<?php

namespace App\Support;

use App\Models\Application;
use App\Models\AudienceRegistration;
use App\Models\Competition;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Http\Request;

final class SignupSchemaLayout
{
    /** @var list<string> */
    private const SKIP_KEYS = ['commitment_accepted', 'plan', 'supporting', 'promise_signature'];

    /** @var list<string> */
    private const SKIP_TYPES = ['file'];

    /** @var list<string> */
    private const AUDIENCE_COLUMNS = ['name', 'phone', 'company', 'job', 'purpose'];

    /**
     * @param  list<mixed>|null  $schemaJson
     * @return list<array{key: string, type: string, label: string, list: bool, filter: bool, options: list<array{value: string, label: string}>}>
     */
    public static function fields(?array $schemaJson): array
    {
        if (! is_array($schemaJson)) {
            return [];
        }
        $out = [];
        foreach ($schemaJson as $row) {
            if (! is_array($row)) {
                continue;
            }
            $key = trim((string) ($row['key'] ?? ''));
            $type = trim((string) ($row['type'] ?? ''));
            if ($key === '' || in_array($key, self::SKIP_KEYS, true) || in_array($type, self::SKIP_TYPES, true)) {
                continue;
            }
            $label = trim((string) ($row['label'] ?? $key));
            $options = [];
            if (($row['options'] ?? null) && is_array($row['options'])) {
                foreach ($row['options'] as $opt) {
                    if (! is_array($opt)) {
                        continue;
                    }
                    $value = trim((string) ($opt['value'] ?? ''));
                    if ($value === '') {
                        continue;
                    }
                    $options[] = [
                        'value' => $value,
                        'label' => trim((string) ($opt['label'] ?? $value)),
                    ];
                }
            }
            $out[] = [
                'key' => $key,
                'type' => $type !== '' ? $type : 'text',
                'label' => $label !== '' ? $label : $key,
                'list' => ($row['list'] ?? false) === true,
                'filter' => ($row['filter'] ?? false) === true,
                'options' => $options,
            ];
        }

        return $out;
    }

    /**
     * @param  list<mixed>|null  $schemaJson
     * @return list<array{key: string, type: string, label: string, list: bool, filter: bool, options: list<array{value: string, label: string}>}>
     */
    public static function listFields(?array $schemaJson): array
    {
        return array_values(array_filter(self::fields($schemaJson), fn (array $f) => $f['list']));
    }

    /**
     * @param  list<mixed>|null  $schemaJson
     * @return list<array{key: string, type: string, label: string, list: bool, filter: bool, options: list<array{value: string, label: string}>}>
     */
    public static function filterFields(?array $schemaJson): array
    {
        return array_values(array_filter(
            self::fields($schemaJson),
            fn (array $f) => $f['filter'] && ($f['type'] === 'select' || in_array($f['key'], ['track', 'purpose'], true))
        ));
    }

    /**
     * 管理端筛选项（中文标签）；赛道/场次补全选项。
     *
     * @return list<array{key: string, type: string, label: string, options: list<array{value: string, label: string}>}>
     */
    public static function adminFilterFields(Competition $competition, string $purpose = 'signup'): array
    {
        $schema = $purpose === 'audience'
            ? ($competition->audienceFormSchema?->schema_json)
            : ($competition->formSchema?->schema_json);
        $fields = self::filterFields(is_array($schema) ? $schema : null);
        $out = [];
        foreach ($fields as $field) {
            $options = $field['options'];
            if ($field['key'] === 'track') {
                if ($options === []) {
                    $competition->loadMissing('tracks');
                    foreach ($competition->tracks as $track) {
                        $options[] = [
                            'value' => (string) $track->track_code,
                            'label' => (string) $track->title,
                        ];
                    }
                }
                $hasOther = false;
                foreach ($options as $opt) {
                    if (($opt['value'] ?? '') === SignupDisplay::TRACK_OTHER_CODE) {
                        $hasOther = true;
                        break;
                    }
                }
                if (! $hasOther) {
                    $options[] = [
                        'value' => SignupDisplay::TRACK_OTHER_CODE,
                        'label' => '其他',
                    ];
                }
            }
            if ($purpose === 'audience' && $field['key'] === 'audience_session_id' && $options === []) {
                $competition->loadMissing('audienceSessions');
                foreach ($competition->audienceSessions as $session) {
                    $options[] = [
                        'value' => (string) $session->id,
                        'label' => (string) $session->name,
                    ];
                }
            }
            $out[] = [
                'key' => $field['key'],
                'type' => $field['type'],
                'label' => $field['label'],
                'options' => $options,
            ];
        }

        return $out;
    }

    /**
     * @return list<array{key: string, type: string, label: string}>
     */
    public static function adminListFields(Competition $competition, string $purpose = 'signup'): array
    {
        $schema = $purpose === 'audience'
            ? ($competition->audienceFormSchema?->schema_json)
            : ($competition->formSchema?->schema_json);
        $out = [];
        foreach (self::listFields(is_array($schema) ? $schema : null) as $field) {
            $out[] = [
                'key' => $field['key'],
                'type' => $field['type'],
                'label' => $field['label'],
            ];
        }

        return $out;
    }

    /**
     * @param  array<string, mixed>  $filters
     */
    public static function extractFilterValues(Request $request, Competition $competition, string $purpose = 'signup'): array
    {
        $out = [];
        foreach (self::adminFilterFields($competition, $purpose) as $field) {
            $key = $field['key'];
            if (! $request->exists($key)) {
                continue;
            }
            $value = trim((string) $request->input($key));
            if ($value !== '') {
                $out[$key] = $value;
            }
        }

        return $out;
    }

    /**
     * @param  Builder<\App\Models\Application|\App\Models\AudienceRegistration>  $query
     * @param  array<string, mixed>  $filters
     * @param  list<string>  $alreadyApplied
     */
    public static function applyFilters(
        Builder $query,
        Competition $competition,
        array $filters,
        string $purpose = 'signup',
        array $alreadyApplied = ['track', 'event_location', 'purpose'],
    ): void {
        $schema = $purpose === 'audience'
            ? ($competition->audienceFormSchema?->schema_json)
            : ($competition->formSchema?->schema_json);
        $columnKeys = $purpose === 'audience'
            ? array_flip(self::AUDIENCE_COLUMNS)
            : array_flip(SignupApplicationFieldRegistry::scalarColumnKeys());
        $skip = array_flip($alreadyApplied);

        foreach (self::filterFields(is_array($schema) ? $schema : null) as $field) {
            $key = $field['key'];
            if (isset($skip[$key])) {
                continue;
            }
            $value = trim((string) ($filters[$key] ?? ''));
            if ($value === '') {
                continue;
            }
            if ($purpose === 'signup' && in_array($key, ['degree', 'location_country', 'event_location'], true)) {
                $value = SignupOptionCatalog::normalize($key, $value) ?: $value;
            }
            if ($purpose === 'audience' && $key === 'purpose') {
                $value = SignupOptionCatalog::normalize('purpose', $value) ?: $value;
            }
            if (isset($columnKeys[$key])) {
                $query->where($key, $value);
            } else {
                $query->where('answers_json->'.$key, $value);
            }
        }
    }

    /**
     * @return array<string, string>
     */
    public static function applicationDisplayMap(Competition $competition, Application $app): array
    {
        $competition->loadMissing('formSchema');
        $schema = $competition->formSchema?->schema_json;
        $schemaArr = is_array($schema) ? $schema : null;
        $out = [];
        foreach (self::listFields($schemaArr) as $field) {
            $out[$field['key']] = SignupDisplay::applicationFieldLabel($competition, $app, $field['key'], $schemaArr);
        }

        return $out;
    }

    /**
     * @return array<string, string>
     */
    public static function audienceDisplayMap(Competition $competition, AudienceRegistration $row): array
    {
        $competition->loadMissing('audienceFormSchema');
        $schema = $competition->audienceFormSchema?->schema_json;
        $schemaArr = is_array($schema) ? $schema : null;
        $locale = SignupDisplay::audienceLocale((int) $row->user_id, (int) $row->competition_id);
        $out = [];
        foreach (self::listFields($schemaArr) as $field) {
            $key = $field['key'];
            $raw = SignupDisplay::audienceFieldValue($row, $key);
            $value = is_scalar($raw) ? trim((string) $raw) : '';
            if ($value === '') {
                $out[$key] = '';
                continue;
            }
            if ($key === 'purpose') {
                $out[$key] = SignupDisplay::purposeLabel($value, $locale);
                continue;
            }
            $fieldDef = LocalizedSchema::fieldByKey($schemaArr, $key);
            if ($fieldDef !== null && ($fieldDef['type'] ?? '') === 'select') {
                $out[$key] = LocalizedSchema::optionLabelForValue($fieldDef, $value, $locale);
                continue;
            }
            $out[$key] = $value;
        }

        return $out;
    }
}