Files
cinema-display/server/movie_posters/lib/common.js
2025-10-09 22:53:49 +02:00

284 lines
11 KiB
JavaScript

import axios from "axios";
import shuffleArray from "shuffle-array";
import {createCanvas, loadImage} from "canvas";
const TMDB_API_BASE_URL = "https://api.themoviedb.org/3";
const TMDB_IMAGE_BASE_URL = "https://image.tmdb.org/t/p/original";
/**
* Fetches trending movie poster paths from TMDB.
* @param {string} apiKey - The TMDB API key.
* @param {string} language - The language for the movie results (e.g., 'de-DE').
* @returns {Promise<string[]>} A promise that resolves to an array of poster image URLs.
* @throws {Error} If the API request fails or no results are found.
*/
async function fetchTrendingMoviePosters(apiKey, language) {
const url = `${TMDB_API_BASE_URL}/trending/movie/week?language=${language}`;
try {
const response = await axios.get(url, {
headers: {
'Authorization': `Bearer ${apiKey}`,
'Content-Type': 'application/json',
'Accept': 'application/json',
'User-Agent': 'Movie Posters Service (v1.0.0)'
}
});
if (!response.data || !response.data.results || response.data.results.length === 0) {
throw new Error("No trending movies found from TMDB.");
}
const posterUrls = response.data.results
.filter(item => item.poster_path)
.map(item => `${TMDB_IMAGE_BASE_URL}${item.poster_path}`);
if (posterUrls.length === 0) {
throw new Error("No valid poster paths found in the trending movies results.");
}
return posterUrls;
} catch (error) {
console.error("Error fetching data from TMDB:", error.message);
if (axios.isAxiosError(error) && error.response) {
console.error("TMDB API Response Status:", error.response.status);
console.error("TMDB API Response Data:", error.response.data);
throw new Error(`Failed to fetch trending movies from TMDB: ${error.response.statusText || error.message}`);
}
throw error;
}
}
/**
* Konvertiert einen RGBA8888-Pixelbuffer in einen RGB565 Little-Endian Buffer.
* @param {Uint8ClampedArray} rgbaBuffer - Der Eingabebuffer (R, G, B, A, R, G, B, A, ...)
* @param {number} width - Bildbreite
* @param {number} height - Bildhöhe
* @returns {Buffer} Ein Buffer mit RGB565-Daten (2 Bytes pro Pixel, Little Endian).
*/
function convertRgbaToRgb565(rgbaBuffer, width, height) {
const pixelCount = width * height;
const rgb565Buffer = Buffer.alloc(pixelCount * 2);
for (let i = 0; i < pixelCount; i++) {
const r = rgbaBuffer[i * 4 + 0];
const g = rgbaBuffer[i * 4 + 1];
const b = rgbaBuffer[i * 4 + 2];
const r5 = (r >> 3) & 0x1F;
const g6 = (g >> 2) & 0x3F;
const b5 = (b >> 3) & 0x1F;
const rgb565Value = (r5 << 11) | (g6 << 5) | b5;
rgb565Buffer.writeUInt16LE(rgb565Value, i * 2);
}
return rgb565Buffer;
}
/**
* Draws images horizontally onto the canvas, scaling and centering them.
* @param {CanvasRenderingContext2D} ctx - The canvas rendering context.
* @param {string[]} imageUrls - Array of image URLs to draw.
* @param {number} count - The number of images to draw.
* @param {number} canvasWidth - The width of the canvas.
* @param {number} canvasHeight - The height of the canvas.
*/
async function drawHorizontalPosters(ctx, imageUrls, count, canvasWidth, canvasHeight) {
const imageWidth = canvasWidth / count;
for (let i = 0; i < count; i++) {
if (!imageUrls[i]) continue;
try {
const image = await loadImage(imageUrls[i]);
const scaledHeight = image.height * (imageWidth / image.width);
const yPos = (canvasHeight - scaledHeight) / 2;
ctx.drawImage(image, imageWidth * i, yPos, imageWidth, scaledHeight);
} catch (error) {
console.error(`Error loading or drawing image ${i} (${imageUrls[i]}):`, error.message);
ctx.fillStyle = 'grey';
ctx.fillRect(imageWidth * i, 0, imageWidth, canvasHeight);
ctx.fillStyle = 'white';
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';
ctx.fillText('Error', imageWidth * i + imageWidth / 2, canvasHeight / 2);
}
}
}
/**
* Draws images vertically onto the canvas, scaling and centering them.
* @param {CanvasRenderingContext2D} ctx - The canvas rendering context.
* @param {string[]} imageUrls - Array of image URLs to draw.
* @param {number} count - The number of images to draw.
* @param {number} canvasWidth - The width of the canvas.
* @param {number} canvasHeight - The height of the canvas.
*/
async function drawVerticalPosters(ctx, imageUrls, count, canvasWidth, canvasHeight) {
const imageHeight = canvasHeight / count;
for (let i = 0; i < count; i++) {
if (!imageUrls[i]) continue;
try {
const image = await loadImage(imageUrls[i]);
const scaledWidth = image.width * (imageHeight / image.height);
const xPos = (canvasWidth - scaledWidth) / 2;
ctx.drawImage(image, xPos, imageHeight * i, scaledWidth, imageHeight);
} catch (error) {
console.error(`Error loading or drawing image ${i} (${imageUrls[i]}):`, error.message);
ctx.fillStyle = 'grey';
ctx.fillRect(0, imageHeight * i, canvasWidth, imageHeight);
ctx.fillStyle = 'white';
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';
ctx.fillText('Error', canvasWidth / 2, imageHeight * i + imageHeight / 2);
}
}
}
/**
* Generates the final output buffer or JSON based on requested format.
* @param {Canvas} canvas - The canvas object.
* @param {CanvasRenderingContext2D} ctx - The canvas rendering context.
* @param {'png' | 'jpeg'} imageFormat - The desired image format ('png' or 'jpeg').
* @param {'image' | 'lvgl' | 'lvgl_binary'} outputType - The desired output type ('image' or 'lvgl').
* @returns {{contentType: string, data: Buffer | string}} An object containing the content type and the output data (Buffer for image, string for LVGL JSON).
* @throws {Error} If an invalid format or output type is provided.
*/
function generateOutput(canvas, ctx, imageFormat, outputType) {
switch (outputType) {
case 'lvgl_binary': {
const rawRgbaData = ctx.getImageData(0, 0, canvas.width, canvas.height).data;
const rgb565Buffer = convertRgbaToRgb565(rawRgbaData, canvas.width, canvas.height);
return {
contentType: 'application/octet-stream',
contentDisposition: 'attachment; filename="image.bin"',
data: rgb565Buffer
}
}
case 'lvgl': {
const rawRgbaData = ctx.getImageData(0, 0, canvas.width, canvas.height).data;
const rgb565Buffer = convertRgbaToRgb565(rawRgbaData, canvas.width, canvas.height);
const lvglColorFormat = 'LV_COLOR_FORMAT_RGB565';
const bytesPerPixel = 2;
const dataSize = canvas.width * canvas.height * bytesPerPixel;
let cArrayString = `const uint8_t image_data_map[${dataSize}] = {`;
for (let i = 0; i < rgb565Buffer.length; i++) {
cArrayString += '0x' + rgb565Buffer[i].toString(16).padStart(2, '0').toUpperCase();
if (i < rgb565Buffer.length - 1) {
cArrayString += ', ';
}
}
cArrayString += '};';
const result = {
width: canvas.width,
height: canvas.height,
colorFormat: lvglColorFormat,
pixelFormat: 'RGB565',
data_size: dataSize,
c_array: cArrayString
};
return {
contentType: 'application/json',
data: JSON.stringify(result, null, 2)
};
}
case 'image': {
let buffer;
let contentType;
switch (imageFormat) {
case 'jpeg':
buffer = canvas.toBuffer('image/jpeg');
contentType = 'image/jpeg';
break;
case 'png':
buffer = canvas.toBuffer('image/png');
contentType = 'image/png';
break;
default:
console.warn(`Invalid image format requested: ${imageFormat}. Defaulting to PNG.`);
buffer = canvas.toBuffer('image/png');
contentType = 'image/png';
}
return {contentType, data: buffer};
}
default:
throw new Error(`Invalid output type specified: ${outputType}`);
}
}
/**
* Creates a composite poster image from trending movie posters.
*
* @param {object} req - Express request object.
* @param {object} res - Express response object.
* @param {number} width - Desired width of the final poster.
* @param {number} height - Desired height of the final poster.
* @param {number} count - Number of movie posters to include.
* @param {'horizontal' | 'vertical'} orientation - Layout orientation of the posters.
* @param {boolean} shuffleImages - Whether to shuffle the fetched posters.
* @param {string} backgroundColor - Background color for the canvas (hex code).
* @param {'png' | 'jpeg'} format - Output image format (if output is 'image').
* @param {string} language - Language for fetching movie posters (e.g., 'de-DE').
* @param {'image' | 'lvgl'} output - Desired output type.
*/
export async function createPoster(req, res, width, height, count, orientation, shuffleImages, backgroundColor, format, language, output) {
const apiKey = process.env.TMDB_API_KEY || req.header("x-api-key");
if (!apiKey) {
return res.status(401).send({error: "API key is missing. Provide it via x-api-key header or TMDB_API_KEY environment variable."});
}
try {
let imageUrls = await fetchTrendingMoviePosters(apiKey, language);
if (imageUrls.length < count) {
console.warn(`Warning: Fetched ${imageUrls.length} posters, but ${count} were requested. Repeating posters.`);
const originalUrls = [...imageUrls];
while (imageUrls.length < count) {
imageUrls.push(...originalUrls.slice(0, count - imageUrls.length));
}
}
if (shuffleImages) {
shuffleArray(imageUrls);
}
const selectedImageUrls = imageUrls.slice(0, count);
const canvas = createCanvas(width, height);
const ctx = canvas.getContext('2d', {pixelFormat: 'RGB24'});
ctx.fillStyle = backgroundColor;
ctx.fillRect(0, 0, canvas.width, canvas.height);
if (orientation === 'horizontal') {
await drawHorizontalPosters(ctx, selectedImageUrls, count, canvas.width, canvas.height);
} else if (orientation === 'vertical') {
await drawVerticalPosters(ctx, selectedImageUrls, count, canvas.width, canvas.height);
} else {
throw new Error(`Invalid orientation specified: ${orientation}`);
}
const {contentType, data, contentDisposition} = generateOutput(canvas, ctx, format, output);
if (contentDisposition) {
res.setHeader('Content-Disposition', contentDisposition);
}
res.status(200).type(contentType).end(data);
} catch (error) {
console.error("Error creating poster:", error.message);
res.status(500).send({error: `Failed to create poster: ${error.message}`});
}
}