import io
from pathlib import Path

from PIL import Image, ImageDraw, ImageFont
from flask import current_app

from app.services.qr_service import generate_qr_for_guest
from app.utils.timezone import utc_to_local
from app.utils.paths import event_logo_folder, event_tickets_folder, event_photo_folder, event_qr_folder


TICKET_SIZE = (650, 1150)

NON_TRANSFERABLE_TEXT = (
    "Билет действителен только для указанного гостя. "
    "Передача третьим лицам запрещена."
)


def _load_logo_image(logo_path):
    """Загружает логотип: PNG/JPG через Pillow, SVG через svglib + reportlab."""
    if str(logo_path).lower().endswith(".svg"):
        try:
            from svglib.svglib import svg2rlg
            from reportlab.graphics import renderPM

            drawing = svg2rlg(str(logo_path))
            if drawing is None:
                raise ValueError("Не удалось распарсить SVG")

            # svglib может оставить нулевые размеры; подстраховываемся
            orig_width = drawing.width or 0
            orig_height = drawing.height or 0
            scale = max(orig_width, orig_height) / 1000
            if scale > 0:
                drawing.width /= scale
                drawing.height /= scale
                drawing.scale(1 / scale, 1 / scale)

            png_data = renderPM.drawToString(drawing, fmt="PNG", dpi=150)
            return Image.open(io.BytesIO(png_data)).convert("RGBA")
        except Exception as e:
            current_app.logger.warning(f"Не удалось конвертировать SVG {logo_path}: {e}")
            return None
    else:
        return Image.open(str(logo_path)).convert("RGBA")


def _draw_logo_centered(img, event, y, max_width):
    """Рисует логотип по центру, возвращает новую y-координату."""
    if not event.logo_filename:
        return y

    logo_path = event_logo_folder(event.id) / event.logo_filename
    if not logo_path.exists():
        current_app.logger.warning(f"Логотип не найден: {logo_path}")
        return y

    try:
        logo = _load_logo_image(logo_path)
        if logo is None:
            return y

        # Масштабируем по ширине
        if logo.width <= 0 or logo.height <= 0:
            current_app.logger.warning(f"Логотип имеет некорректные размеры: {logo.width}x{logo.height}")
            return y

        ratio = logo.width / logo.height
        new_width = min(max_width, logo.width)
        new_height = int(new_width / ratio)
        logo = logo.resize((new_width, new_height), Image.Resampling.LANCZOS)

        x = (TICKET_SIZE[0] - new_width) // 2
        img.paste(logo, (x, y), logo)
        return y + new_height + 25
    except Exception as e:
        current_app.logger.warning(f"Не удалось отрисовать логотип {event.logo_filename}: {e}")
        return y


def hex_to_rgb(hex_color):
    """Конвертирует HEX-цвет в кортеж RGB."""
    hex_color = hex_color.lstrip("#")
    if len(hex_color) != 6:
        return (255, 255, 255)
    return tuple(int(hex_color[i:i + 2], 16) for i in (0, 2, 4))


def _adjust_color(color, factor=0.85):
    """Затемняет или осветляет RGB-цвет."""
    rgb = color if isinstance(color, tuple) else hex_to_rgb(color)
    return tuple(min(255, max(0, int(c * factor))) for c in rgb)


def _get_font(size, style="regular"):
    """Пытается загрузить системный шрифт."""
    candidates = {
        "regular": ["calibri.ttf", "segoeui.ttf", "arial.ttf"],
        "bold": ["calibrib.ttf", "segoeuib.ttf", "arialbd.ttf"],
        "serif": ["times.ttf", "georgia.ttf", "cambria.ttf", "calibri.ttf"],
        "serif_bold": ["timesbd.ttf", "georgiab.ttf", "cambriab.ttf", "calibrib.ttf"],
    }

    for font_name in candidates.get(style, candidates["regular"]):
        font_path = Path("C:/Windows/Fonts") / font_name
        if font_path.exists():
            try:
                return ImageFont.truetype(str(font_path), size)
            except Exception:
                pass
    return ImageFont.load_default()


def _draw_text_centered(draw, text, y, width, font, fill, max_width=None):
    """Рисует текст по центру с переносом по словам."""
    if not text:
        return y

    max_width = max_width or width - 80
    words = text.split()
    lines = []
    current_line = ""

    for word in words:
        test_line = f"{current_line} {word}".strip()
        bbox = draw.textbbox((0, 0), test_line, font=font)
        if bbox[2] - bbox[0] <= max_width:
            current_line = test_line
        else:
            if current_line:
                lines.append(current_line)
            current_line = word
    if current_line:
        lines.append(current_line)

    line_height = font.size + 10
    for line in lines:
        bbox = draw.textbbox((0, 0), line, font=font)
        text_width = bbox[2] - bbox[0]
        x = (width - text_width) // 2
        draw.text((x, y), line, font=font, fill=fill)
        y += line_height

    return y


def _draw_text_left(draw, text, x, y, font, fill, max_width):
    """Рисует текст слева с переносом по словам."""
    if not text:
        return y

    words = text.split()
    lines = []
    current_line = ""

    for word in words:
        test_line = f"{current_line} {word}".strip()
        bbox = draw.textbbox((0, 0), test_line, font=font)
        if bbox[2] - bbox[0] <= max_width:
            current_line = test_line
        else:
            if current_line:
                lines.append(current_line)
            current_line = word
    if current_line:
        lines.append(current_line)

    line_height = font.size + 6
    for line in lines:
        draw.text((x, y), line, font=font, fill=fill)
        y += line_height

    return y


def _draw_info_row(draw, label, value, x, y, width, label_font, value_font, fill):
    """Рисует строку с подписью и значением по центру."""
    if not value:
        return y

    # Подпись по центру
    bbox = draw.textbbox((0, 0), label, font=label_font)
    label_width = bbox[2] - bbox[0]
    draw.text((x + (width - label_width) // 2, y), label, font=label_font, fill=fill)
    y += label_font.size + 4

    # Значение по центру
    words = value.split()
    lines = []
    current_line = ""
    for word in words:
        test_line = f"{current_line} {word}".strip()
        bbox = draw.textbbox((0, 0), test_line, font=value_font)
        if bbox[2] - bbox[0] <= width:
            current_line = test_line
        else:
            if current_line:
                lines.append(current_line)
            current_line = word
    if current_line:
        lines.append(current_line)

    line_height = value_font.size + 6
    for line in lines:
        bbox = draw.textbbox((0, 0), line, font=value_font)
        text_width = bbox[2] - bbox[0]
        draw.text((x + (width - text_width) // 2, y), line, font=value_font, fill=fill)
        y += line_height

    return y + 16


def _draw_ornament(draw, y, width, color):
    """Рисует декоративную горизонтальную линию с точками по краям."""
    margin = 100
    draw.line([(margin, y), (width - margin, y)], fill=color, width=1)
    r = 4
    draw.ellipse([margin - r, y - r, margin + r, y + r], fill=color)
    draw.ellipse([width - margin - r, y - r, width - margin + r, y + r], fill=color)


def generate_ticket_image(guest, event, output_path=None):
    """Генерирует элегантный PNG-пригласительный билет."""
    if not guest.qr_filename:
        generate_qr_for_guest(guest)

    width, height = TICKET_SIZE
    bg_color = hex_to_rgb(event.ticket_background_color or "#ffffff")
    text_color = hex_to_rgb(event.ticket_text_color or "#1a1a1a")
    accent_color = hex_to_rgb(event.ticket_accent_color or "#0d6efd")

    img = Image.new("RGB", (width, height), bg_color)
    draw = ImageDraw.Draw(img)

    # Мягкий фоновый градиент/рамка
    for i in range(20):
        alpha = int(255 * (1 - i / 40))
        c = tuple(min(255, int(bg_color[j] + (accent_color[j] - bg_color[j]) * (i / 60))) for j in range(3))
        draw.rectangle([i, i, width - 1 - i, height - 1 - i], outline=c, width=1)

    # Декоративная внешняя рамка
    draw.rectangle([22, 22, width - 22, height - 22], outline=accent_color, width=2)
    draw.rectangle([28, 28, width - 28, height - 28], outline=_adjust_color(accent_color, 1.3), width=1)

    # Шрифты
    title_font = _get_font(32, "serif_bold")
    subtitle_font = _get_font(20, "serif")
    name_font = _get_font(28, "bold")
    body_font = _get_font(17, "regular")
    label_font = _get_font(13, "regular")
    small_font = _get_font(12, "regular")

    y = 50

    # Логотип по центру сверху
    y = _draw_logo_centered(img, event, y, max_width=300)

    # Название мероприятия
    title = event.ticket_title or event.name
    y = _draw_text_centered(draw, title, y, width, title_font, text_color, max_width=width - 80)

    # Подзаголовок
    if event.ticket_subtitle:
        y += 8
        y = _draw_text_centered(draw, event.ticket_subtitle, y, width, subtitle_font, text_color, max_width=width - 80)

    y += 25
    _draw_ornament(draw, y, width, accent_color)
    y += 30

    # Приглашается
    y = _draw_text_centered(draw, "ПРИГЛАШАЕТСЯ", y, width, label_font, text_color)
    y += 12
    y = _draw_text_centered(draw, guest.build_full_name(), y, width, name_font, text_color, max_width=width - 80)
    y += 30

    # Данные гостя
    content_width = width - 120
    x_content = 60

    if guest.department:
        y = _draw_info_row(draw, "Отдел", guest.department, x_content, y, content_width, label_font, body_font, text_color)
    if guest.position:
        y = _draw_info_row(draw, "Должность", guest.position, x_content, y, content_width, label_font, body_font, text_color)
    if guest.email:
        y = _draw_info_row(draw, "Email", guest.email, x_content, y, content_width, label_font, body_font, text_color)
    if guest.phone:
        y = _draw_info_row(draw, "Телефон", guest.phone, x_content, y, content_width, label_font, body_font, text_color)

    # Инфо о мероприятии
    if event.event_date or event.location:
        y += 10
        _draw_ornament(draw, y, width, accent_color)
        y += 25
        if event.event_date:
            local_event_date = utc_to_local(event.event_date)
            date_value = local_event_date.strftime("%d.%m.%Y")
            time_value = local_event_date.strftime("%H:%M")
            y = _draw_info_row(draw, "Дата", date_value, x_content, y, content_width, label_font, body_font, text_color)
            y = _draw_info_row(draw, "Время", time_value, x_content, y, content_width, label_font, body_font, text_color)
        if event.location:
            y = _draw_info_row(draw, "Место проведения", event.location, x_content, y, content_width, label_font, body_font, text_color)

    # QR-код
    if event.ticket_show_qr:
        y += 15
        qr_path = event_qr_folder(guest.event_id) / guest.qr_filename
        if qr_path.exists():
            qr_size = 200
            qr_img = Image.open(str(qr_path)).convert("RGB")
            qr_img = qr_img.resize((qr_size, qr_size))
            x_qr = (width - qr_size) // 2
            img.paste(qr_img, (x_qr, y))
            y += qr_size + 12
            y = _draw_text_centered(draw, "QR-код для входа", y, width, small_font, text_color)

    # Фото гостя
    if event.ticket_show_photo and guest.photo_filename:
        photo_path = event_photo_folder(guest.event_id) / guest.photo_filename
        if photo_path.exists():
            photo_img = Image.open(str(photo_path)).convert("RGB")
            photo_img.thumbnail((130, 130))
            x_photo = (width - photo_img.width) // 2
            img.paste(photo_img, (x_photo, y))
            y += photo_img.height + 20

    # Дополнительный текст
    if event.ticket_body_text:
        y += 10
        y = _draw_text_centered(draw, event.ticket_body_text, y, width, small_font, text_color, max_width=width - 80)
        y += small_font.size + 10

    # Номер билета
    ticket_id = f"№ {guest.token[:8].upper()}" if not guest.token.startswith("preview") else "№ PREVIEW"
    y = max(y, height - 105)
    _draw_text_centered(draw, ticket_id, y, width, small_font, text_color)

    # Нижнее уведомление
    draw.rectangle([22, height - 65, width - 22, height - 22], fill=accent_color)
    _draw_text_centered(draw, NON_TRANSFERABLE_TEXT, height - 50, width, small_font, (255, 255, 255), max_width=width - 60)

    # Сохранение
    if output_path is None:
        tickets_folder = event_tickets_folder(event.id)
        tickets_folder.mkdir(parents=True, exist_ok=True)
        output_path = tickets_folder / f"ticket_{event.id}_{guest.token}.png"

    img.save(str(output_path), "PNG")
    return Path(output_path)


def generate_preview_ticket(event, sample_guest=None):
    """Генерирует билет для предпросмотра."""
    if sample_guest is None:
        from app.models import Guest
        sample_guest = Guest(
            event_id=event.id,
            last_name="Иванов",
            first_name="Иван",
            middle_name="Иванович",
            full_name="Иванов Иван Иванович",
            department="Отдел продаж",
            position="Менеджер",
            email="example@company.com",
            phone="+7 (999) 123-45-67",
            token="preview-token-12345",
            qr_filename=None,
        )
        from app.services.qr_service import generate_qr_for_guest
        generate_qr_for_guest(sample_guest, base_url="http://example.com")

    return generate_ticket_image(sample_guest, event)