"""
Dashboard tab: at-a-glance counts of what's come in.

Kept intentionally simple for now (stat cards, no charts) per the
"just a dashboard for now" scope. The stats themselves come from
app.workers.get_dashboard_stats(), so adding a new stat later is a
matter of adding a key there and a card here - this widget doesn't
know anything about how orders are fetched or stored.
"""
from __future__ import annotations

from PyQt6.QtCore import Qt
from PyQt6.QtWidgets import (
    QWidget,
    QGridLayout,
    QVBoxLayout,
    QHBoxLayout,
    QLabel,
    QFrame,
    QSizePolicy,
)


class StatCard(QFrame):
    def __init__(self, title: str, parent=None):
        super().__init__(parent)
        self.setFrameShape(QFrame.Shape.StyledPanel)
        self.setSizePolicy(QSizePolicy.Policy.Expanding, QSizePolicy.Policy.Preferred)

        layout = QVBoxLayout(self)
        self.value_label = QLabel("0")
        value_font = self.value_label.font()
        value_font.setPointSize(28)
        value_font.setBold(True)
        self.value_label.setFont(value_font)
        self.value_label.setAlignment(Qt.AlignmentFlag.AlignCenter)

        title_label = QLabel(title)
        title_label.setAlignment(Qt.AlignmentFlag.AlignCenter)
        title_label.setWordWrap(True)

        layout.addWidget(self.value_label)
        layout.addWidget(title_label)

    def set_value(self, value) -> None:
        self.value_label.setText(str(value))


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

        outer = QVBoxLayout(self)

        heading = QLabel("Today's Orders at a Glance")
        heading_font = heading.font()
        heading_font.setPointSize(16)
        heading_font.setBold(True)
        heading.setFont(heading_font)
        outer.addWidget(heading)

        # Top row: overall + per-source totals
        top_row = QHBoxLayout()
        self.total_card = StatCard("Total Orders")
        self.jira_card = StatCard("From JIRA")
        self.shipstation_card = StatCard("From ShipStation")
        for card in (self.total_card, self.jira_card, self.shipstation_card):
            top_row.addWidget(card)
        outer.addLayout(top_row)

        # Second row: per-company totals (grid so adding a 3rd company later just works)
        outer.addWidget(self._section_label("By Company"))
        self.company_grid = QGridLayout()
        self.company_cards: dict[str, StatCard] = {}
        outer.addLayout(self.company_grid)

        # Third row: cross-source matching, since JIRA and ShipStation are pulled independently
        outer.addWidget(self._section_label("JIRA <-> ShipStation Matching (by ticket #)"))
        match_row = QHBoxLayout()
        self.matched_card = StatCard("Matched in Both")
        self.jira_only_card = StatCard("JIRA Only (not yet in ShipStation)")
        self.shipstation_only_card = StatCard("ShipStation Only (no matching ticket)")
        for card in (self.matched_card, self.jira_only_card, self.shipstation_only_card):
            match_row.addWidget(card)
        outer.addLayout(match_row)

        outer.addStretch()

    @staticmethod
    def _section_label(text: str) -> QLabel:
        label = QLabel(text)
        font = label.font()
        font.setBold(True)
        label.setFont(font)
        return label

    def update_stats(self, stats: dict) -> None:
        self.total_card.set_value(stats.get("total", 0))
        self.jira_card.set_value(stats.get("by_source", {}).get("jira", 0))
        self.shipstation_card.set_value(stats.get("by_source", {}).get("shipstation", 0))

        self.matched_card.set_value(stats.get("matched_count", 0))
        self.jira_only_card.set_value(stats.get("jira_only_count", 0))
        self.shipstation_only_card.set_value(stats.get("shipstation_only_count", 0))

        by_company = stats.get("by_company", {})
        # Rebuild company cards if the set of companies changed (e.g. a 3rd company added)
        if set(by_company.keys()) != set(self.company_cards.keys()):
            self._rebuild_company_cards(by_company.keys())
        for company, count in by_company.items():
            self.company_cards[company].set_value(count)

    def _rebuild_company_cards(self, companies) -> None:
        while self.company_grid.count():
            item = self.company_grid.takeAt(0)
            widget = item.widget()
            if widget:
                widget.deleteLater()
        self.company_cards.clear()

        for i, company in enumerate(sorted(companies)):
            card = StatCard(company)
            self.company_cards[company] = card
            self.company_grid.addWidget(card, i // 3, i % 3)