRow = {
  id: string
  asset: string
  symbol: string
  /** The letter in the tinted circle, in place of the coin's mark. */
  initial: string
  amount: number
  priceCents: number
  change24h: number
  wallet: Wallet
  /** What the holding is worth now, in cents. */
  valueCents: number
}

/** One movement as the activity list prints it. Exported because the order returns one. */
export type TradeRow = {
  id: string
  asset: string
  symbol: string
  initial: string
  kind: TradeKind
  amount: number
  priceCents: number
  valueCents: number
  at: Date
  status: Trade["status"]
}

// Read per call, never held at module scope: a holding bought into since the
// server started names its trades on the next render.
const assetsBySymbol = () => new Map(db.holdings.all().map((row) => [row.symbol, row.asset]))

const initialOf = (asset: string) => asset.charAt(0).toUpperCase()

export function toHoldingRow(row: Holding): HoldingRow {
  return {
    id: row.id,
    asset: row.asset,
    symbol: row.symbol,
    initial: initialOf(row.asset),
    amount: row.amount,
    priceCents: row.priceCents,
    change24h: row.change24h,
    wallet: row.wallet,
    valueCents: Math.round(row.amount * row.priceCents),
  }
}

export function toTradeRow(row: Trade, assets = assetsBySymbol()): TradeRow {
  const asset = assets.get(row.symbol) ?? row.symbol
  return {
    id: row.id,
    asset,
    symbol: row.symbol,
    initial: initialOf(asset),
    kind: row.kind,
    amount: row.amount,
    priceCents: row.priceCents,
    valueCents: Math.round(row.amount * row.priceCents),
    at: row.at,
    status: row.status,
  }
}

export type Overview = {
  transactions: number
  wallets: number
  balanceCents: number
  /** What the last day's prices did to the balance, in cents: each holding's value times its own move. */
  move24hCents: number
  /** The same move as a share of the balance — the last day's change, weighted by value. */
  change24h: number
}

/** The headline card: how many movements, how many wallets, and what it all adds up to. */
export function overview(): Overview {
  const holdings = db.holdings.all()
  const balanceCents = holdings.reduce((sum, row) => sum + row.amount * row.priceCents, 0)
  const move24hCents = holdings.reduce((sum, row) => sum + row.amount * row.priceCents * row.change24h, 0)
  return {
    transactions: db.trades.all().length,
    wallets: new Set(holdings.map((row) => row.wallet)).size,
    balanceCents,
    move24hCents,
    change24h: balanceCents === 0 ? 0 : move24hCents / balanceCents,
  }
}

export type WalletGroup = { wallet: Wallet; rows: HoldingRow[]; totalCents: number }

const WALLET_ORDER: Wallet[] = ["Main", "Savings", "Trading"]

/** Every holding under its wallet, the largest holding first inside each. */
export function walletGroups(): WalletGroup[] {
  const rows = db.holdings.all().map(toHoldingRow)
  return WALLET_ORDER.filter((wallet) => rows.some((row) => row.wallet === wallet)).map((wallet) => {
    const inWallet = rows.filter((row) => row.wallet === wallet).sort((a, b) => b.valueCents - a.valueCents)
    return { wallet, rows: inWallet, totalCents: inWallet.reduce((sum, row) => sum + row.valueCents, 0) }
  })
}

export type WalletSummary = {
  wallet: Wallet
  /** How many assets the wallet holds. */
  assets: number
  totalCents: number
  /** The wallet's last-day move, weighted by value. */
  change24h: number
  /** The largest holding in the wallet, and its share of the wallet. */
  top: { asset: string; share: number }
}

/** Each wallet on one line: what it holds, what that is worth, and how the day treated it. */
export function walletSummaries(): WalletSummary[] {
  return walletGroups().map((group) => {
    const [top] = group.rows
    const weighted = group.rows.reduce((sum, row) => sum + row.valueCents * row.change24h, 0)
    return {
      wallet: group.wallet,
      assets: group.rows.length,
      totalCents: group.totalCents,
      change24h: group.totalCents === 0 ? 0 : weighted / group.totalCents,
      top: {
        asset: top?.asset ?? "",
        share: top && group.totalCents > 0 ? top.valueCents / group.totalCents : 0,
      },
    }
  })
}

/** Every holding in every wallet, the largest first — the table under the desk. */
export function holdings(): HoldingRow[] {
  return db.holdings
    .all()
    .map(toHoldingRow)
    .sort((a, b) => b.valueCents - a.valueCents)
}

export type Coin = { symbol: string; asset: string; priceCents: number }

/** The assets the trade form offers: one entry per symbol, at today's price. */
export function coins(): Coin[] {
  const seen = new Map<string, Coin>()
  for (const row of db.holdings.all()) {
    if (!seen.has(row.symbol)) seen.set(row.symbol, { symbol: row.symbol, asset: row.asset, priceCents: row.priceCents })
  }
  return [...seen.values()]
}

/** Every movement, newest first. */
export function recentTrades(): TradeRow[] {
  const assets = assetsBySymbol()
  return db.trades
    .all()
    .sort((a, b) => b.at.getTime() - a.at.getTime())
    .map((row) => toTradeRow(row, assets))
}

export type BalanceSummary = { receivedCents: number; sentCents: number; withdrawnCents: number }

const valueOf = (rows: Trade[], kind: TradeKind) =>
  rows.filter((row) => row.kind === kind).reduce((sum, row) => sum + row.amount * row.priceCents, 0)

/** What came in from other wallets, what went out to them, and what was sold for cash. */
export function balanceSummary(): BalanceSummary {
  const rows = db.trades.all()
  return {
    receivedCents: valueOf(rows, "receive"),
    sentCents: valueOf(rows, "send"),
    withdrawnCents: valueOf(rows, "sell"),
  }
}

const MONTH = new Intl.DateTimeFormat("en-US", { month: "short", timeZone: "UTC" })

/** The first of the month `back` months before the reference month. */
function monthStart(back: number): Date {
  return new Date(Date.UTC(REFERENCE_DATE.getUTCFullYear(), REFERENCE_DATE.getUTCMonth() - back, 1))
}

export type FlowPoint = { month: string; received: number; sent: number; withdrawn: number }

/** The three flows by month over the last seven months, in dollars, oldest first. */
export function flowByMonth(): FlowPoint[] {
  const rows = db.trades.all()
  return Array.from({ length: 7 }, (_, index) => 6 - index).map((back) => {
    const start = monthStart(back)
    const end = monthStart(back - 1)
    const inMonth = rows.filter((row) => row.at >= start && row.at < end)
    return {
      month: MONTH.format(start),
      received: Math.round(valueOf(inMonth, "receive") / 100),
      sent: Math.round(valueOf(inMonth, "send") / 100),
      withdrawn: Math.round(valueOf(inMonth, "sell") / 100),
    }
  })
}

/** The bell's contents: the newest notifications, unread first in the panel. */
export function shellNotifications() {
  return db.notifications
    .all()
    .sort((a, b) => b.at.getTime() - a.at.getTime())
    .slice(0, 6)
    .map(({ id, title, description, at, read, href }) => ({ id, title, description, at, read, href }))
}

function ownerRow(): Member {
  return db.members.all().find((member) => member.role === "owner") ?? db.members.all()[0]
}

/** The person looking at the page: whoever owns this workspace. */
export function currentUser() {
  const owner = ownerRow()
  return { name: owner.name, email: owner.email, initials: getInitials(owner.name), avatarUrl: owner.avatarUrl }
}