from __future__ import annotations
from PyQt6.QtWidgets import (
    QWidget, QVBoxLayout, QTabWidget,
    QListWidget, QListWidgetItem, QLabel,
    QStyledItemDelegate, QApplication,
)
from PyQt6.QtCore import Qt, pyqtSignal, QSize, QRect
from PyQt6.QtGui import QColor, QPainter, QFontMetrics
from core.models import Article

_LINE2_ROLE = Qt.ItemDataRole.UserRole + 1


class ArticleItemDelegate(QStyledItemDelegate):
    def paint(self, painter: QPainter, option, index):
        painter.save()
        self.initStyleOption(option, index)
        style = option.widget.style() if option.widget else QApplication.style()
        style.drawPrimitive(style.PrimitiveElement.PE_PanelItemViewItem, option, painter, option.widget)

        rect: QRect = option.rect
        fm = QFontMetrics(option.font)
        line_h = fm.height()
        pad = 4

        line1 = index.data(Qt.ItemDataRole.DisplayRole) or ""
        line2 = index.data(_LINE2_ROLE) or ""
        fg = index.data(Qt.ItemDataRole.ForegroundRole)

        painter.setPen(fg.color() if fg else option.palette.text().color())
        r1 = QRect(rect.left() + pad, rect.top() + pad, rect.width() - pad * 2, line_h)
        painter.drawText(r1, Qt.TextFlag.TextSingleLine, line1)

        if line2:
            painter.setPen(QColor("#888"))
            r2 = QRect(rect.left() + pad, rect.top() + pad + line_h + 2, rect.width() - pad * 2, line_h)
            painter.drawText(r2, Qt.TextFlag.TextSingleLine, line2)

        painter.restore()

    def sizeHint(self, option, index):
        fm = QFontMetrics(option.font)
        line_h = fm.height()
        pad = 4
        line2 = index.data(_LINE2_ROLE) or ""
        height = (line_h * 2 + 2 + pad * 2) if line2 else (line_h + pad * 2)
        return QSize(0, height)


class ArticleItem(QListWidgetItem):
    def __init__(self, article: Article):
        super().__init__()
        self.article = article
        if article.has_translation:
            badge = "🇬🇧 ✓" if article.lang == "it" else "🇮🇹 ✓"
        else:
            badge = "🇬🇧 ✗" if article.lang == "it" else "🇮🇹 ✗"
        line1 = f"{article.slug}  [{badge}]"
        if article.draft:
            line1 = f"[DRAFT]  {line1}"

        parts = []
        if article.meta_type:
            parts.append(article.meta_type)
        if article.meta_date:
            parts.append(article.meta_date)
        if article.meta_tags:
            parts.append(f"#{article.meta_tags.replace(', ', '  #')}")
        if article.meta_categories:
            parts.append(f"[{article.meta_categories}]")
        line2 = "  ".join(parts) if parts else ""

        self.setText(line1)
        self.setData(_LINE2_ROLE, line2)

        if article.draft:
            self.setForeground(QColor("#f59e0b"))
        elif not article.has_translation:
            self.setForeground(QColor("#ff6b6b"))


class ArticlesView(QWidget):
    article_selected = pyqtSignal(object)  # Article
    translate_requested = pyqtSignal(object)  # Article

    def __init__(self, parent=None):
        super().__init__(parent)
        self._articles: list[Article] = []
        self._build_ui()

    def _build_ui(self):
        layout = QVBoxLayout(self)
        layout.setContentsMargins(0, 0, 0, 0)
        self._tabs = QTabWidget()
        self._tabs.setStyleSheet("QTabBar::tab { padding: 6px 16px; }")
        self._list_it = QListWidget()
        self._list_it.setItemDelegate(ArticleItemDelegate(self._list_it))
        self._list_en = QListWidget()
        self._list_en.setItemDelegate(ArticleItemDelegate(self._list_en))
        self._tabs.addTab(self._list_it, "🇮🇹 Italiano")
        self._tabs.addTab(self._list_en, "🇬🇧 English")
        layout.addWidget(self._tabs)
        self._list_it.itemClicked.connect(lambda item: self.article_selected.emit(item.article))
        self._list_en.itemClicked.connect(lambda item: self.article_selected.emit(item.article))

    def set_articles(self, articles: list[Article]):
        self._articles = articles
        self._list_it.clear()
        self._list_en.clear()
        for a in articles:
            item = ArticleItem(a)
            if a.lang == "it":
                self._list_it.addItem(item)
            else:
                self._list_en.addItem(item)


class MissingTranslationView(QWidget):
    article_selected = pyqtSignal(object)  # Article
    translate_requested = pyqtSignal(object)  # Article

    def __init__(self, parent=None):
        super().__init__(parent)
        self._build_ui()

    def _build_ui(self):
        layout = QVBoxLayout(self)
        header = QLabel("⚠️ Articoli senza traduzione")
        header.setStyleSheet("color: #ff6b6b; font-weight: bold; font-size: 13px; padding: 10px;")
        layout.addWidget(header)
        self._list = QListWidget()
        self._list.setItemDelegate(ArticleItemDelegate(self._list))
        layout.addWidget(self._list)
        self._list.itemClicked.connect(lambda item: self.article_selected.emit(item.article))

    def set_articles(self, articles: list[Article]):
        self._list.clear()
        missing = [a for a in articles if not a.has_translation]
        for a in missing:
            lang_other = "🇬🇧" if a.lang == "it" else "🇮🇹"
            item = ArticleItem(a)
            item.setText(f"{a.slug}  [manca {lang_other}]  ({a.lang.upper()})")
            item.setData(_LINE2_ROLE, "")
            self._list.addItem(item)