import { CustomEditor, type ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { Key, matchesKey, truncateToWidth, visibleWidth } from "@earendil-works/pi-tui";

class AdaptiveMultilineEditor extends CustomEditor {
	handleInput(data: string): void {
		if (matchesKey(data, Key.ctrl("u"))) {
			const text = this.getText();
			if (text.length > 0) {
				// killRing is a private Editor field, not public API; stock ctrl+y/alt+y read from
				// this same instance, so pushing here makes them paste the whole cut buffer.
				(this as unknown as { killRing: { push(text: string, opts: { prepend: boolean; accumulate?: boolean }): void } }).killRing.push(text, { prepend: true, accumulate: false });
				this.setText("");
			}
			return;
		}

		const explicitSubmit = matchesKey(data, Key.super("enter")) || matchesKey(data, Key.ctrl("enter"));
		if (explicitSubmit) {
			if (this.isShowingAutocomplete()) super.handleInput("\x1b");
			super.handleInput("\r");
			return;
		}

		if (matchesKey(data, Key.enter) && this.getText().includes("\n") && !this.isShowingAutocomplete()) {
			super.handleInput("\n");
			return;
		}

		super.handleInput(data);
	}

	render(width: number): string[] {
		const lines = super.render(width);
		if (!this.getText().includes("\n") || lines.length === 0) return lines;

		const label = " MULTILINE · ⌘↵ send ";
		const last = lines.length - 1;
		if (visibleWidth(lines[last]!) >= label.length) {
			lines[last] = truncateToWidth(lines[last]!, width - label.length, "") + label;
		}
		return lines;
	}
}

export default function (pi: ExtensionAPI) {
	pi.on("session_start", (_event, ctx) => {
		if (ctx.mode !== "tui") return;
		ctx.ui.setEditorComponent((tui, theme, keybindings) => new AdaptiveMultilineEditor(tui, theme, keybindings));
	});
}