"""Dialogue Fusion de PDF avec reordonnement drag & drop."""

from PyQt6.QtWidgets import (QDialog, QVBoxLayout, QHBoxLayout, QLabel,
                              QListWidget, QListWidgetItem, QAbstractItemView,
                              QPushButton, QDialogButtonBox, QFileDialog)
from PyQt6.QtCore import Qt, QSize


class MergeDialog(QDialog):
    def __init__(self, initial_files=None, parent=None):
        super().__init__(parent)
        self.setWindowTitle("Fusionner des PDF")
        self.setMinimumSize(500, 400)
        self._files = list(initial_files or [])
        self._setup_ui()
        self._refresh_list()

    def _setup_ui(self):
        layout = QVBoxLayout(self)

        layout.addWidget(QLabel("Glissez les fichiers pour reordonner. Cliquez Ajouter pour en ajouter."))

        self._list = QListWidget()
        self._list.setDragDropMode(QAbstractItemView.DragDropMode.InternalMove)
        self._list.setDefaultDropAction(Qt.DropAction.MoveAction)
        self._list.setStyleSheet("""
            QListWidget { background: #fff; border: 1px solid #d0d0d0; border-radius: 6px; padding: 4px; }
            QListWidget::item { padding: 8px; border-bottom: 1px solid #eee; }
            QListWidget::item:selected { background: #e0f4ff; color: #006fa6; }
        """)
        layout.addWidget(self._list)

        btn_layout = QHBoxLayout()
        btn_add = QPushButton("Ajouter des PDF...")
        btn_add.clicked.connect(self._add_files)
        btn_layout.addWidget(btn_add)

        btn_remove = QPushButton("Retirer")
        btn_remove.clicked.connect(self._remove_file)
        btn_layout.addWidget(btn_remove)

        btn_up = QPushButton("Monter")
        btn_up.clicked.connect(self._move_up)
        btn_layout.addWidget(btn_up)

        btn_down = QPushButton("Descendre")
        btn_down.clicked.connect(self._move_down)
        btn_layout.addWidget(btn_down)

        layout.addLayout(btn_layout)

        self._count_label = QLabel("")
        layout.addWidget(self._count_label)

        buttons = QDialogButtonBox(
            QDialogButtonBox.StandardButton.Ok | QDialogButtonBox.StandardButton.Cancel
        )
        buttons.accepted.connect(self.accept)
        buttons.rejected.connect(self.reject)
        layout.addWidget(buttons)

    def _refresh_list(self):
        self._list.clear()
        for i, path in enumerate(self._files):
            import os
            name = os.path.basename(path)
            item = QListWidgetItem(f"{i+1}. {name}")
            item.setData(Qt.ItemDataRole.UserRole, path)
            item.setToolTip(path)
            self._list.addItem(item)
        self._count_label.setText(f"{len(self._files)} fichier(s)")

    def _add_files(self):
        paths, _ = QFileDialog.getOpenFileNames(self, "Ajouter des PDF", "", "PDF (*.pdf)")
        if paths:
            self._files.extend(paths)
            self._refresh_list()

    def _remove_file(self):
        row = self._list.currentRow()
        if row >= 0:
            self._files.pop(row)
            self._refresh_list()

    def _move_up(self):
        row = self._list.currentRow()
        if row > 0:
            self._files[row], self._files[row-1] = self._files[row-1], self._files[row]
            self._refresh_list()
            self._list.setCurrentRow(row - 1)

    def _move_down(self):
        row = self._list.currentRow()
        if 0 <= row < len(self._files) - 1:
            self._files[row], self._files[row+1] = self._files[row+1], self._files[row]
            self._refresh_list()
            self._list.setCurrentRow(row + 1)

    def get_files(self):
        # Relire l'ordre depuis la liste (drag & drop peut avoir change)
        files = []
        for i in range(self._list.count()):
            item = self._list.item(i)
            files.append(item.data(Qt.ItemDataRole.UserRole))
        return files