<?php
/**
 * Settings page.
 *
 * @package Kayvandra\MarginBeacon
 */

declare(strict_types=1);

namespace Kayvandra\MarginBeacon\Admin\Settings;

use Kayvandra\MarginBeacon\Admin\Navigation\Tabs;
use Kayvandra\MarginBeacon\Application\Cost\CanonicalCostSource;
use Kayvandra\MarginBeacon\Application\Threshold\ThresholdProfile;
use Kayvandra\MarginBeacon\Support\Capabilities;
use Kayvandra\MarginBeacon\Support\Constants;

/**
 * Global thresholds and cost settings (Free).
 */
final class SettingsPage {

	/**
	 * Register POST handlers only (menu owned by AdminApp tabs).
	 *
	 * @return void
	 */
	public function register() {
		add_action( 'admin_init', array( $this, 'handle_save' ) );
	}

	/**
	 * Persist settings.
	 *
	 * @return void
	 */
	public function handle_save() {
		if ( ! isset( $_POST['aksmb_settings_nonce'] ) ) {
			return;
		}
		if ( ! Capabilities::current_user_can_manage() ) {
			return;
		}
		if ( ! wp_verify_nonce( sanitize_text_field( wp_unslash( $_POST['aksmb_settings_nonce'] ) ), 'aksmb_save_settings' ) ) {
			return;
		}

		$critical = isset( $_POST['critical_below'] ) ? sanitize_text_field( wp_unslash( $_POST['critical_below'] ) ) : '0';
		$high     = isset( $_POST['high_below'] ) ? sanitize_text_field( wp_unslash( $_POST['high_below'] ) ) : '3';
		$warning  = isset( $_POST['warning_below'] ) ? sanitize_text_field( wp_unslash( $_POST['warning_below'] ) ) : '10';

		try {
			$profile = new ThresholdProfile(
				ThresholdProfile::percent_to_scaled( $critical ),
				ThresholdProfile::percent_to_scaled( $high ),
				ThresholdProfile::percent_to_scaled( $warning )
			);
		} catch ( \InvalidArgumentException $e ) {
			add_settings_error( 'aksmb', 'thresholds', $e->getMessage(), 'error' );
			return;
		}

		$percent = isset( $_POST['global_assumed_cost_percent'] ) ? sanitize_text_field( wp_unslash( $_POST['global_assumed_cost_percent'] ) ) : '';
		if ( '' !== $percent ) {
			if ( ! preg_match( '/^\d+(\.\d{1,2})?$/', $percent ) ) {
				add_settings_error( 'aksmb', 'percent', __( 'Assumed cost percentage must be a number between 0 and 100.', 'marginbeacon' ), 'error' );
				return;
			}
			$in_range = bccomp( $percent, '0', 6 ) >= 0 && bccomp( $percent, '100', 6 ) <= 0;
			if ( ! $in_range ) {
				add_settings_error( 'aksmb', 'percent', __( 'Assumed cost percentage must be between 0 and 100.', 'marginbeacon' ), 'error' );
				return;
			}
		}

		$assumed_cost_raw = isset( $_POST['global_assumed_cost'] ) ? sanitize_text_field( wp_unslash( $_POST['global_assumed_cost'] ) ) : '';
		if ( '' !== $assumed_cost_raw && ! preg_match( '/^\d+(\.\d+)?$/', $assumed_cost_raw ) ) {
			add_settings_error( 'aksmb', 'cost', __( 'Global assumed cost must be a valid decimal amount.', 'marginbeacon' ), 'error' );
			return;
		}

		$settings = get_option( Constants::OPTION_SETTINGS, array() );
		if ( ! is_array( $settings ) ) {
			$settings = array();
		}
		$prev_thresholds    = isset( $settings['thresholds'] ) && is_array( $settings['thresholds'] )
			? $settings['thresholds']
			: Constants::default_thresholds();
		$new_thresholds     = $profile->to_array();
		$thresholds_changed = wp_json_encode( $prev_thresholds ) !== wp_json_encode( $new_thresholds );

		$settings['thresholds']          = $new_thresholds;
		$settings['disclaimer_accepted'] = ! empty( $_POST['disclaimer_accepted'] );
		update_option( Constants::OPTION_SETTINGS, $settings, true );

		$cost = get_option( Constants::OPTION_COST_SETTINGS, array() );
		if ( ! is_array( $cost ) ) {
			$cost = array();
		}
		$prev_cost = $cost;
		$source    = isset( $_POST['canonical_cost_source'] ) ? sanitize_key( wp_unslash( $_POST['canonical_cost_source'] ) ) : '';
		if ( ! ( new CanonicalCostSource() )->is_valid( $source ) ) {
			$source = ( new CanonicalCostSource() )->get();
		}
		$cost['canonical_cost_source'] = $source;
		$cost['prefer_native_cogs']    = ( CanonicalCostSource::WOOCOMMERCE === $source );
		$cost['fallback_enabled']      = ! empty( $_POST['fallback_enabled'] );
		$cost['global_assumed_cost']   = '' !== $assumed_cost_raw ? $assumed_cost_raw : null;
		if ( '' !== $percent ) {
			$cost['global_assumed_cost_percent'] = $percent;
		} else {
			$cost['global_assumed_cost_percent'] = null;
		}
		$cost['custom_meta_key']       = isset( $_POST['custom_meta_key'] )
			? sanitize_text_field( wp_unslash( $_POST['custom_meta_key'] ) )
			: '';
		$cost['cogs_tax_basis']        = isset( $_POST['cogs_tax_basis'] ) && 'inclusive' === $_POST['cogs_tax_basis']
			? 'inclusive'
			: 'exclusive';
		$cost['needs_cogs_correction'] = ( 'inclusive' === $cost['cogs_tax_basis'] );
		update_option( Constants::OPTION_COST_SETTINGS, $cost, true );
		// Explicit Settings choice marks migration decision complete (no silent switch).
		( new CanonicalCostSource() )->set( $source );

		$cost_changed = wp_json_encode( $prev_cost ) !== wp_json_encode( get_option( Constants::OPTION_COST_SETTINGS, array() ) );

		// PRD 17.6 — uninstall retention choice (default keep).
		$delete_on_uninstall = ! empty( $_POST['uninstall_delete_data'] );
		update_option( Constants::OPTION_UNINSTALL_DELETE_DATA, $delete_on_uninstall ? 1 : 0, true );

		$message = __( 'Settings saved.', 'marginbeacon' );
		if ( $thresholds_changed || $cost_changed ) {
			( new \Kayvandra\MarginBeacon\Application\Freshness\FreshnessService() )->on_global_threshold_change();
			$message = __( 'Settings saved. Related preflight findings were marked stale — re-run preflight to refresh.', 'marginbeacon' );
		}

		add_settings_error( 'aksmb', 'saved', $message, 'updated' );
	}

	/**
	 * Render settings form.
	 *
	 * @return void
	 */
	public function render() {
		if ( ! Capabilities::current_user_can_manage() ) {
			wp_die( esc_html__( 'You do not have permission to access MarginBeacon.', 'marginbeacon' ) );
		}

		settings_errors( 'aksmb' );

		$settings = get_option( Constants::OPTION_SETTINGS, array() );
		$cost     = get_option( Constants::OPTION_COST_SETTINGS, array() );
		$t        = isset( $settings['thresholds'] ) ? $settings['thresholds'] : Constants::default_thresholds();

		$fmt = static function ( $scaled ) {
			return number_format( ( (int) $scaled ) / Constants::THRESHOLD_SCALE, 4, '.', '' );
		};
		?>
		<div class="aksmb-page">
		<p class="aksmb-tagline">
			<?php echo esc_html__( 'Global thresholds and cost resolution for Free.', 'marginbeacon' ); ?>
		</p>

		<form method="post" class="aksmb-settings-form">
			<?php wp_nonce_field( 'aksmb_save_settings', 'aksmb_settings_nonce' ); ?>

			<fieldset class="aksmb-settings-group">
				<legend class="screen-reader-text"><?php echo esc_html__( 'Global threshold profile (%)', 'marginbeacon' ); ?></legend>
				<div class="aksmb-section-header">
					<h2><?php echo esc_html__( 'Global threshold profile (%)', 'marginbeacon' ); ?></h2>
				</div>
				<p class="aksmb-panel__lead"><?php echo esc_html__( 'Thresholds classify the gross product margin on promoted order lines. Critical is the worst financial outcome — lower is riskier.', 'marginbeacon' ); ?></p>
				<table class="form-table">
					<tr>
						<th scope="row"><label for="critical_below"><?php echo esc_html__( 'Critical below', 'marginbeacon' ); ?></label></th>
						<td>
							<input name="critical_below" id="critical_below" type="number" min="0" step="0.01" class="aksmb-threshold-input aksmb-threshold-input--critical" value="<?php echo esc_attr( $fmt( $t['critical_below'] ) ); ?>" />
							<p class="description"><?php echo esc_html__( 'Gross margin below this percent is Critical (worst financial severity).', 'marginbeacon' ); ?></p>
						</td>
					</tr>
					<tr>
						<th scope="row"><label for="high_below"><?php echo esc_html__( 'High below', 'marginbeacon' ); ?></label></th>
						<td>
							<input name="high_below" id="high_below" type="number" min="0" step="0.01" class="aksmb-threshold-input aksmb-threshold-input--high" value="<?php echo esc_attr( $fmt( $t['high_below'] ) ); ?>" />
							<p class="description"><?php echo esc_html__( 'Gross margin at-or-above Critical threshold but below this is High.', 'marginbeacon' ); ?></p>
						</td>
					</tr>
					<tr>
						<th scope="row"><label for="warning_below"><?php echo esc_html__( 'Warning below (Safe starts here)', 'marginbeacon' ); ?></label></th>
						<td>
							<input name="warning_below" id="warning_below" type="number" min="0" step="0.01" class="aksmb-threshold-input aksmb-threshold-input--warning" value="<?php echo esc_attr( $fmt( $t['warning_below'] ) ); ?>" />
							<p class="description"><?php echo esc_html__( 'Gross margin at-or-above this percent is Safe — but never when evidence is missing, stale, or unsupported.', 'marginbeacon' ); ?></p>
						</td>
					</tr>
				</table>
			</fieldset>

			<fieldset class="aksmb-settings-group">
				<legend class="screen-reader-text"><?php echo esc_html__( 'Cost settings', 'marginbeacon' ); ?></legend>
				<div class="aksmb-section-header">
					<h2><?php echo esc_html__( 'Cost settings', 'marginbeacon' ); ?></h2>
				</div>
				<p>
					<a class="button" href="<?php echo esc_url( Tabs::url( Tabs::COST_SETUP ) ); ?>">
						<?php echo esc_html__( 'Open COGS Wizard', 'marginbeacon' ); ?>
					</a>
				</p>
				<table class="form-table">
					<tr>
						<th scope="row"><?php echo esc_html__( 'Canonical cost source', 'marginbeacon' ); ?></th>
						<td>
							<?php
							$current_source = isset( $cost['canonical_cost_source'] )
								? (string) $cost['canonical_cost_source']
								: ( new CanonicalCostSource() )->get();
							?>
							<fieldset>
								<label>
									<input type="radio" name="canonical_cost_source" value="marginbeacon" <?php checked( $current_source, CanonicalCostSource::MARGINBEACON ); ?> />
									<?php echo esc_html__( 'MarginBeacon Cost', 'marginbeacon' ); ?>
								</label><br />
								<label>
									<input type="radio" name="canonical_cost_source" value="woocommerce" <?php checked( $current_source, CanonicalCostSource::WOOCOMMERCE ); ?> />
									<?php echo esc_html__( 'WooCommerce COGS', 'marginbeacon' ); ?>
								</label>
							</fieldset>
							<p class="description">
								<?php echo esc_html__( 'Only one Exact cost source is active. Changing this never deletes the other store’s data.', 'marginbeacon' ); ?>
								<a href="<?php echo esc_url( Tabs::url( Tabs::COST_SETUP, array( 'view' => 'migration' ) ) ); ?>">
									<?php echo esc_html__( 'Open COGS Migration Review', 'marginbeacon' ); ?>
								</a>
							</p>
						</td>
					</tr>
					<tr>
						<th scope="row"><label for="fallback_enabled"><?php echo esc_html__( 'Global assumed-cost fallback', 'marginbeacon' ); ?></label></th>
						<td>
							<label>
								<input type="checkbox" id="fallback_enabled" name="fallback_enabled" value="1" <?php checked( ! empty( $cost['fallback_enabled'] ) ); ?> />
								<?php echo esc_html__( 'Enable fallback', 'marginbeacon' ); ?>
							</label>
							<p class="description"><?php echo esc_html__( 'When Exact MarginBeacon cost is missing, estimate from the rules below (MarginBeacon source only). Estimated results are never Safe on their own.', 'marginbeacon' ); ?></p>
							<fieldset class="aksmb-ack-fieldset aksmb-nested">
								<legend class="screen-reader-text"><?php echo esc_html__( 'Fallback estimation rules', 'marginbeacon' ); ?></legend>
								<p>
									<label for="global_assumed_cost_percent"><?php echo esc_html__( 'Assumed cost as % of regular price', 'marginbeacon' ); ?></label>
									<input id="global_assumed_cost_percent" name="global_assumed_cost_percent" type="number" min="0" max="100" step="0.01" class="small-text"
										value="<?php echo esc_attr( isset( $cost['global_assumed_cost_percent'] ) ? (string) $cost['global_assumed_cost_percent'] : '' ); ?>" />
								</p>
								<p>
									<label for="global_assumed_cost"><?php echo esc_html__( 'Or absolute assumed cost (legacy)', 'marginbeacon' ); ?></label>
									<input id="global_assumed_cost" name="global_assumed_cost" type="text" value="<?php echo esc_attr( isset( $cost['global_assumed_cost'] ) ? (string) $cost['global_assumed_cost'] : '' ); ?>" class="regular-text" placeholder="0.00" />
								</p>
								<p class="description"><?php echo esc_html__( 'Category assumed-cost rules are Pro-only.', 'marginbeacon' ); ?></p>
							</fieldset>
						</td>
					</tr>
					<tr>
						<th scope="row"><label for="custom_meta_key"><?php echo esc_html__( 'Custom meta key', 'marginbeacon' ); ?></label></th>
						<td>
							<input id="custom_meta_key" name="custom_meta_key" type="text" class="regular-text"
								value="<?php echo esc_attr( isset( $cost['custom_meta_key'] ) ? (string) $cost['custom_meta_key'] : '' ); ?>"
								placeholder="_my_cost_meta" />
							<p class="description"><?php echo esc_html__( 'Read a numeric tax-exclusive cost from this meta key when MarginBeacon manual cost is empty (MarginBeacon source only).', 'marginbeacon' ); ?></p>
						</td>
					</tr>
					<tr>
						<th scope="row"><label for="cogs_tax_basis"><?php echo esc_html__( 'COGS tax basis', 'marginbeacon' ); ?></label></th>
						<td>
							<select id="cogs_tax_basis" name="cogs_tax_basis">
								<option value="exclusive" <?php selected( empty( $cost['cogs_tax_basis'] ) || 'exclusive' === $cost['cogs_tax_basis'] ); ?>><?php echo esc_html__( 'Tax-exclusive (required)', 'marginbeacon' ); ?></option>
								<option value="inclusive" <?php selected( isset( $cost['cogs_tax_basis'] ) && 'inclusive' === $cost['cogs_tax_basis'] ); ?>><?php echo esc_html__( 'Tax-inclusive (blocks Safe)', 'marginbeacon' ); ?></option>
							</select>
							<p class="description"><?php echo esc_html__( 'Tax-exclusive costs are required for a Safe result. Tax-inclusive costs block Safe (MB_COGS_TAX_BASIS_INVALID).', 'marginbeacon' ); ?></p>
						</td>
					</tr>
				</table>
			</fieldset>

			<fieldset class="aksmb-settings-group">
				<legend class="screen-reader-text"><?php echo esc_html__( 'Uninstall data retention', 'marginbeacon' ); ?></legend>
				<div class="aksmb-section-header">
					<h2><?php echo esc_html__( 'Uninstall data retention', 'marginbeacon' ); ?></h2>
				</div>
				<p class="aksmb-panel__lead"><?php echo esc_html__( 'When you delete the MarginBeacon plugin from WordPress, choose whether stored risk data is removed. Deactivation alone never deletes data.', 'marginbeacon' ); ?></p>
				<table class="form-table">
					<tr>
						<th scope="row"><?php echo esc_html__( 'On plugin delete', 'marginbeacon' ); ?></th>
						<td>
							<?php $delete_data = (bool) get_option( Constants::OPTION_UNINSTALL_DELETE_DATA, false ); ?>
							<fieldset class="aksmb-ack-fieldset aksmb-nested">
								<legend class="screen-reader-text"><?php echo esc_html__( 'Data retention on uninstall', 'marginbeacon' ); ?></legend>
								<p><label><input type="radio" name="uninstall_delete_data" value="0" <?php checked( ! $delete_data ); ?> /> <?php echo esc_html__( 'Keep MarginBeacon data (recommended)', 'marginbeacon' ); ?></label></p>
								<p><label><input type="radio" name="uninstall_delete_data" value="1" <?php checked( $delete_data ); ?> /> <?php echo esc_html__( 'Delete all MarginBeacon tables and settings on uninstall', 'marginbeacon' ); ?></label></p>
								<?php if ( $delete_data ) : ?>
									<p class="description aksmb-field-error"><?php echo esc_html__( 'Warning: uninstall will permanently drop order-risk snapshots, findings, price revisions, and settings.', 'marginbeacon' ); ?></p>
								<?php endif; ?>
							</fieldset>
						</td>
					</tr>
				</table>
			</fieldset>

			<p>
				<label>
					<input type="checkbox" name="disclaimer_accepted" value="1" <?php checked( ! empty( $settings['disclaimer_accepted'] ) ); ?> />
					<?php echo esc_html__( 'I understand MarginBeacon reports gross product margin estimates only, not financial advice.', 'marginbeacon' ); ?>
				</label>
			</p>

			<?php submit_button( __( 'Save settings', 'marginbeacon' ) ); ?>
		</form>
		<?php
		/**
		 * Pro companion panels on Settings (category thresholds, etc.).
		 */
		do_action( 'aksmb_settings_pro_panel' );
		?>
		</div>
		<?php
	}
}