"""Generate PDF: Scanned letter FROM client (simulated scan effect)."""

import io
from pathlib import Path
from reportlab.lib.pagesizes import A4
from reportlab.lib.units import mm
from reportlab.pdfgen import canvas
from reportlab.lib.colors import HexColor

try:
    from PIL import Image, ImageFilter, ImageEnhance
    import random as _random

    HAS_PIL = True
except ImportError:
    HAS_PIL = False


def _create_clean_pdf(
    buffer, from_name, from_company, from_address, to_name, to_firm, body, date
):
    """Create a clean PDF letter."""
    c = canvas.Canvas(buffer, pagesize=A4)
    w, h = A4

    # Company header
    c.setFont("Helvetica-Bold", 14)
    c.drawString(50, h - 60, from_company)
    c.setFont("Helvetica", 9)
    y = h - 78
    for line in from_address.split(","):
        c.drawString(50, y, line.strip())
        y -= 14

    # Date
    y -= 20
    c.setFont("Helvetica", 11)
    c.drawString(50, y, date)

    # Recipient
    y -= 30
    c.drawString(50, y, f"Mr. {to_name}")
    y -= 16
    c.drawString(50, y, to_firm)
    y -= 16
    c.drawString(50, y, "Suites 3203-3207, 32/F, Edinburgh Tower, The Landmark")
    y -= 16
    c.drawString(50, y, "15 Queen's Road Central, Central, Hong Kong")

    # Body
    y -= 35
    c.setFont("Helvetica", 11)
    for para in body.split("\n\n"):
        for line_text in _wrap_text(para.strip(), 85):
            if y < 80:
                c.showPage()
                y = h - 60
                c.setFont("Helvetica", 11)
            c.drawString(50, y, line_text)
            y -= 16
        y -= 10

    # Signature area
    y -= 20
    c.drawString(50, y, "Yours sincerely,")
    y -= 40
    # Simulate a signature squiggle
    c.setStrokeColor(HexColor("#1a1a8a"))
    c.setLineWidth(1.5)
    import random

    random.seed(hash(from_name))
    sx = 50
    sy = y + 10
    c.line(sx, sy, sx + 30, sy + 8)
    c.line(sx + 30, sy + 8, sx + 50, sy - 5)
    c.line(sx + 50, sy - 5, sx + 80, sy + 3)
    c.setStrokeColor(HexColor("#000000"))

    y -= 10
    c.setFont("Helvetica-Bold", 11)
    c.drawString(50, y, from_name)
    y -= 16
    c.setFont("Helvetica", 10)
    c.drawString(50, y, from_company)

    c.save()


def _wrap_text(text, max_chars):
    """Simple word-wrap."""
    words = text.split()
    lines = []
    current = ""
    for word in words:
        if len(current) + len(word) + 1 > max_chars:
            lines.append(current)
            current = word
        else:
            current = f"{current} {word}" if current else word
    if current:
        lines.append(current)
    return lines


def generate(
    output_path: Path,
    from_name: str,
    from_company: str,
    from_address: str,
    to_name: str,
    to_firm: str,
    body: str,
    date: str,
):
    """Generate a scanned-looking PDF letter."""
    # First create a clean PDF in memory
    buf = io.BytesIO()
    _create_clean_pdf(
        buf, from_name, from_company, from_address, to_name, to_firm, body, date
    )
    buf.seek(0)

    if HAS_PIL:
        # Convert to image, degrade slightly, save back as PDF
        try:
            from pdf2image import convert_from_bytes

            images = convert_from_bytes(buf.read(), dpi=150)
            if images:
                img = images[0]
                # Add slight grey tint (paper simulation)
                enhancer = ImageEnhance.Brightness(img)
                img = enhancer.enhance(0.95)
                # Slight blur for scan effect
                img = img.filter(ImageFilter.GaussianBlur(radius=0.3))
                # Save as PDF
                img.save(str(output_path), "PDF", resolution=150)
                return
        except Exception:
            pass

    # Fallback: save clean PDF as-is
    output_path.write_bytes(buf.getvalue())