<?php

namespace App\Services;

use App\Models\Opportunity;
use App\Support\IsolatedQaDatabase;
use Carbon\CarbonImmutable;
use Illuminate\Http\Request;
use Illuminate\Pagination\LengthAwarePaginator;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Validator;
use Illuminate\Validation\Rule;
use Illuminate\Validation\ValidationException;

/** Read-only consumer. Effective publication remains unavailable until confidentiality is delivered.
 * The injected fixture mode is never configurable by HTTP, environment flags or stored content. */
final class OfferPublicCatalogue
{
    public const CONTRACT = 'offer-public-projection-v1';

    public function __construct(private bool $syntheticFixtureMode = false) {}

    private function fixtureReadAllowed(): bool
    {
        return $this->syntheticFixtureMode && IsolatedQaDatabase::allowsSchemaChanges();
    }

    /** Exact ordering of decimal strings, without currency conversion or floating point.
     * @param string $a @param string $b */
    public static function comparePrice(string $a, string $b): int
    {
        $parts = static function (string $value): array {
            [$whole, $fraction] = [...explode('.', $value), ''];

            return [ltrim($whole, '0') ?: '0', str_pad($fraction, 2, '0')];
        };
        [$aw, $af] = $parts($a);
        [$bw, $bf] = $parts($b);

        return (strlen($aw) <=> strlen($bw)) ?: (strcmp($aw, $bw) <=> 0) ?: (strcmp($af, $bf) <=> 0);
    }

    /** @return array<string,mixed> */
    public function filters(Request $request): array
    {
        $filters = array_intersect_key(app(InvestmentCatalogue::class)->filters($request, true), array_flip([
            'q', 'category', 'province_id', 'district_id', 'currency', 'min_amount', 'max_amount', 'sort', 'view', 'page', 'per_page',
        ]));
        $extra = $request->validate(['price_mode' => 'nullable|in:amount,negotiable']);
        $filters = [...$filters, ...$extra];
        if (isset($filters['min_amount'], $filters['max_amount']) && self::comparePrice($filters['min_amount'], $filters['max_amount']) > 0) {
            throw ValidationException::withMessages(['max_amount' => 'O preço máximo deve ser igual ou superior ao mínimo.']);
        }
        if (in_array($filters['sort'] ?? '', ['amount_asc', 'amount_desc'], true) && empty($filters['currency'])) {
            throw ValidationException::withMessages(['currency' => 'Seleccione uma moeda para ordenar por preço.']);
        }
        if (($filters['price_mode'] ?? '') === 'negotiable' && (isset($filters['min_amount']) || isset($filters['max_amount']))) {
            throw ValidationException::withMessages(['price_mode' => 'Retire o intervalo de montantes para procurar preços a negociar.']);
        }
        if (($filters['price_mode'] ?? '') === 'negotiable' && ! empty($filters['currency'])) {
            throw ValidationException::withMessages(['currency' => 'A moeda de um preço a negociar não foi indicada. Retire este filtro.']);
        }

        return $filters;
    }

    /** The explicit public snapshot, never a projection of current private columns.
     * @return array<string,mixed>|null */
    private function project(int $id, mixed $publication): ?array
    {
        if (! is_array($publication) || ($publication['contract'] ?? null) !== self::CONTRACT || ($publication['qa_fixture'] ?? false) !== true) {
            return null;
        }
        $v = Validator::make($publication, [
            'payload' => 'required|array:title,summary,category,province_id,district_id,price_mode,amount,currency',
            'payload.title' => 'required|string|max:150', 'payload.summary' => 'required|string|max:1500',
            'payload.category' => ['required', Rule::in(OpportunityManagement::CATEGORIES)],
            'payload.province_id' => 'nullable|uuid', 'payload.district_id' => 'nullable|uuid',
            'payload.price_mode' => 'required|in:amount,negotiable',
            'payload.amount' => ['nullable', 'string', 'required_if:payload.price_mode,amount', 'prohibited_unless:payload.price_mode,amount', 'regex:/^\d{1,16}(\.\d{1,2})?$/'],
            'payload.currency' => 'nullable|required_if:payload.price_mode,amount|prohibited_unless:payload.price_mode,amount|in:MZN,USD',
            'approval.state' => 'required|in:approved', 'approval.hash' => 'required|string|size:64', 'approval.actor_id' => 'required|integer|min:1',
            'approval.at' => 'required|date', 'publication.state' => 'required|in:published', 'publication.hash' => 'required|string|size:64',
            'publication.actor_id' => 'required|integer|min:1|different:approval.actor_id', 'publication.at' => 'required|date|after_or_equal:approval.at|before_or_equal:now',
            'revision' => 'required|integer|min:1',
        ]);
        if ($v->fails()) {
            return null;
        }
        $p = $v->validated()['payload'];
        $hash = self::projectionHash($p);
        if (! hash_equals($hash, $publication['approval']['hash']) || ! hash_equals($hash, $publication['publication']['hash'])) {
            return null;
        }
        try {
            $path = app(InvestmentGeography::class)->selection(['province_id' => $p['province_id'] ?? null, 'district_id' => $p['district_id'] ?? null]);
        } catch (ValidationException $error) {
            return null;
        }

        return ['id' => $id, 'title' => $p['title'], 'summary' => $p['summary'], 'category' => $p['category'],
            'location' => array_map(fn ($node) => ['id' => $node->id, 'name' => $node->name, 'level' => $node->location_type], $path),
            'price' => ['mode' => $p['price_mode'], 'amount' => $p['amount'] ?? null, 'currency' => $p['currency'] ?? null],
            'status' => 'published', 'published_at' => CarbonImmutable::parse($publication['publication']['at'])->utc()->toIso8601String(), 'revision' => $publication['revision'], 'url' => '/ofertas/'.$id];
    }

    /** @param array<string,mixed> $payload */
    public static function projectionHash(array $payload): string
    {
        ksort($payload);

        return hash('sha256', json_encode(['contract' => self::CONTRACT, 'payload' => $payload], JSON_THROW_ON_ERROR));
    }

    /** @param array<string,mixed> $filters
     * @return array{records:list<array<string,mixed>>,truncated:bool} */
    public function records(array $filters = []): array
    {
        if (! $this->fixtureReadAllowed()) {
            return ['records' => [], 'truncated' => false];
        }
        $rows = Opportunity::query()->whereNotNull('workflow_context->private_offer_preparation')->whereNotNull('workflow_context->offer_publication')
            ->orderBy('id')->limit(1001)->get(['id', DB::raw("workflow_context->'offer_publication' AS public_snapshot"), DB::raw("workflow_context->'offer_operation' AS operation_state")]);
        $records = [];
        foreach ($rows->take(1000) as $row) {
            if (! is_string($row->getAttribute('public_snapshot'))) {
                continue;
            }
            try {
                $publication = json_decode($row->getAttribute('public_snapshot'), true, 512, JSON_THROW_ON_ERROR);
                $operation = json_decode($row->getAttribute('operation_state') ?? 'null', true, 512, JSON_THROW_ON_ERROR);
            } catch (\JsonException $error) {
                continue;
            }
            if (! app(OfferAvailability::class)->publicAllowed($operation, $publication)) {
                continue;
            }
            $p = $this->project($row->id, $publication);
            if (! $p) {
                continue;
            }
            $expires = app(OfferAvailability::class)->view($operation, $publication)['expires_at'];
            if ($expires !== null) {
                $p['expires_at'] = $expires;
            }
            if (! empty($filters['q']) && ! str_contains(mb_strtolower($p['title'].' '.$p['summary']), mb_strtolower($filters['q']))) {
                continue;
            }
            if (! empty($filters['category']) && $p['category'] !== $filters['category']) {
                continue;
            }
            if (! empty($filters['province_id']) && ($p['location'][0]['id'] ?? null) !== $filters['province_id']) {
                continue;
            }
            if (! empty($filters['district_id']) && ($p['location'][1]['id'] ?? null) !== $filters['district_id']) {
                continue;
            }
            if (! empty($filters['price_mode']) && $p['price']['mode'] !== $filters['price_mode']) {
                continue;
            }
            if (! empty($filters['currency']) && $p['price']['currency'] !== $filters['currency']) {
                continue;
            }
            if (isset($filters['min_amount']) && ($p['price']['amount'] === null || self::comparePrice($p['price']['amount'], $filters['min_amount']) < 0)) {
                continue;
            }
            if (isset($filters['max_amount']) && ($p['price']['amount'] === null || self::comparePrice($p['price']['amount'], $filters['max_amount']) > 0)) {
                continue;
            }
            $records[] = $p;
        }
        $sort = $filters['sort'] ?? 'recent';
        usort($records, static function ($a, $b) use ($sort): int {
            if ($sort === 'title') {
                return strnatcasecmp($a['title'], $b['title']) ?: ($a['id'] <=> $b['id']);
            }
            if (in_array($sort, ['amount_asc', 'amount_desc'], true)) {
                if ($a['price']['amount'] === null || $b['price']['amount'] === null) {
                    return ($a['price']['amount'] === null) <=> ($b['price']['amount'] === null);
                }

                return self::comparePrice($a['price']['amount'], $b['price']['amount']) * ($sort === 'amount_desc' ? -1 : 1) ?: ($a['id'] <=> $b['id']);
            }

            return strcmp($b['published_at'], $a['published_at']) ?: ($b['id'] <=> $a['id']);
        });

        return ['records' => $records, 'truncated' => $rows->count() > 1000];
    }

    /** @return array<string,mixed> */
    public function detail(int $id): array
    {
        abort_unless($this->fixtureReadAllowed(), 404);
        $row = Opportunity::query()->whereKey($id)->whereNotNull('workflow_context->private_offer_preparation')->first(['id', DB::raw("workflow_context->'offer_publication' AS public_snapshot"), DB::raw("workflow_context->'offer_operation' AS operation_state")]);
        if (! $row || ! is_string($row->getAttribute('public_snapshot'))) {
            abort(404);
        }
        try {
            $publication = json_decode($row->getAttribute('public_snapshot'), true, 512, JSON_THROW_ON_ERROR);
            $operation = json_decode($row->getAttribute('operation_state') ?? 'null', true, 512, JSON_THROW_ON_ERROR);
        } catch (\JsonException $error) {
            abort(404);
        }
        abort_unless(app(OfferAvailability::class)->publicAllowed($operation, $publication), 404);
        $record = $this->project($id, $publication);
        abort_unless($record !== null, 404);
        $expires = app(OfferAvailability::class)->view($operation, $publication)['expires_at'];
        if ($expires !== null) {
            $record['expires_at'] = $expires;
        }

        return $record;
    }

    /** @param array<string,mixed> $filters
     * @return array{results:LengthAwarePaginator<int,array<string,mixed>>,truncated:bool} */
    public function page(Request $request, array $filters): array
    {
        $result = $this->records($filters);
        $size = (int) ($filters['per_page'] ?? 12);
        $page = (int) ($filters['page'] ?? 1);

        return ['results' => new LengthAwarePaginator(array_slice($result['records'], ($page - 1) * $size, $size), count($result['records']), $size, $page,
            ['path' => $request->url(), 'query' => $filters]), 'truncated' => $result['truncated']];
    }

    /** @param array<string,mixed> $filters
     * @return array<string,mixed> */
    public function map(array $filters): array
    {
        $result = $this->records($filters);
        $areas = [];
        $seen = [];
        foreach ($result['records'] as $record) {
            $id = $record['location'][array_key_last($record['location'])]['id'] ?? null;
            if (! $id || isset($seen[$id])) {
                continue;
            }
            $seen[$id] = true;
            $areas = [...$areas, ...app(TerritoryGeometry::class)->context($id)['areas']];
            if (count($seen) >= 30) {
                break;
            }
        }

        return ['features' => [], 'areas' => $areas, 'matched_count' => count($result['records']), 'exact_locations_disclosed' => false,
            'truncated' => $result['truncated'] || count($seen) >= 30];
    }
}