<?php

if (!defined('ABSPATH')) {
    exit;
}

/**
 * Plugin settings with safe defaults. Everything works without the user
 * touching this: daily full backup at 03:00, keep the last 5 on this server.
 */
final class SWPB_Settings
{
    public const OPTION = 'swpb_settings';

    public const TYPES = ['full', 'database', 'files'];
    public const SCHEDULES = ['off', 'daily', 'weekly', 'monthly'];
    public const SCOPES = ['content', 'full'];
    public const NOTIFY = ['never', 'failure', 'always'];
    /** Low-impact mode: seconds to pause between backup steps (0 = off). */
    public const STEP_PAUSES = [0, 5, 15, 30];

    public function defaults(): array
    {
        return [
            'setup_done' => false,
            'schedule' => 'daily',
            'schedule_time' => '03:00',
            'schedule_weekday' => 1,
            'schedule_monthday' => 1,
            'schedule_type' => 'full',
            'file_scope' => 'content',
            'exclude_default' => true,
            'exclude_vcs' => true,
            'exclude_custom' => '',
            'max_file_mb' => 0,
            'db_all_tables' => false,
            'exclude_tables' => '',
            'keep_local' => 5,
            'notify_on' => 'failure',
            'notify_email' => '',
            'time_budget' => 20,
            'step_pause' => 0,
            'part_size_mb' => 0,
        ];
    }

    public function all(): array
    {
        $stored = get_option(self::OPTION, []);
        return array_merge($this->defaults(), is_array($stored) ? $stored : []);
    }

    /**
     * @return mixed
     */
    public function get(string $key)
    {
        $all = $this->all();
        return $all[$key] ?? null;
    }

    /**
     * Merge and sanitize a (partial) set of values. Keys not present in $input keep their value.
     */
    public function save(array $input): array
    {
        $current = $this->all();
        $out = $current;

        if (array_key_exists('setup_done', $input)) {
            $out['setup_done'] = !empty($input['setup_done']);
        }
        if (isset($input['schedule'])) {
            $out['schedule'] = $this->pick((string)$input['schedule'], self::SCHEDULES, 'daily');
        }
        if (isset($input['schedule_time'])) {
            $time = (string)$input['schedule_time'];
            $out['schedule_time'] = preg_match('/^([01]\d|2[0-3]):[0-5]\d$/', $time) ? $time : '03:00';
        }
        if (isset($input['schedule_weekday'])) {
            $out['schedule_weekday'] = $this->clamp((int)$input['schedule_weekday'], 0, 6);
        }
        if (isset($input['schedule_monthday'])) {
            $out['schedule_monthday'] = $this->clamp((int)$input['schedule_monthday'], 1, 28);
        }
        if (isset($input['schedule_type'])) {
            $out['schedule_type'] = $this->pick((string)$input['schedule_type'], self::TYPES, 'full');
        }
        if (isset($input['file_scope'])) {
            $out['file_scope'] = $this->pick((string)$input['file_scope'], self::SCOPES, 'content');
        }
        foreach (['exclude_default', 'exclude_vcs', 'db_all_tables'] as $flag) {
            if (array_key_exists($flag, $input)) {
                $out[$flag] = !empty($input[$flag]);
            }
        }
        if (isset($input['exclude_custom'])) {
            $out['exclude_custom'] = $this->clean_lines((string)$input['exclude_custom']);
        }
        if (isset($input['exclude_tables'])) {
            $out['exclude_tables'] = $this->clean_lines((string)$input['exclude_tables']);
        }
        if (isset($input['max_file_mb'])) {
            $out['max_file_mb'] = $this->clamp((int)$input['max_file_mb'], 0, 100000);
        }
        if (isset($input['keep_local'])) {
            $out['keep_local'] = $this->clamp((int)$input['keep_local'], 0, 100);
        }
        if (isset($input['notify_on'])) {
            $out['notify_on'] = $this->pick((string)$input['notify_on'], self::NOTIFY, 'failure');
        }
        if (isset($input['notify_email'])) {
            $emails = [];
            foreach (preg_split('/[\s,;]+/', (string)$input['notify_email']) as $email) {
                $email = sanitize_email($email);
                if ($email !== '' && is_email($email)) {
                    $emails[] = $email;
                }
            }
            $out['notify_email'] = implode(', ', array_unique($emails));
        }
        if (isset($input['time_budget'])) {
            $out['time_budget'] = $this->clamp((int)$input['time_budget'], 5, 120);
        }
        if (isset($input['step_pause'])) {
            $pause = (int)$input['step_pause'];
            $out['step_pause'] = in_array($pause, self::STEP_PAUSES, true) ? $pause : 0;
        }
        if (isset($input['part_size_mb'])) {
            $part = (int)$input['part_size_mb'];
            $out['part_size_mb'] = $part <= 0 ? 0 : $this->clamp($part, 50, 100000);
        }

        update_option(self::OPTION, $out, false);
        return $out;
    }

    /**
     * Recipients for notifications; falls back to the site admin email.
     */
    public function notify_recipients(): array
    {
        $raw = trim((string)$this->get('notify_email'));
        if ($raw === '') {
            return [(string)get_option('admin_email')];
        }
        return array_filter(array_map('trim', explode(',', $raw)));
    }

    public function lines(string $key): array
    {
        return array_values(array_filter(array_map('trim', explode("\n", (string)$this->get($key)))));
    }

    private function pick(string $value, array $allowed, string $fallback): string
    {
        return in_array($value, $allowed, true) ? $value : $fallback;
    }

    private function clamp(int $value, int $min, int $max): int
    {
        return max($min, min($max, $value));
    }

    private function clean_lines(string $raw): string
    {
        $lines = [];
        foreach (preg_split('/\r\n|\r|\n/', $raw) as $line) {
            $line = trim(sanitize_text_field($line));
            if ($line !== '') {
                $lines[] = $line;
            }
        }
        return implode("\n", array_unique($lines));
    }
}