const fs = require('fs')
const Jimp = require('jimp')
const webp = require('webp-converter');

async function convertToWebP(inputPath) {
	try {
		if (!fs.existsSync(inputPath)) {
			throw new Error(`File doesn't exist: ${inputPath}`);
		}

		const outputWebp = inputPath.replace(/\.png$/, '.webp');

		await webp.cwebp(inputPath, outputWebp, "-lossless", "-mt");
		return outputWebp;
	} catch (err) {
		console.error(`[convertToWebP] Error: ${err.message}`);
		return null;
	}
}

async function cleanImage(inputPath, outputPath, threshold = 150) {
	if (!fs.existsSync(inputPath)) return false
	try {
		const img = await Jimp.read(inputPath)
		const { width, height } = img.bitmap

		const leftEx = Math.floor(width * 0.10)
		const rightEx = Math.floor(width * 0.90)
		const topEx = Math.floor(height * 0.10)
		const bottomEx = Math.floor(height * 0.90)

		let minX = width, minY = height, maxX = 0, maxY = 0
		const bgR = 0, bgG = 255, bgB = 0

		img.scan(0, 0, width, height, (x, y, idx) => {
			if (x < leftEx || x > rightEx || y < topEx || y > bottomEx) {
				img.bitmap.data[idx + 3] = 0
				return
			}
			const r = img.bitmap.data[idx]
			const g = img.bitmap.data[idx + 1]
			const b = img.bitmap.data[idx + 2]
			const dist = Math.sqrt((r - bgR) ** 2 + (g - bgG) ** 2 + (b - bgB) ** 2)

			if (dist < threshold) {
				img.bitmap.data[idx + 3] = 0
			} else {
				if (x < minX) minX = x
				if (y < minY) minY = y
				if (x > maxX) maxX = x
				if (y > maxY) maxY = y
			}
		})

		if (maxX > minX && maxY > minY) {
			const w = maxX - minX + 1
			const h = maxY - minY + 1
			const m = 0.05
			const exW = Math.floor(w * m)
			const exH = Math.floor(h * m)
			const cX = Math.max(0, minX - exW)
			const cY = Math.max(0, minY - exH)
			const cW = Math.min(width - cX, w + exW * 2)
			const cH = Math.min(height - cY, h + exH * 2)
			img.crop(cX, cY, cW, cH)
		}

		await img.writeAsync(outputPath)
		await convertToWebP(outputPath)

		// Cancella l'immagine originale (non-webp)
		fs.unlinkSync(inputPath)

		return true
	} catch (e) {
		console.error(`[cleanImage] Error: ${e}`)
		return false
	}
}

exports('cleanImage', cleanImage);