"""Сводка: успеваю ли я рассчитаться с пекарней."""

from __future__ import annotations

from PySide6.QtWidgets import (
    QGridLayout,
    QProgressBar,
    QScrollArea,
    QVBoxLayout,
    QWidget,
)

from .. import ledger
from .. import money as m
from . import theme
from . import widgets as w


class DashboardPage(QWidget):
    def __init__(self, ctx, parent=None):
        super().__init__(parent)
        self.ctx = ctx

        outer = QVBoxLayout(self)
        outer.setContentsMargins(0, 0, 0, 0)

        scroll = QScrollArea()
        scroll.setWidgetResizable(True)
        scroll.setFrameShape(QScrollArea.NoFrame)
        outer.addWidget(scroll)

        self.body = QWidget()
        self.layout = QVBoxLayout(self.body)
        self.layout.setContentsMargins(20, 18, 20, 18)
        self.layout.setSpacing(14)
        scroll.setWidget(self.body)

    def refresh(self) -> None:
        # Сводка целиком собирается заново: цифр немного, а следить за тем,
        # какая карточка устарела, вышло бы дороже, чем перерисовать всё.
        while self.layout.count():
            item = self.layout.takeAt(0)
            widget = item.widget()
            if widget is not None:
                # setParent(None) обязателен: deleteLater откладывает удаление
                # до следующего прохода цикла событий, и до тех пор старые
                # карточки остаются детьми body.
                widget.setParent(None)
                widget.deleteLater()

        report = self.ctx.report
        summary = report.summary
        currency = self.ctx.currency

        self.layout.addWidget(w.heading("Сводка"))

        if report.warnings:
            self.layout.addWidget(w.warning_banner(report.warnings))

        self.layout.addWidget(self._metrics(summary, currency))

        if summary.next_due is not None:
            self.layout.addWidget(self._deadline_card(summary.next_due, currency))

        self.layout.addWidget(w.label("Открытые партии", "h2"))
        self.layout.addWidget(self._open_batches(report, currency))

        self.layout.addWidget(w.label("Остатки", "h2"))
        self.layout.addWidget(self._stock(report, currency))
        self.layout.addStretch(1)

    def _metrics(self, summary, currency: str) -> QWidget:
        holder = QWidget()
        grid = QGridLayout(holder)
        grid.setContentsMargins(0, 0, 0, 0)
        grid.setSpacing(10)

        overdue_hint = (
            f"просрочено партий: {summary.overdue_count}" if summary.overdue_count else "всё в срок"
        )
        cards = [
            (
                "Долг пекарне",
                m.fmt_money(summary.owed_to_bakery, currency),
                overdue_hint,
                theme.DANGER if summary.overdue_count else theme.TEXT,
            ),
            (
                "Мне должны",
                m.fmt_money(summary.receivable, currency),
                "по неоплаченным продажам",
                theme.WARN if summary.receivable > 0 else theme.TEXT,
            ),
            (
                "Прибыль",
                m.fmt_money(summary.profit, currency),
                f"наценка {m.fmt_money(summary.gross_margin, currency)} "
                f"− съедено {m.fmt_money(summary.consumed_cost, currency)}",
                theme.OK if summary.profit > 0 else theme.DANGER if summary.profit < 0 else theme.TEXT,
            ),
            (
                "Остаток на складе",
                m.fmt_qty(summary.stock_qty),
                f"по себестоимости {m.fmt_money(summary.stock_cost, currency)}",
                theme.TEXT,
            ),
        ]
        for index, (title, value, hint, color) in enumerate(cards):
            grid.addWidget(w.metric_card(title, value, hint, color), 0, index)
            grid.setColumnStretch(index, 1)
        return holder

    def _deadline_card(self, report, currency: str) -> QWidget:
        card = w.card()
        layout = QVBoxLayout(card)
        layout.setContentsMargins(16, 14, 16, 14)
        layout.setSpacing(8)

        color = theme.STATUS_COLORS.get(report.status, theme.ACCENT)
        when = (
            f"осталось {report.days_left} дн."
            if report.days_left >= 0
            else f"просрочена на {-report.days_left} дн."
        )
        layout.addWidget(
            w.label(
                f"Ближайший срок — партия {report.label}, до "
                f"{report.batch.due_date.strftime('%d.%m.%Y')} ({when})",
                "h2",
                color,
            )
        )

        bar = QProgressBar()
        bar.setRange(0, 100)
        bar.setValue(int(min(100, max(0, report.coverage_pct))))
        bar.setFormat(f"собрано {report.coverage_pct}% себестоимости")
        bar.setStyleSheet(f"QProgressBar::chunk {{ background: {color}; }}")
        layout.addWidget(bar)

        layout.addWidget(
            w.label(
                f"Надо вернуть {m.fmt_money(report.remaining_to_bakery, currency)} • "
                f"собрано деньгами {m.fmt_money(report.cash_collected, currency)} • "
                f"осталось собрать {m.fmt_money(report.still_to_collect, currency)}",
                "dim",
            )
        )
        return card

    def _open_batches(self, report, currency: str) -> QWidget:
        table = w.table(
            ["№", "Дата", "Покрыть до", "Осталось", "Долг", "Собрано", "Покрытие", "Статус"],
            stretch_column=7,
        )
        table.setMaximumHeight(220)

        rows = []
        for item in sorted(report.open_batches, key=lambda r: r.batch.due_date):
            color = theme.STATUS_COLORS.get(item.status, "")
            days = (
                f"{item.days_left} дн."
                if item.days_left >= 0
                else f"просрочено на {-item.days_left} дн."
            )
            rows.append(
                [
                    w.sortable_num_item(str(item.batch.number), item.batch.number),
                    w.text_item(item.batch.date.strftime("%d.%m.%Y")),
                    w.text_item(item.batch.due_date.strftime("%d.%m.%Y")),
                    w.text_item(days, color),
                    w.sortable_num_item(
                        m.fmt_money(item.remaining_to_bakery, currency), item.remaining_to_bakery
                    ),
                    w.sortable_num_item(m.fmt_money(item.cash_collected, currency), item.cash_collected),
                    w.sortable_num_item(f"{item.coverage_pct}%", item.coverage_pct, color),
                    w.text_item(ledger.STATUS_LABELS.get(item.status, ""), color),
                ]
            )
        w.fill(table, rows)

        if not rows:
            return w.label("Открытых партий нет — пекарня может печь дальше.", "dim")
        return table

    def _stock(self, report, currency: str) -> QWidget:
        rows = [row for row in report.stock if row.qty > 0]
        if not rows:
            return w.label("Булок не осталось.", "dim")

        table = w.table(["Товар", "Остаток", "Ед.", "По себестоимости"])
        table.setMaximumHeight(220)
        w.fill(
            table,
            [
                [
                    w.text_item(row.name),
                    w.sortable_num_item(m.fmt_qty(row.qty), row.qty),
                    w.text_item(row.unit),
                    w.sortable_num_item(m.fmt_money(row.cost, currency), row.cost),
                ]
                for row in rows
            ],
        )
        return table