Initial commit

app/pdf.py

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+"""PDF rendering of a generated puzzle (A4 portrait, single page)."""
+
+from __future__ import annotations
+
+import io
+from typing import Iterable
+
+from reportlab.lib.pagesizes import A4
+from reportlab.lib.units import mm
+from reportlab.pdfbase.pdfmetrics import stringWidth
+from reportlab.pdfgen import canvas
+
+from .generator import Puzzle
+
+PAGE_W, PAGE_H = A4
+MARGIN = 18 * mm
+
+TITLE_FONT = "Helvetica-Bold"
+TITLE_SIZE = 24
+
+OPTIONS_FONT = "Helvetica"
+OPTIONS_SIZE = 10
+
+GRID_FONT = "Courier-Bold"
+
+LIST_HEADING_FONT = "Helvetica-Bold"
+LIST_HEADING_SIZE = 14
+LIST_ENTRY_FONT_BOLD = "Helvetica-Bold"
+LIST_ENTRY_FONT_LIGHT = "Helvetica"
+LIST_ENTRY_SIZE = 11
+
+
+def _column_count(n: int) -> int:
+    if n <= 8:
+        return 2
+    if n <= 18:
+        return 3
+    return 4
+
+
+def _wrap_columns(items: list[tuple], cols: int) -> list[list[tuple]]:
+    """Lay items out top-to-bottom, then left-to-right, in `cols` columns."""
+    rows = (len(items) + cols - 1) // cols
+    columns: list[list[tuple]] = [[] for _ in range(cols)]
+    for i, item in enumerate(items):
+        columns[i // rows].append(item)
+    return columns
+
+
+def _grid_geometry(grid_size: int, available_w: float, available_h: float
+                   ) -> tuple[float, float]:
+    """Choose (font_size, cell_size) so a `grid_size` x `grid_size` grid
+    fits comfortably in the available box."""
+    # Cell size driven by whichever dimension is tighter, with padding.
+    target_cell = min(available_w, available_h) / grid_size
+    cell = min(target_cell, 14 * mm)  # cap so 5x5 isn't comically huge
+    cell = max(cell, 5 * mm)
+    font_size = cell * 0.7
+    return font_size, cell
+
+
+def render_puzzle(puzzle: Puzzle, title: str) -> bytes:
+    buf = io.BytesIO()
+    c = canvas.Canvas(buf, pagesize=A4)
+
+    # Title
+    c.setFont(TITLE_FONT, TITLE_SIZE)
+    title_y = PAGE_H - MARGIN - TITLE_SIZE
+    c.drawCentredString(PAGE_W / 2, title_y, title)
+
+    # Active option labels under the title (only when extras are enabled).
+    options_y = title_y
+    labels = puzzle.option_labels
+    if labels:
+        options_y = title_y - TITLE_SIZE * 0.7
+        c.setFont(OPTIONS_FONT, OPTIONS_SIZE)
+        c.setFillGray(0.35)
+        c.drawCentredString(PAGE_W / 2, options_y,
+                            "  ·  ".join(s.upper() for s in labels))
+        c.setFillGray(0)
+
+    # Reserve space for word list at the bottom; estimate from entry count.
+    placed = puzzle.placements
+    cols = _column_count(len(placed)) if placed else 2
+    rows_per_col = (len(placed) + cols - 1) // cols if placed else 0
+    list_line_height = LIST_ENTRY_SIZE * 1.5
+    list_block_h = LIST_HEADING_SIZE * 2 + rows_per_col * list_line_height
+    list_block_h = max(list_block_h, 30 * mm)
+
+    grid_top = (options_y if labels else title_y) - 8 * mm
+    grid_bottom = MARGIN + list_block_h + 6 * mm
+    available_h = grid_top - grid_bottom
+    available_w = PAGE_W - 2 * MARGIN
+
+    grid_size = puzzle.size
+    font_size, cell = _grid_geometry(grid_size, available_w, available_h)
+    grid_w = grid_size * cell
+    grid_h = grid_size * cell
+    origin_x = (PAGE_W - grid_w) / 2
+    origin_y = grid_top - grid_h  # top of grid sits at grid_top
+
+    c.setFont(GRID_FONT, font_size)
+    for r in range(grid_size):
+        for col_idx in range(grid_size):
+            ch = puzzle.grid[r][col_idx]
+            x = origin_x + col_idx * cell + cell / 2
+            # Top row in the grid array should print at the top of the grid box.
+            y = origin_y + (grid_size - 1 - r) * cell + (cell - font_size) / 2
+            c.drawCentredString(x, y, ch)
+
+    # Word list
+    list_top = grid_bottom - 2 * mm
+    c.setFont(LIST_HEADING_FONT, LIST_HEADING_SIZE)
+    c.drawCentredString(PAGE_W / 2, list_top, "Find these words")
+
+    entries: list[tuple[str, str]] = []
+    for p in placed:
+        prefix_text = ""
+        if p.word.stripped_prefixes:
+            prefix_text = " (" + " ".join(p.word.stripped_prefixes) + ")"
+        entries.append((p.word.grid, prefix_text))
+
+    if entries:
+        column_lists = _wrap_columns(entries, cols)
+        col_w = available_w / cols
+        list_y_start = list_top - LIST_HEADING_SIZE - 4 * mm
+        for col_idx, items in enumerate(column_lists):
+            x = MARGIN + col_idx * col_w
+            for i, (grid_form, prefix) in enumerate(items):
+                y = list_y_start - i * list_line_height
+                c.setFont(LIST_ENTRY_FONT_BOLD, LIST_ENTRY_SIZE)
+                c.drawString(x, y, grid_form)
+                if prefix:
+                    bold_w = stringWidth(grid_form, LIST_ENTRY_FONT_BOLD,
+                                         LIST_ENTRY_SIZE)
+                    c.setFont(LIST_ENTRY_FONT_LIGHT, LIST_ENTRY_SIZE)
+                    c.setFillGray(0.4)
+                    c.drawString(x + bold_w, y, prefix)
+                    c.setFillGray(0)
+
+    c.showPage()
+    c.save()
+    return buf.getvalue()