/**
 * Files Provider
 *
 * Lists workspace files using fd (fast) with fallback to find.
 * Supports multi-select and frecency tracking.
 */

import { execSync } from "node:child_process";
import { resolve } from "node:path";
import type { Theme } from "@mariozechner/pi-coding-agent";
import type { TelescopeProvider } from "../types.js";
import { copyToClipboard } from "../clipboard.js";

function hasBinary(name: string): boolean {
	try {
		execSync(`which ${name}`, { stdio: "ignore" });
		return true;
	} catch {
		return false;
	}
}

const useFd = hasBinary("fd");

export function listFiles(cwd: string): string[] {
	try {
		const cmd = useFd
			? "fd --type f --hidden --follow --exclude .git --exclude node_modules --exclude .venv --exclude dist --exclude build --max-results 10000"
			: "find . -type f -not -path '*/.git/*' -not -path '*/node_modules/*' -not -path '*/.venv/*' -not -path '*/dist/*' -not -path '*/build/*' | head -10000";

		const output = execSync(cmd, {
			encoding: "utf-8",
			cwd,
			timeout: 10_000,
			maxBuffer: 10 * 1024 * 1024,
		});

		let lines = output.split("\n").filter(Boolean);

		// Normalize: strip cwd prefix and leading ./
		const prefix = cwd.endsWith("/") ? cwd : cwd + "/";
		lines = lines.map((l) => {
			if (l.startsWith(prefix)) return l.slice(prefix.length);
			if (l.startsWith("./")) return l.slice(2);
			return l;
		});

		return lines.sort();
	} catch {
		return [];
	}
}

export function createFilesProvider(cwd: string): TelescopeProvider<string> {
	return {
		name: "files",
		icon: "📄",
		description: "Workspace files",

		load() {
			return listFiles(cwd);
		},

		getSearchText(item) {
			return item;
		},

		getDisplayText(item, theme, highlighted) {
			return highlighted ?? item;
		},

		async onSelect(item, ctx) {
			ctx.ui.pasteToEditor(`@${item}`);
		},

		async onMultiSelect(items, ctx) {
			ctx.ui.pasteToEditor(items.map((i) => `@${i}`).join(" "));
		},

		getPreview(item) {
			return [`__FILE__:${resolve(cwd, item)}`];
		},

		getFrecencyKey(item) {
			return item;
		},

		actions: [
			{ key: "c", label: "Copy path", description: "Copy file path to clipboard" },
			{ key: "i", label: "Insert content", description: "Paste file content into editor" },
		],

		async onAction(actionKey, items, ctx) {
			if (actionKey === "c") {
				copyToClipboard(items.join("\n"));
			} else if (actionKey === "i") {
				const { readFileSync } = await import("node:fs");
				for (const item of items) {
					try {
						const content = readFileSync(resolve(cwd, item), "utf-8");
						ctx.ui.pasteToEditor(content);
					} catch {}
				}
			}
		},
	};
}