/* global jQuery, prR2 */
/**
 * R2 Media Manager — admin JS.
 *
 * Drives batch loops for migrate-to-R2 and remove-local-files operations.
 * Each loop fires one AJAX request, waits for the response, updates the
 * progress bar, then fires the next request — until the server signals done=true
 * or the user clicks Pause.
 *
 * Also handles: Test R2 Connection button, Clear Log button.
 */
(function ($) {
	'use strict';

	// ── Batch runner ──────────────────────────────────────────────────────────

	/**
	 * Run one batch of an AJAX operation and schedule the next.
	 *
	 * @param {string} action    WP AJAX action name.
	 * @param {string} nonce     Nonce string from wp_localize_script.
	 * @param {Object} state     Mutable state: { processed, succeeded, failed, paused }.
	 * @param {Object} ui        jQuery element refs: $btn, $pauseBtn, $bar, $status.
	 * @param {string} countKey  'succeeded' | 'removed' — key to read from response.
	 * @param {string} failKey   'failed'    | 'skipped'.
	 */
	function runBatch(action, nonce, state, ui, countKey, failKey) {
		if (state.paused) {
			ui.$status.text('Paused. Click the button again to resume.');
			ui.$btn.prop('disabled', false).text(ui.$btn.data('resume-label'));
			ui.$pauseBtn.hide();
			return;
		}

		$.post(prR2.ajaxUrl, {
			action:     action,
			nonce:      nonce,
			batch_size: prR2.batchSize,
		})
		.done(function (res) {
			if (!res.success) {
				showNotice('error', 'Error: ' + (res.data ? res.data.message : 'Unknown error.'));
				ui.$btn.prop('disabled', false);
				ui.$pauseBtn.hide();
				return;
			}

			var d = res.data;
			state.processed += d.processed;
			state.succeeded += (d[countKey] || 0);
			state.failed    += (d[failKey]   || 0);

			// remaining is the count left AFTER this batch.
			var total = state.processed + d.remaining;
			var pct   = total > 0 ? Math.round((state.processed / total) * 100) : 100;
			ui.$bar.val(pct);
			ui.$status.text(
				'Processed ' + state.processed + ' of ' + total +
				' — success: ' + state.succeeded +
				(state.failed ? ', failed/skipped: ' + state.failed : '')
			);

			if (d.done) {
				ui.$status.text(
					'Done! ✓  Succeeded: ' + state.succeeded +
					(state.failed ? '  Failed/skipped: ' + state.failed : '')
				);
				ui.$btn.prop('disabled', true);
				ui.$pauseBtn.hide();
				// Reload after 1.5 s so the status table refreshes.
				setTimeout(function () { window.location.reload(); }, 1500);
				return;
			}

			runBatch(action, nonce, state, ui, countKey, failKey);
		})
		.fail(function () {
			ui.$status.text('Network error — operation paused. Retry by clicking the button.');
			ui.$btn.prop('disabled', false).text(ui.$btn.data('resume-label'));
			ui.$pauseBtn.hide();
		});
	}

	// ── Wire up Migrate button ────────────────────────────────────────────────

	$('#pr-r2-btn-migrate').on('click', function () {
		var $btn = $(this);
		var state = { processed: 0, succeeded: 0, failed: 0, paused: false };
		var ui = {
			$btn:      $btn,
			$pauseBtn: $('#pr-r2-btn-migrate-pause'),
			$bar:      $('#pr-r2-migrate-bar'),
			$status:   $('#pr-r2-migrate-status'),
		};

		$btn.data('resume-label', 'Resume migration').prop('disabled', true);
		ui.$pauseBtn.show();
		$('#pr-r2-migrate-progress').show();
		ui.$bar.val(0);
		ui.$status.text('Starting migration…');

		runBatch('pr_r2_migrate_batch', prR2.nonceMigrate, state, ui, 'succeeded', 'failed');
	});

	$('#pr-r2-btn-migrate-pause').on('click', function () {
		// Signal the batch runner to stop after the current in-flight request.
		var state = $('#pr-r2-btn-migrate').data('batchState');
		if (state) { state.paused = true; }
	});

	// Re-wire so the button can resume (state persists in data).
	// Simpler: just reload the page — already-offloaded items are excluded by the query.

	// ── Wire up Remove Local button ───────────────────────────────────────────

	$('#pr-r2-btn-remove').on('click', function () {
		var $btn = $(this);
		var state = { processed: 0, succeeded: 0, failed: 0, paused: false };
		var ui = {
			$btn:      $btn,
			$pauseBtn: $('#pr-r2-btn-remove-pause'),
			$bar:      $('#pr-r2-remove-bar'),
			$status:   $('#pr-r2-remove-status'),
		};

		$btn.data('resume-label', 'Resume removal').prop('disabled', true);
		ui.$pauseBtn.show();
		$('#pr-r2-remove-progress').show();
		ui.$bar.val(0);
		ui.$status.text('Starting local-file removal…');

		runBatch('pr_r2_remove_local_batch', prR2.nonceRemove, state, ui, 'removed', 'skipped');
	});

	$('#pr-r2-btn-remove-pause').on('click', function () {
		var state = $('#pr-r2-btn-remove').data('batchState');
		if (state) { state.paused = true; }
	});

	// ── Test Connection ───────────────────────────────────────────────────────

	$('#pr-r2-btn-test').on('click', function () {
		var $btn    = $(this);
		var $result = $('#pr-r2-test-result');
		$btn.prop('disabled', true);
		$result.css('color', '#555').text('Testing…');

		$.post(prR2.ajaxUrl, { action: 'pr_r2_test_connection', nonce: prR2.nonceTest })
		.done(function (res) {
			if (res.success) {
				$result.css('color', '#090').text('✓ ' + res.data.message);
			} else {
				$result.css('color', '#c00').text('✗ ' + (res.data ? res.data.message : 'Failed.'));
			}
		})
		.fail(function () {
			$result.css('color', '#c00').text('✗ Network error.');
		})
		.always(function () { $btn.prop('disabled', false); });
	});

	// ── Clear Log ─────────────────────────────────────────────────────────────

	$('#pr-r2-btn-clear-log').on('click', function () {
		if (!window.confirm('Clear all log entries?')) { return; }
		var $btn = $(this);
		$btn.prop('disabled', true);

		$.post(prR2.ajaxUrl, { action: 'pr_r2_clear_log', nonce: prR2.nonceClearLog })
		.done(function (res) {
			if (res.success) {
				$('#pr-r2-log-tbody').closest('table').replaceWith('<p>Log cleared.</p>');
			} else {
				showNotice('error', 'Could not clear log.');
			}
		})
		.always(function () { $btn.prop('disabled', false); });
	});

	// ── Utility ───────────────────────────────────────────────────────────────

	function showNotice(type, msg) {
		var cls = type === 'error' ? 'notice-error' : 'notice-success';
		$('#pr-r2-notice').html(
			'<div class="notice ' + cls + ' is-dismissible"><p>' + msg + '</p></div>'
		);
	}

}(jQuery));