const { Plugin } = require('obsidian');

class CsvParser {
	constructor(lines) {
		let rows = lines.split("\n").filter((l) => l.length > 0);
		this._cells = rows.map((l) => this._parseRow(l));
	}

	_parseRow(line) {
		const cells = [];
		let i = 0;
		while (i <= line.length) {
			if (i === line.length) {
				// trailing comma produced an empty final field
				break;
			}
			if (line[i] === '"') {
				// quoted field
				i++; // skip opening quote
				let value = '';
				while (i < line.length) {
					if (line[i] === '"') {
						if (i + 1 < line.length && line[i + 1] === '"') {
							// escaped double quote
							value += '"';
							i += 2;
						} else {
							// closing quote
							i++; // skip closing quote
							break;
						}
					} else {
						value += line[i];
						i++;
					}
				}
				cells.push(value);
				// skip comma after closing quote
				if (i < line.length && line[i] === ',') {
					i++;
				}
			} else {
				// unquoted field
				let end = line.indexOf(',', i);
				if (end === -1) {
					cells.push(line.substring(i));
					i = line.length;
				} else {
					cells.push(line.substring(i, end));
					i = end + 1;
				}
			}
		}
		return cells;
	}

	cells() {
		return this._cells;
	}
}

const COPY_ICON_SVG = '<svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><rect x="9" y="9" width="13" height="13" rx="2" ry="2"></rect><path d="M5 15H4a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h9a2 2 0 0 1 2 2v1"></path></svg>';

class CsvPlugin extends Plugin {
	async onload() {
		this.addStyle();
		this.registerMarkdownCodeBlockProcessor('csv', (source, el, ctx) => {
			const wrapper = el.createEl('div');
			wrapper.addClass('csv-table-wrapper');

			const table = wrapper.createEl('table');
			table.addClass('csv-table');

			let cp = new CsvParser(source);
			let allCells = cp.cells();
			let twrap = null;

			for (let rowIdx = 0; rowIdx < allCells.length; rowIdx++) {
				let row = allCells[rowIdx];
				if (twrap == null) {
					twrap = table.createEl('thead');
				} else if (twrap.nodeName == 'THEAD') {
					twrap = table.createEl('tbody');
				}

				let rowElem = twrap.createEl('tr');
				for (let colIdx = 0; colIdx < row.length; colIdx++) {
					let col = row[colIdx];
					if (rowIdx === 0) {
						// Header cell with copy button
						let td = rowElem.createEl('td');
						td.addClass('csv-table-header');
						td.createEl('span', { text: col });

						let btn = td.createEl('button');
						btn.addClass('csv-copy-btn');
						btn.setAttribute('aria-label', 'Copy column');
						btn.innerHTML = COPY_ICON_SVG;

						const ci = colIdx;
						btn.addEventListener('click', (e) => {
							e.preventDefault();
							e.stopPropagation();
							let columnText = allCells
								.map((r) => (ci < r.length ? r[ci] : ''))
								.join('\n');
							navigator.clipboard.writeText(columnText);
						});
					} else {
						rowElem.createEl('td', { text: col });
					}
				}
			}
		});
	}

	addStyle() {
		const link = document.createElement('link');
		link.rel = 'stylesheet';
		link.href = this.app.vault.adapter.getResourcePath('styles.css');
		document.head.appendChild(link);
	}
}

module.exports = CsvPlugin;