"""Paso 2: selección de plantilla de biblioteca curada."""

from __future__ import annotations

from PySide6.QtCore import Qt
from PySide6.QtWidgets import (
    QHBoxLayout,
    QLabel,
    QLineEdit,
    QListWidget,
    QListWidgetItem,
    QVBoxLayout,
    QWidget,
    QWizardPage,
)

from vmssailor.library import load_library
from vmssailor.studio.theme import C_FOG, mono_font, ui_font


class Step02Template(QWizardPage):
    def __init__(self, parent: QWidget | None = None) -> None:
        super().__init__(parent)
        self.setTitle("Paso 2 · Plantilla de buque")
        self.setSubTitle(
            "Elige una plantilla de la biblioteca curada. Las dimensiones del paso 3 "
            "se pre-rellenarán pero puedes ajustar después."
        )

        outer = QHBoxLayout(self)
        outer.setSpacing(20)

        # Left: list of templates filtered by type
        self._list = QListWidget()
        self._list.setMinimumWidth(280)
        outer.addWidget(self._list, 1)

        # Right: details
        right = QVBoxLayout()
        outer.addLayout(right, 2)

        self._name_label = QLabel("(Selecciona una plantilla)")
        self._name_label.setObjectName("title")
        self._name_label.setFont(ui_font(13))
        right.addWidget(self._name_label)

        self._meta_label = QLabel("")
        self._meta_label.setFont(mono_font(10))
        self._meta_label.setStyleSheet(f"color: {C_FOG};")
        right.addWidget(self._meta_label)

        self._desc_label = QLabel("")
        self._desc_label.setWordWrap(True)
        right.addWidget(self._desc_label)

        right.addStretch(1)

        # Hidden vessel_name field for the next step
        self._vessel_name = QLineEdit()
        self._vessel_name.hide()

        from vmssailor.studio.wizard.wizard import F_TEMPLATE_ID, F_VESSEL_NAME

        self.registerField(F_TEMPLATE_ID, self, "selected_template_id", "templateChanged")
        self.registerField(F_VESSEL_NAME, self._vessel_name)

        self._templates: dict[str, dict] = {}
        self._selected_id: str | None = None
        self._load_templates()

        self._list.currentItemChanged.connect(self._on_selection_changed)

    # ----- Property API (for QWizard field) -------------------------------

    from PySide6.QtCore import Property, Signal  # type: ignore

    templateChanged = Signal()

    def get_selected_template_id(self) -> str:
        return self._selected_id or ""

    def set_selected_template_id(self, value: str) -> None:
        self._selected_id = value
        self.templateChanged.emit()

    selected_template_id = Property(
        str, fget=get_selected_template_id, fset=set_selected_template_id, notify=templateChanged
    )

    # ----- Internals ------------------------------------------------------

    def initializePage(self) -> None:
        from vmssailor.studio.wizard.wizard import F_VESSEL_TYPE

        type_str = self.field(F_VESSEL_TYPE)
        self._refresh_list(type_str)

    def _load_templates(self) -> None:
        try:
            result = load_library()
            for v in result.vessels:
                self._templates[v.id] = {
                    "id": v.id,
                    "name": v.name,
                    "type": v.type.value,
                    "length_overall_m": v.length_overall_m,
                    "beam_max_m": v.beam_max_m,
                    "draft_m": v.draft_m,
                    "description": v.description,
                }
        except Exception:
            # Si la biblioteca falla, no rompemos el wizard.
            pass

        # Also add a "blank" template
        self._templates["__blank__"] = {
            "id": "__blank__",
            "name": "Plantilla en blanco",
            "type": "*",
            "length_overall_m": 24.0,
            "beam_max_m": 5.5,
            "draft_m": 1.8,
            "description": "Empezar desde cero, sin plantilla de buque. Defines todas las dimensiones manualmente.",
        }

    def _refresh_list(self, type_filter: str | None) -> None:
        self._list.clear()
        for tid, t in self._templates.items():
            if type_filter and t["type"] not in (type_filter, "*"):
                continue
            label = (
                f"{t['name']}\n"
                f"   {t['length_overall_m']:.1f} × {t['beam_max_m']:.1f} m"
                if tid != "__blank__"
                else t["name"]
            )
            item = QListWidgetItem(label)
            item.setData(Qt.UserRole, tid)
            self._list.addItem(item)
        if self._list.count() > 0:
            self._list.setCurrentRow(0)

    def _on_selection_changed(self, current: QListWidgetItem | None) -> None:
        if not current:
            return
        tid = current.data(Qt.UserRole)
        t = self._templates.get(tid)
        if not t:
            return
        self._selected_id = tid
        self._vessel_name.setText(t["name"])
        self._name_label.setText(t["name"])
        self._meta_label.setText(
            f"id: {t['id']}    LOA {t['length_overall_m']:.1f} m · "
            f"manga {t['beam_max_m']:.1f} m · calado {t['draft_m']:.1f} m"
        )
        self._desc_label.setText(t.get("description", "") or "(sin descripción)")
        self.templateChanged.emit()
        self.completeChanged.emit()

    def isComplete(self) -> bool:
        return self._selected_id is not None

    def get_template(self) -> dict | None:
        if self._selected_id:
            return self._templates.get(self._selected_id)
        return None