<?php

namespace App\Services;

use App\Models\ExistingBusiness;
use App\Models\Opportunity;
use App\Models\Sector;
use App\Models\User;
use Illuminate\Database\Eloquent\ModelNotFoundException;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;
use Illuminate\Support\Facades\Validator;
use Illuminate\Support\Str;
use Symfony\Component\HttpKernel\Exception\HttpException;

/** Context belongs to the existing encrypted dossier. Sources remain read-only. */
final class InvestorContext
{
    public const MIGRATION = '2026_10_16_150000_create_investor_navigation_preferences';

    public const SOURCE = 'investor-context';

    public const FIELDS = ['project_title', 'project_summary', 'sector_id', 'sector', 'province_id', 'district_id', 'admin_post_id', 'locality_id', 'province', 'district', 'location'];

    public function __construct(private readonly VirtualDesk $desk) {}

    public function installed(): bool
    {
        return Schema::hasTable('investor_navigation_preferences');
    }

    public function state(\stdClass $case): array
    {
        $payload = $this->desk->decode($case->payload);

        return $payload['investor_path']['context'] ?? ['revision' => 0, 'selection' => [],
            'fields' => ['project_title' => $case->title], 'provenance' => ['project_title' => ['kind' => 'dossier', 'id' => $case->id, 'version' => $case->version]], 'review_steps' => []];
    }

    public function dependencyHash(array $selection): string
    {
        return hash('sha256', json_encode(Arr::sortRecursive($selection), JSON_THROW_ON_ERROR));
    }

    public function reference(string $key): array
    {
        [$kind,$id] = array_pad(explode(':', $key, 2), 2, '');
        $fields = [];
        $href = '';
        $title = '';
        $version = null;
        if ($kind === 'opportunity') {
            abort_unless(ctype_digit($id), 422, 'Identificador de oportunidade inválido.');
            $o = Opportunity::published()->with('sector')->findOrFail((int) $id);
            $title = $o->title;
            $href = '/oportunidades/'.$o->slug;
            $version = $o->management_version;
            $fields = ['project_title' => $o->title, 'project_summary' => $o->summary];
            if ($o->sector) {
                $fields['sector_id'] = (string) $o->sector_id;
                $fields['sector'] = $o->sector->name;
            }
            // Text labels do not establish a canonical territorial correspondence.
            if ($o->province) {
                $fields['province'] = $o->province;
            }
            if ($o->district) {
                $fields['district'] = $o->district;
            }
            if ($o->primary_territory_id) {
                $fields = [...$fields, ...$this->territoryFields($o->primary_territory_id)];
            }
        } elseif ($kind === 'business') {
            abort_unless(config('existing-business.enabled') && Str::isUuid($id), 404);
            $o = ExistingBusiness::published()->with('sector')->findOrFail($id);
            $title = $o->public_title;
            $href = '/negocios/'.$o->public_slug;
            $version = $o->version_no;
            $fields = ['project_title' => $o->public_title, 'project_summary' => $o->objective];
            if ($o->sector) {
                $fields['sector_id'] = (string) $o->sector_id;
                $fields['sector'] = $o->sector->name;
            }
            $location = DB::table('existing_business_locations')->where('existing_business_id', $id)->where('is_public', true)->where('is_primary', true)->first();
            if ($location) {
                $leaf = $location->province_id;
                foreach (['district', 'admin_post', 'locality'] as $level) {
                    if (in_array($location->precision_level, array_slice(['province', 'district', 'admin_post', 'locality', 'exact'], array_search($level, ['province', 'district', 'admin_post', 'locality', 'exact'])), true) && $location->{$level.'_id'}) {
                        $leaf = $location->{$level.'_id'};
                    }
                }
                if ($leaf) {
                    $fields = [...$fields, ...$this->territoryFields($leaf)];
                }
            }
        } elseif ($kind === 'sector') {
            abort_unless(ctype_digit($id), 422);
            $s = Sector::where('is_active', true)->findOrFail((int) $id);
            $title = $s->name;
            $href = SectorOrganization::href($s->slug);
            $version = $s->updated_at?->toIso8601String();
            $fields = ['sector_id' => (string) $s->id, 'sector' => $s->name];
        } elseif ($kind === 'territory') {
            abort_unless(Str::isUuid($id), 422);
            $t = app(InvestmentGeography::class)->publicReferences()->whereIn('location_type', array_values(InvestmentGeography::FIELDS))->where('id', $id)->first();
            abort_unless($t, 404, 'Território público indisponível.');
            $title = $t->name;
            $version = $t->version_no;
            $href = '/oportunidades?'.$t->location_type.'_id='.$id;
            $fields = $this->territoryFields($id);
        } elseif ($kind === 'park') {
            abort_unless(Str::isUuid($id), 422);
            $p = app(InvestmentZones::class)->visible()->where('category', 'industrial_park')->findOrFail($id);
            $title = $p->name;
            $version = $p->version_no;
            $href = '/zonas/'.$id;
            if ($p->primary_territory_id) {
                $fields = $this->territoryFields($p->primary_territory_id);
            }
        } else {
            abort(422, 'Tipo de referência inválido.');
        }
        $fields = array_filter($fields, fn ($v) => is_scalar($v) && trim((string) $v) !== '');
        $record = ['key' => $key, 'kind' => $kind, 'id' => $id, 'title' => $title, 'version' => $version, 'href' => $href, 'fields' => $fields];

        return [...$record, 'sha256' => hash('sha256', json_encode($record, JSON_THROW_ON_ERROR))];
    }

    private function territoryFields(string $id): array
    {
        $path = app(InvestmentGeography::class)->path($id);
        $fields = [];
        $names = [];
        foreach ($path as $n) {
            if (! in_array($n->location_type, array_values(InvestmentGeography::FIELDS), true)) {
                continue;
            }
            $fields[$n->location_type.'_id'] = $n->id;
            $names[] = $n->name;
            if (in_array($n->location_type, ['province', 'district'], true)) {
                $fields[$n->location_type] = $n->name;
            }
        }
        if ($names) {
            $fields['location'] = implode(' / ', $names);
        }

        return $fields;
    }

    public function options(string $query = ''): array
    {
        $query = mb_substr(trim($query), 0, 120);
        $items = [];
        foreach (Opportunity::published()->when($query, fn ($q) => $q->where('title', 'ilike', '%'.$query.'%'))->orderBy('title')->limit(51)->get(['id', 'title']) as $o) {
            $items[] = ['key' => 'opportunity:'.$o->id, 'title' => $o->title, 'kind' => 'opportunity'];
        }
        if (config('existing-business.enabled')) {
            foreach (ExistingBusiness::published()->when($query, fn ($q) => $q->where('public_title', 'ilike', '%'.$query.'%'))->orderBy('public_title')->limit(51)->get(['id', 'public_title']) as $o) {
                $items[] = ['key' => 'business:'.$o->id, 'title' => $o->public_title, 'kind' => 'business'];
            }
        }

        return ['opportunities' => $items, 'search_limited' => count($items) > 50, 'sectors' => Sector::choices()->orderBy('name')->get(['id', 'name', 'slug']),
            'parks' => app(InvestmentZones::class)->visible()->where('category', 'industrial_park')->orderBy('name')->get(['id', 'name', 'version_no'])];
    }

    public function current(User $actor): array
    {
        if (! $this->installed()) {
            return ['installed' => false, 'focus' => null];
        }
        $p = DB::table('investor_navigation_preferences')->where('user_id', $actor->id)->first();
        if (! $p) {
            return ['installed' => true, 'focus' => null];
        }
        try {
            $case = $this->desk->case($actor, $p->case_id);
            app(InvestorPath::class)->view($actor, $case->id);
        } catch (ModelNotFoundException $e) {
            return ['installed' => true, 'focus' => null, 'message' => 'O contexto anterior já não está disponível para esta conta.'];
        } catch (HttpException $e) {
            if (in_array($e->getStatusCode(), [403, 404, 409], true)) {
                return ['installed' => true, 'focus' => null, 'message' => 'O contexto anterior já não está disponível para esta conta.'];
            }throw $e;
        }
        if ($case->closed_at) {
            return ['installed' => true, 'focus' => null];
        }

        return ['installed' => true, 'focus' => ['case_id' => $case->id, 'step_code' => $p->step_code, 'version' => (int) $p->version]];
    }

    public function focus(User $actor, array $input): array
    {
        abort_unless($this->installed(), 409, 'Instalação do contexto ainda pendente.');
        $data = Validator::make($input, ['case_id' => 'required|uuid', 'step_code' => ['nullable', 'regex:/^S(0[1-9]|1[0-9])$/'], 'version' => 'required|integer|min:0'])->validate();

        return DB::transaction(function () use ($actor, $data) {
            DB::table('users')->where('id', $actor->id)->lockForUpdate()->firstOrFail();
            $case = $this->desk->case($actor, $data['case_id']);
            abort_if($case->closed_at, 409);
            app(InvestorPath::class)->view($actor, $case->id);
            $old = DB::table('investor_navigation_preferences')->where('user_id', $actor->id)->first();
            $step = $data['step_code'] ?? null;
            if ($old && $old->case_id === $case->id && $old->step_code === $step) {
                return $this->current($actor);
            }
            abort_unless((int) ($old->version ?? 0) === $data['version'], 409, 'O contexto em foco mudou noutro dispositivo; recupere-o antes de escolher novamente.');
            DB::table('investor_navigation_preferences')->updateOrInsert(['user_id' => $actor->id], ['case_id' => $case->id, 'step_code' => $step, 'version' => (int) ($old->version ?? 0) + 1, 'updated_at' => now()]);

            return $this->current($actor);
        });
    }

    private function input(array $input): array
    {
        abort_if(array_diff(array_keys($input), ['version', 'selection', 'declarations', 'replace_fields', 'preview_hash', 'operation_key', 'confirm', '_token']), 422, 'Campo de controlo desconhecido.');

        return Validator::make($input, ['version' => 'required|integer|min:1', 'selection' => 'present|array:opportunity,sector,territory,park',
            'selection.*' => 'nullable|string|max:100', 'declarations' => 'nullable|array:project_title,project_summary', 'declarations.project_title' => 'nullable|string|max:200', 'declarations.project_summary' => 'nullable|string|max:5000',
            'replace_fields' => 'nullable|array', 'replace_fields.*' => 'string|in:'.implode(',', self::FIELDS)])->validate();
    }

    public function preview(User $actor, string $id, array $input): array
    {
        $data = $this->input($input);
        $case = $this->desk->case($actor, $id, true);
        abort_if($case->closed_at, 409);
        abort_unless((int) $case->version === $data['version'], 409, 'O dossier mudou; recupere a versão atual.');
        app(InvestorPath::class)->view($actor, $id);
        $old = $this->state($case);
        $selection = $old['selection'];
        foreach ($data['selection'] as $slot => $key) {
            if ($key === null || $key === '') {
                unset($selection[$slot]);

                continue;
            }
            $ref = $this->reference($key);
            $expected = $slot === 'opportunity' ? ['opportunity', 'business'] : [$slot];
            abort_unless(in_array($ref['kind'], $expected, true), 422, 'Referência incompatível com a dimensão.');
            $selection[$slot] = $ref;
        }
        // A new opportunity may propose its explicitly stored sector; it never matches names.
        if (isset($data['selection']['opportunity']) && ! array_key_exists('sector', $data['selection']) && isset($selection['opportunity']['fields']['sector_id'])) {
            if (Sector::where('is_active', true)->whereKey($selection['opportunity']['fields']['sector_id'])->exists()) {
                $selection['sector'] = $this->reference('sector:'.$selection['opportunity']['fields']['sector_id']);
            }
        }
        $proposed = [];
        $origins = [];
        foreach (['opportunity', 'sector', 'park', 'territory'] as $slot) {
            if (in_array($slot, ['park', 'territory'], true) && array_intersect(array_keys($selection[$slot]['fields'] ?? []), array_keys(InvestmentGeography::FIELDS))) {
                foreach (['province_id', 'district_id', 'admin_post_id', 'locality_id', 'province', 'district', 'location'] as $key) {
                    unset($proposed[$key],$origins[$key]);
                }
            }
            foreach ($selection[$slot]['fields'] ?? [] as $key => $value) {
                $proposed[$key] = (string) $value;
                $origins[$key] = Arr::except($selection[$slot], ['fields']);
            }
        }
        $fields = $old['fields'];
        $provenance = $old['provenance'];
        $changed = [];
        $kept = [];
        $replaced = [];
        foreach ($data['declarations'] ?? [] as $key => $value) {
            $fields[$key] = (string) ($value ?? '');
            $provenance[$key] = ['kind' => 'process_declaration', 'actor_id' => $actor->id, 'context_revision' => $old['revision'] + 1];
        }
        foreach ($proposed as $key => $value) {
            if (($fields[$key] ?? '') === '' || (($provenance[$key]['kind'] ?? '') !== 'process_declaration' && ($provenance[$key]['kind'] ?? '') !== 'dossier') || in_array($key, $data['replace_fields'] ?? [], true)) {
                if (($fields[$key] ?? null) !== $value) {
                    $replaced[] = ['field' => $key, 'before' => $fields[$key] ?? null, 'after' => $value];
                }$fields[$key] = $value;
                $provenance[$key] = $origins[$key];
            } else {
                $kept[] = ['field' => $key, 'value' => $fields[$key], 'proposed' => $value];
            }
        }
        // Remove inherited subordinate geography only when its source was actually replaced.
        foreach ($fields as $key => $value) {
            if (! array_key_exists($key, $proposed) && in_array($key, ['province_id', 'district_id', 'admin_post_id', 'locality_id', 'province', 'district', 'location', 'sector_id', 'sector'], true) && isset($provenance[$key]['key'])) {
                unset($fields[$key],$provenance[$key]);
            }
        }
        $replaced = [];
        foreach (array_unique([...array_keys($old['fields']), ...array_keys($fields)]) as $key) {
            if (($old['fields'][$key] ?? null) !== ($fields[$key] ?? null)) {
                $replaced[] = ['field' => $key, 'before' => $old['fields'][$key] ?? null, 'after' => $fields[$key] ?? null];
            }
        }
        foreach (['opportunity', 'sector', 'territory', 'park'] as $slot) {
            if (($old['selection'][$slot] ?? null) !== ($selection[$slot] ?? null)) {
                $changed[] = $slot;
            }
        }
        $dependencyChanged = $this->dependencyHash($old['selection']) !== $this->dependencyHash($selection);
        $payload = $this->desk->decode($case->payload);
        $results = $payload['investor_path']['results'] ?? [];
        $requests = DB::table('desk_requests')->where('case_id', $id)->orderBy('id')->get(['id', 'status', 'protocol', 'version'])->all();
        $steps = $dependencyChanged ? array_values(array_unique([...(array_intersect($changed, ['opportunity', 'sector']) ? ['S02', 'S03', 'S04', 'S08', 'S12', 'S13', 'S14', 'S15', 'S17'] : []), ...(array_intersect($changed, ['territory', 'park']) ? ['S08', 'S09', 'S10', 'S11', 'S17'] : [])])) : [];
        $plan = ['case_id' => $id, 'version' => (int) $case->version, 'revision' => (int) $old['revision'], 'selection' => $selection, 'fields' => $fields, 'provenance' => $provenance,
            'updated' => $replaced, 'maintained' => $kept, 'changed_dimensions' => $changed, 'dependent_results' => (int) $case->user_id === $actor->id && $dependencyChanged ? array_map(fn ($r) => ['id' => $r['id'], 'engine' => $r['engine']], $results) : [],
            'requests' => $requests, 'review_steps' => $steps, 'dependency_changed' => $dependencyChanged, 'documents_preserved' => DB::table('desk_documents')->where('case_id', $id)->count(),
            'notice' => 'Não confirma incentivos, licenças, disponibilidade de terra, reserva ou autorização. Submissões e decisões anteriores mantêm o conteúdo enviado.'];
        $hash = hash_hmac('sha256', json_encode(Arr::sortRecursive([$actor->id, $data, $plan]), JSON_THROW_ON_ERROR), config('app.key'));

        return [...$plan, 'preview_hash' => $hash];
    }

    public function commit(User $actor, string $id, array $input): array
    {
        abort_unless($this->installed(), 409, 'Instalação do contexto ainda pendente.');
        $control = Validator::make($input, ['preview_hash' => 'required|string|size:64', 'operation_key' => 'required|uuid', 'confirm' => 'required|accepted'])->validate();
        $this->input($input);
        $requestHash = hash('sha256', json_encode(Arr::sortRecursive($input), JSON_THROW_ON_ERROR));

        return DB::transaction(function () use ($actor, $id, $input, $control, $requestHash) {
            DB::select('SELECT pg_advisory_xact_lock(161026,hashtext(?))', [$control['operation_key']]);
            $receipt = DB::table('audit_events')->where('source_system', self::SOURCE)->where('correlation_id', $control['operation_key'])->first();
            if ($receipt) {
                $saved = json_decode($receipt->after_data, true);
                abort_unless((int) $receipt->actor_user_id === $actor->id && ($saved['case_id'] ?? '') === $id && hash_equals($saved['request_hash'], $requestHash), 409, 'Chave de operação usada com outro conteúdo ou ator.');
                $this->desk->case($actor, $id, true);

                return [...$saved['result'], 'replayed' => true];
            }
            $case = $this->desk->case($actor, $id, true, true);
            $before = $this->state($case);
            $plan = $this->preview($actor, $id, $input);
            abort_unless(hash_equals($plan['preview_hash'], $control['preview_hash']), 409, 'O dossier ou uma fonte mudou desde a prévia; compare novamente.');
            if (! $plan['changed_dimensions'] && ! $plan['updated'] && empty($input['declarations']) && empty($input['replace_fields'])) {
                $result = ['case_id' => $id, 'version' => (int) $case->version, 'revision' => $before['revision'], 'changed' => false, 'replayed' => false];
                DB::table('audit_events')->insert(['source_system' => self::SOURCE, 'entity_type' => 'desk_cases', 'entity_id' => $id, 'actor_user_id' => $actor->id, 'correlation_id' => $control['operation_key'], 'action' => 'context_unchanged', 'data_classification' => 'restricted', 'after_data' => json_encode(['case_id' => $id, 'request_hash' => $requestHash, 'result' => $result], JSON_THROW_ON_ERROR)]);

                return $result;
            }
            $payload = $this->desk->decode($case->payload);
            $revision = $before['revision'] + 1;
            $review = $before['review_steps'] ?? [];
            foreach ($plan['review_steps'] as $step) {
                $review[$step] = ['revision' => $revision, 'reason' => 'O contexto mudou; reveja os pressupostos e a evidência aplicável.'];
            }
            $context = ['revision' => $revision, 'selection' => $plan['selection'], 'fields' => $plan['fields'], 'provenance' => $plan['provenance'], 'review_steps' => $review,
                'dependency_hash' => $this->dependencyHash($plan['selection']), 'updated_at' => now()->toIso8601String(), 'updated_by' => $actor->id];
            if ($plan['dependency_changed']) {
                foreach ($payload['investor_path']['results'] ?? [] as $i => $r) {
                    $payload['investor_path']['results'][$i] = [...$r, 'context_state' => 'review_required', 'context_invalidated_revision' => $revision, 'context_invalidated_at' => now()->toIso8601String()];
                }
            }
            $payload['investor_path']['context'] = $context;
            DB::table('desk_cases')->where('id', $id)->update(['payload' => $this->desk->encode($payload), 'title' => $context['fields']['project_title'] ?? $case->title, 'version' => $case->version + 1, 'updated_at' => now()]);
            $this->desk->event($this->desk->case($actor, $id), $actor, 'investment_context_changed', ['before' => $before, 'after' => $context, 'affected_result_ids' => array_column($plan['dependent_results'], 'id'), 'preserved_request_ids' => array_column($plan['requests'], 'id')]);
            $result = ['case_id' => $id, 'version' => (int) $case->version + 1, 'revision' => $revision, 'replayed' => false];
            DB::table('audit_events')->insert(['source_system' => self::SOURCE, 'entity_type' => 'desk_cases', 'entity_id' => $id, 'actor_user_id' => $actor->id, 'correlation_id' => $control['operation_key'], 'action' => 'context_changed', 'data_classification' => 'restricted', 'after_data' => json_encode(['case_id' => $id, 'request_hash' => $requestHash, 'result' => $result], JSON_THROW_ON_ERROR)]);

            return $result;
        }, 3);
    }

    public function view(User $actor, string $id): array
    {
        $case = $this->desk->case($actor, $id);
        abort_unless($this->desk->owns($actor, $case, false) || $actor->can('manage-portal'), 403);
        $ctx = $this->state($case);
        $path = app(InvestorPath::class)->view($actor, $id);

        $simulatorRevision = null;
        if ((int) $case->user_id === $actor->id && $case->simulation_id) {
            $draftVersion = DB::table('simulation_form_drafts')->where('id', $case->simulation_id)->where('owner_user_id', $actor->id)->whereNull('deleted_at')->value('version_no');
            foreach (array_reverse($path['results']) as $result) {
                if (($result['draft_id'] ?? null) === $case->simulation_id && ($result['draft_version'] ?? null) === $draftVersion) {
                    $simulatorRevision = $result['context_revision'] ?? null;
                    break;
                }
            }
        }

        return ['simulator_context_revision' => $simulatorRevision, 'case' => $path['case'], 'context' => $ctx, 'steps' => array_map(fn ($s) => Arr::only($s, ['code', 'title', 'state', 'context_review_required']), $path['steps']),
            'can_write' => $path['canWrite'], 'next' => $path['next'], 'results' => $path['results'], 'requests' => $path['requests'],
            'prefill' => $this->prefill($ctx), 'notice' => 'A seleção apoia a preparação e não confirma benefícios, licenças, direitos ou disponibilidade.'];
    }

    public function prefill(array $ctx): array
    {
        $f = $ctx['fields'];
        $sim = Arr::only($f, ['project_title', 'project_summary', 'sector_id', 'province_id', 'district_id', 'admin_post_id', 'locality_id']);

        return ['simulator' => $sim, 'land' => array_filter(['project_reference' => $f['project_title'] ?? null, 'activity' => $f['sector'] ?? null, 'purpose' => $f['project_summary'] ?? null, 'parcels' => [Arr::only($f, array_keys(InvestmentGeography::FIELDS))]], fn ($v) => $v !== null),
            'desk' => array_filter(['title' => $f['project_title'] ?? null, 'territory_id' => $f['locality_id'] ?? $f['admin_post_id'] ?? $f['district_id'] ?? $f['province_id'] ?? null, 'location_source' => isset($f['province_id']) ? 'Referência consultada no contexto v'.($ctx['revision'] ?? 0).': '.($f['location'] ?? 'território identificado').'. Não confirma disponibilidade.' : null, 'description' => $f['project_summary'] ?? null, 'sector' => $f['sector'] ?? null, ...Arr::only($f, array_keys(InvestmentGeography::FIELDS))], fn ($v) => $v !== null),
            'submission' => array_filter(['sector' => $f['sector'] ?? null, 'objective' => $f['project_summary'] ?? null, 'location' => $f['location'] ?? null], fn ($v) => $v !== null)];
    }
}