Files
folkugat-web/folkugat_web/services/lilypond.py
2025-04-05 15:10:56 +02:00

90 lines
3.5 KiB
Python

import asyncio
import dataclasses
import itertools
import os
import re
from pathlib import Path
from typing import Literal
import aiofiles
from folkugat_web.model.lilypond import (LyricsColumn, LyricsParagraph,
LyricsText, RenderError)
from folkugat_web.model.temes import Tema
from folkugat_web.services import files as files_service
from folkugat_web.templates import templates
SCORE_BEGINNING = "% --- SCORE BEGINNING --- %"
RenderFormat = Literal["png"] | Literal["pdf"]
def source_to_single_score(source: str, tema: Tema) -> str:
if tema.lyrics:
lyrics_text = build_lyrics(tema.lyrics[0].content)
else:
lyrics_text = None
return templates.get_template("lilypond/single_score.ly").render(
score_beginning=SCORE_BEGINNING,
score_source=source,
tema=tema,
lyrics_text=lyrics_text,
)
async def render(source: str, fmt: RenderFormat, output_filename: Path | None = None) -> tuple[Path | None, list[RenderError]]:
input_filename = files_service.create_tmp_filename(extension=".ly")
async with aiofiles.open(input_filename, "w") as f:
_ = await f.write(source)
output_filename = output_filename or files_service.create_tmp_filename()
if fmt == "png":
proc = await asyncio.create_subprocess_exec(
"lilypond", "--png", "-o", output_filename, input_filename,
stdout=asyncio.subprocess.PIPE,
stderr=asyncio.subprocess.PIPE,
)
else:
proc = await asyncio.create_subprocess_exec(
"lilypond", "-o", output_filename, input_filename,
stdout=asyncio.subprocess.PIPE,
stderr=asyncio.subprocess.PIPE,
)
_stdout, stderr = await proc.communicate()
if proc.returncode:
esc_input_filename = re.escape(str(input_filename))
error_re = re.compile(rf"{esc_input_filename}:(?P<line>\d+):(?P<pos>\d+): error: (?P<error>.*)$")
error_matches = filter(None, map(error_re.match, stderr.decode("utf-8").splitlines()))
errors = map(lambda m: RenderError.from_dict(m.groupdict()), error_matches)
line_offset = source.splitlines().index(SCORE_BEGINNING) + 1
errors_offset = [dataclasses.replace(e, line=e.line - line_offset) for e in errors if e.line > line_offset]
return None, errors_offset
if fmt == "png":
# Check if the output generated multiple pages
pages = sorted(output_filename.parent.rglob(f"{output_filename.name}*.png"))
if len(pages) > 1:
output_filename = pages[0]
for page in pages[1:]:
os.remove(page)
else:
output_filename = output_filename.with_suffix(".png")
elif fmt == "pdf":
output_filename = output_filename.with_suffix(".pdf")
return output_filename, []
def build_lyrics(text: str, max_cols: int = 2, min_pars: int = 2) -> LyricsText:
paragraphs = [LyricsParagraph(lines=par_str.splitlines()) for par_str in text.split("\n\n")]
n_cols = next(filter(lambda nc: len(paragraphs) // nc >= min_pars, range(max_cols, 0, -1)), 1)
n_long_cols = len(paragraphs) % n_cols
pars_per_col = [len(paragraphs) // n_cols + 1] * n_long_cols + [len(paragraphs) // n_cols] * (n_cols - n_long_cols)
acc_pars_per_col = [0] + list(itertools.accumulate(pars_per_col))
return LyricsText(columns=[
LyricsColumn(paragraphs=paragraphs[acc_pars_per_col[i]:acc_pars_per_col[i+1]])
for i in range(n_cols)
])