# agent_v0/lea_ui/chat_widget.py
"""
Widget de chat pour l'interface Lea.

Affiche les messages avec des bulles :
  - Utilisateur a droite (fond indigo)
  - Lea a gauche (fond blanc)

Communique avec le serveur Linux via LeaServerClient.
"""

from __future__ import annotations

import logging
from typing import List, Optional

from PyQt5.QtCore import (
    QPropertyAnimation,
    QSize,
    Qt,
    QTimer,
    pyqtSignal,
    pyqtSlot,
)
from PyQt5.QtGui import QColor, QFont, QPainter, QPainterPath, QPen
from PyQt5.QtWidgets import (
    QFrame,
    QHBoxLayout,
    QLabel,
    QLineEdit,
    QPushButton,
    QScrollArea,
    QSizePolicy,
    QVBoxLayout,
    QWidget,
)

from . import styles

logger = logging.getLogger("lea_ui.chat")


class ChatBubble(QFrame):
    """Bulle de message individuelle."""

    def __init__(
        self,
        text: str,
        is_user: bool = False,
        parent: Optional[QWidget] = None,
    ) -> None:
        super().__init__(parent)
        self._is_user = is_user

        # Style de la bulle
        if is_user:
            bg_color = styles.COLOR_BUBBLE_USER
            text_color = styles.COLOR_TEXT_ON_ACCENT
            align = Qt.AlignRight
        else:
            bg_color = styles.COLOR_BUBBLE_LEA
            text_color = styles.COLOR_TEXT
            align = Qt.AlignLeft

        self.setStyleSheet(f"""
            QFrame {{
                background-color: {bg_color};
                border-radius: {styles.BUBBLE_RADIUS}px;
                padding: {styles.PADDING}px;
                border: {"none" if is_user else f"1px solid {styles.COLOR_BORDER}"};
            }}
        """)

        layout = QVBoxLayout(self)
        layout.setContentsMargins(
            styles.PADDING, styles.PADDING // 2,
            styles.PADDING, styles.PADDING // 2,
        )

        label = QLabel(text)
        label.setWordWrap(True)
        label.setFont(QFont(styles.FONT_FAMILY, styles.FONT_SIZE_NORMAL))
        label.setStyleSheet(f"color: {text_color}; background: transparent; border: none;")
        label.setTextFormat(Qt.RichText)
        label.setOpenExternalLinks(True)
        layout.addWidget(label)

        self.setSizePolicy(QSizePolicy.Preferred, QSizePolicy.Minimum)
        self.setMaximumWidth(280)


class ChatWidget(QWidget):
    """Widget de chat complet avec zone de messages et champ de saisie.

    Signals :
        message_sent(str) : emis quand l'utilisateur envoie un message
    """

    message_sent = pyqtSignal(str)

    def __init__(self, parent: Optional[QWidget] = None) -> None:
        super().__init__(parent)
        self._messages: List[dict] = []
        self._setup_ui()

    def _setup_ui(self) -> None:
        layout = QVBoxLayout(self)
        layout.setContentsMargins(0, 0, 0, 0)
        layout.setSpacing(0)

        # Zone de messages (scrollable)
        self._scroll_area = QScrollArea()
        self._scroll_area.setWidgetResizable(True)
        self._scroll_area.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
        self._scroll_area.setStyleSheet(styles.CHAT_AREA_STYLE)

        self._messages_container = QWidget()
        self._messages_container.setObjectName("ChatContainer")
        self._messages_layout = QVBoxLayout(self._messages_container)
        self._messages_layout.setContentsMargins(
            styles.PADDING, styles.PADDING,
            styles.PADDING, styles.PADDING,
        )
        self._messages_layout.setSpacing(styles.SPACING)
        self._messages_layout.addStretch()

        self._scroll_area.setWidget(self._messages_container)
        layout.addWidget(self._scroll_area, stretch=1)

        # Separateur
        sep = QFrame()
        sep.setFrameShape(QFrame.HLine)
        sep.setStyleSheet(f"background-color: {styles.COLOR_BORDER}; max-height: 1px;")
        layout.addWidget(sep)

        # Zone de saisie
        input_layout = QHBoxLayout()
        input_layout.setContentsMargins(
            styles.PADDING, styles.SPACING,
            styles.PADDING, styles.SPACING,
        )
        input_layout.setSpacing(styles.SPACING)

        self._input = QLineEdit()
        self._input.setObjectName("ChatInput")
        self._input.setPlaceholderText("Ecrivez un message...")
        self._input.setStyleSheet(styles.INPUT_STYLE)
        self._input.returnPressed.connect(self._on_send)
        input_layout.addWidget(self._input, stretch=1)

        self._send_btn = QPushButton("Envoyer")
        self._send_btn.setObjectName("SendButton")
        self._send_btn.setStyleSheet(styles.SEND_BUTTON_STYLE)
        self._send_btn.setCursor(Qt.PointingHandCursor)
        self._send_btn.clicked.connect(self._on_send)
        input_layout.addWidget(self._send_btn)

        layout.addLayout(input_layout)

    def _on_send(self) -> None:
        """Envoyer le message saisi."""
        text = self._input.text().strip()
        if not text:
            return

        self._input.clear()
        self.add_user_message(text)
        self.message_sent.emit(text)

    # ---------------------------------------------------------------------------
    # API publique
    # ---------------------------------------------------------------------------

    def add_user_message(self, text: str) -> None:
        """Ajouter un message utilisateur (bulle a droite)."""
        self._add_bubble(text, is_user=True)

    def add_lea_message(self, text: str) -> None:
        """Ajouter un message de Lea (bulle a gauche)."""
        self._add_bubble(text, is_user=False)

    def add_system_message(self, text: str) -> None:
        """Ajouter un message systeme (centre, discret)."""
        label = QLabel(text)
        label.setFont(QFont(styles.FONT_FAMILY, styles.FONT_SIZE_SMALL))
        label.setStyleSheet(
            f"color: {styles.COLOR_TEXT_SECONDARY}; "
            f"background: transparent; padding: 4px;"
        )
        label.setAlignment(Qt.AlignCenter)
        label.setWordWrap(True)

        # Inserer avant le stretch final
        count = self._messages_layout.count()
        self._messages_layout.insertWidget(count - 1, label)
        self._scroll_to_bottom()

    def set_input_enabled(self, enabled: bool) -> None:
        """Activer/desactiver la saisie (pendant le chargement)."""
        self._input.setEnabled(enabled)
        self._send_btn.setEnabled(enabled)
        if not enabled:
            self._input.setPlaceholderText("Lea reflechit...")
        else:
            self._input.setPlaceholderText("Ecrivez un message...")

    def clear_messages(self) -> None:
        """Effacer tous les messages."""
        while self._messages_layout.count() > 1:
            item = self._messages_layout.takeAt(0)
            widget = item.widget()
            if widget:
                widget.deleteLater()
        self._messages = []

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

    def _add_bubble(self, text: str, is_user: bool) -> None:
        """Ajouter une bulle au conteneur de messages."""
        bubble = ChatBubble(text, is_user=is_user)

        # Conteneur d'alignement
        row = QHBoxLayout()
        row.setContentsMargins(0, 0, 0, 0)
        if is_user:
            row.addStretch()
            row.addWidget(bubble)
        else:
            row.addWidget(bubble)
            row.addStretch()

        # Inserer avant le stretch final
        count = self._messages_layout.count()
        wrapper = QWidget()
        wrapper.setLayout(row)
        wrapper.setStyleSheet("background: transparent;")
        self._messages_layout.insertWidget(count - 1, wrapper)

        self._messages.append({"text": text, "is_user": is_user})
        self._scroll_to_bottom()

    def _scroll_to_bottom(self) -> None:
        """Scroller vers le bas apres l'ajout d'un message."""
        QTimer.singleShot(50, lambda: (
            self._scroll_area.verticalScrollBar().setValue(
                self._scroll_area.verticalScrollBar().maximum()
            )
        ))