# -*- coding: utf-8 -*-
import base64
import logging
from io import BytesIO

from odoo import models, fields, api

_logger = logging.getLogger(__name__)


class FusionSaSignatureTemplate(models.Model):
    _name = 'fusion.sa.signature.template'
    _description = 'SA Mobility Signature Position Template'
    _order = 'name'

    name = fields.Char(string='Template Name', required=True)
    active = fields.Boolean(default=True)
    notes = fields.Text(string='Notes')

    sa_default_sig_page = fields.Integer(string='Default Signature Page', default=2)

    # Absolute PDF point coordinates. Y = distance from top of page.
    sa_sig_name_x = fields.Integer(string='Name X', default=105)
    sa_sig_name_y = fields.Integer(string='Name Y from top', default=97)
    sa_sig_date_x = fields.Integer(string='Date X', default=430)
    sa_sig_date_y = fields.Integer(string='Date Y from top', default=97)
    sa_sig_x = fields.Integer(string='Signature X', default=72)
    sa_sig_y = fields.Integer(string='Signature Y from top', default=68)
    sa_sig_w = fields.Integer(string='Signature Width', default=190)
    sa_sig_h = fields.Integer(string='Signature Height', default=25)

    preview_pdf = fields.Binary(
        string='Sample PDF',
        help='Upload a sample SA Mobility approval form to preview signature placement.',
        attachment=True,
    )
    preview_pdf_filename = fields.Char(string='PDF Filename')
    preview_pdf_page = fields.Integer(
        string='Preview Page', default=0,
        help='Page to render preview for. 0 = use Default Signature Page.',
    )
    preview_image = fields.Binary(
        string='Preview', readonly=True,
        compute='_compute_preview_image',
    )

    @api.depends(
        'preview_pdf', 'preview_pdf_page', 'sa_default_sig_page',
        'sa_sig_name_x', 'sa_sig_name_y',
        'sa_sig_date_x', 'sa_sig_date_y',
        'sa_sig_x', 'sa_sig_y', 'sa_sig_w', 'sa_sig_h',
    )
    def _compute_preview_image(self):
        for rec in self:
            if not rec.preview_pdf:
                rec.preview_image = False
                continue
            try:
                rec.preview_image = rec._render_preview()
            except Exception as e:
                _logger.warning("SA template preview render failed: %s", e)
                rec.preview_image = False

    def _render_preview(self):
        """Render the sample PDF page with colored markers for all signature positions."""
        self.ensure_one()
        from odoo.tools.pdf import PdfFileReader

        pdf_bytes = base64.b64decode(self.preview_pdf)
        reader = PdfFileReader(BytesIO(pdf_bytes))
        num_pages = reader.getNumPages()

        page_num = self.preview_pdf_page or self.sa_default_sig_page or 2
        page_idx = page_num - 1
        if page_idx < 0 or page_idx >= num_pages:
            return False

        try:
            from pdf2image import convert_from_bytes
        except ImportError:
            _logger.warning("pdf2image not installed")
            return False

        images = convert_from_bytes(
            pdf_bytes, first_page=page_idx + 1, last_page=page_idx + 1, dpi=150,
        )
        if not images:
            return False

        from PIL import ImageDraw, ImageFont
        img = images[0]
        draw = ImageDraw.Draw(img)

        page = reader.getPage(page_idx)
        page_w_pts = float(page.mediaBox.getWidth())
        page_h_pts = float(page.mediaBox.getHeight())
        img_w, img_h = img.size
        sx = img_w / page_w_pts
        sy = img_h / page_h_pts

        try:
            font_b = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf", 14)
            font = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", 12)
            font_sm = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", 10)
        except Exception:
            font_b = font = font_sm = ImageFont.load_default()

        def _draw_sample_text(label, x_pts, y_top_pts, color, sample_text):
            px_x = int(x_pts * sx)
            px_y = int(y_top_pts * sy)
            draw.text((px_x, px_y - 16), sample_text, fill=color, font=font_b)
            draw.text((px_x, px_y + 2), label, fill=color, font=font_sm)

        def _draw_box(label, x_pts, y_top_pts, w_pts, h_pts, color):
            px_x = int(x_pts * sx)
            px_y = int(y_top_pts * sy)
            pw = int(w_pts * sx)
            ph = int(h_pts * sy)
            for off in range(3):
                draw.rectangle(
                    [px_x - off, px_y - off, px_x + pw + off, px_y + ph + off],
                    outline=color,
                )
            draw.text((px_x + 4, px_y + 4), label, fill=color, font=font_sm)

        _draw_sample_text(
            "Name", self.sa_sig_name_x, self.sa_sig_name_y,
            'blue', "John Smith",
        )
        _draw_sample_text(
            "Date", self.sa_sig_date_x, self.sa_sig_date_y,
            'purple', "2026-02-17",
        )
        _draw_box(
            "Signature", self.sa_sig_x, self.sa_sig_y,
            self.sa_sig_w, self.sa_sig_h, 'red',
        )

        buf = BytesIO()
        img.save(buf, format='PNG')
        return base64.b64encode(buf.getvalue())

    def get_sa_coordinates(self, page_h=792):
        """Convert to ReportLab bottom-origin coordinates.

        Template stores Y as distance from TOP of page.
        ReportLab uses Y from BOTTOM.
        For text (name/date): baseline Y = page_h - y_from_top
        For signature image: drawImage Y is bottom-left corner,
            so Y = page_h - y_from_top - height
        """
        self.ensure_one()
        return {
            'name_x': self.sa_sig_name_x,
            'name_y': page_h - self.sa_sig_name_y,
            'date_x': self.sa_sig_date_x,
            'date_y': page_h - self.sa_sig_date_y,
            'sig_x': self.sa_sig_x,
            'sig_y': page_h - self.sa_sig_y - self.sa_sig_h,
            'sig_w': self.sa_sig_w,
            'sig_h': self.sa_sig_h,
        }