"""Side-effect-free HTML preview generation for render manifests.""" from __future__ import annotations from dataclasses import dataclass from html import escape from autoshorts.ideas.candidate import ValidationResult from autoshorts.rendering.manifest import RenderManifest, validate_render_manifest @dataclass(frozen=True) class RenderPreview: script_id: str title: str preview_type: str html: str side_effects: tuple[str, ...] = () external_calls: tuple[str, ...] = () def _is_blank(value: str) -> bool: return not (value or "").strip() def _timeline_row(index: int, item) -> str: time_range = f"{item.start_seconds}–{item.end_seconds}s" return "".join( ( '
', f"

{index:02d}. {escape(item.scene_purpose)}

", f"

Time: {escape(time_range)}

", f"

Asset mode: {escape(item.asset_mode)}

", f"

Motion: {escape(item.motion_instruction)}

", f"

Caption: {escape(item.caption_layer.text)}

", f"

Label: {escape(item.label_layer.text)}

", f"

Placeholder: {escape(item.placeholder_asset_path)}

", "
", ) ) def build_html_preview(manifest: RenderManifest) -> RenderPreview: """Build an inspectable HTML timeline preview without rendering media.""" validation = validate_render_manifest(manifest) if not validation.is_valid: raise ValueError("; ".join(validation.errors)) settings = manifest.settings rows = "\n".join(_timeline_row(index, item) for index, item in enumerate(manifest.timeline, start=1)) html = f""" {escape(manifest.title)} — render preview

{escape(manifest.title)}

Script: {escape(manifest.script_id)}

Format: {settings.width}x{settings.height}, {settings.fps}fps

Text policy: captions and labels are renderer-owned; no generated text inside assets.

{rows}
""" return RenderPreview( script_id=manifest.script_id, title=manifest.title, preview_type="html_timeline", html=html, side_effects=(), external_calls=(), ) def validate_render_preview(preview: RenderPreview) -> ValidationResult: errors: list[str] = [] if _is_blank(preview.script_id): errors.append("script_id is required") if _is_blank(preview.title): errors.append("title is required") if preview.preview_type != "html_timeline": errors.append("preview_type must be html_timeline") if _is_blank(preview.html): errors.append("html is required") if "