<?php

namespace App\Mcp\Support;

use App\Actions\Tickets\Support\AcceptanceCriteriaChecklistMapper;
use App\Http\Requests\UpdateProjectTicketRequest;
use App\Models\Ticket;
use App\Models\TicketFieldDefinition;
use App\Models\User;
use App\Rules\VisualTicketDescription;
use Illuminate\Routing\Route;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\Validator;
use Illuminate\Validation\Rule;
use Illuminate\Validation\ValidationException;
use Laravel\Mcp\Request;

class TicketUpdateInput
{
    public function __construct(private readonly KanbanGitMcp $kanbanGitMcp) {}

    /** @return array<string, mixed> */
    public function validate(Request $request, Ticket $ticket, User $user): array
    {
        $form = new UpdateProjectTicketRequest;
        $route = new Route('PUT', '/', fn () => null);
        $route->bind(\Illuminate\Http\Request::create('/', 'PUT'));
        $route->setParameter('project', $ticket->project);
        $route->setParameter('ticket', $ticket);
        $form->setRouteResolver(fn () => $route);
        $form->setUserResolver(fn () => $user);
        $rules = $form->rules();
        foreach ($rules as $key => &$rule) {
            if (! str_contains($key, '.')) {
                $rule = ['sometimes', ...$rule];
            }
        }
        unset($rule);
        $rules['description'][] = new VisualTicketDescription;
        $rules['acceptance_criteria'] = ['sometimes', 'array', 'list'];
        $rules['acceptance_criteria.*'] = ['array:id,text,checked,indent'];
        $rules['acceptance_criteria.*.id'] = ['sometimes', 'integer', 'min:1', 'distinct', Rule::exists('acceptance_criteria', 'id')->where('ticket_id', $ticket->id)];
        $rules['acceptance_criteria.*.checked'] = ['sometimes', 'boolean'];
        $rules['acceptance_criteria.*.indent'] = ['sometimes', 'integer', 'min:0', 'max:'.AcceptanceCriteriaChecklistMapper::MAX_INDENT_LEVEL];
        $rules['field_values'] = ['sometimes', 'array', 'list'];
        $rules['field_values.*'] = ['array:ticket_field_definition_id,value_number,value_user_id'];
        $rules['field_values.*.ticket_field_definition_id'][] = 'distinct';
        $rules['ticket_status_id'] = ['prohibited'];
        $rules['acceptance_criteria.*.text'][] = function (string $attribute, mixed $value, \Closure $fail): void {
            if (is_string($value) && trim($value) === '') {
                $fail('Criterion text must not be blank.');
            }
        };
        $input = $request->validate($rules);
        $previousIndent = -1;
        foreach (Arr::get($input, 'acceptance_criteria', []) as $index => $item) {
            $indent = Arr::get($item, 'indent', 0);
            if ($indent > $previousIndent + 1) {
                throw ValidationException::withMessages(["acceptance_criteria.{$index}.indent" => 'Indentation cannot skip a level; the first item must have indent 0.']);
            }
            $previousIndent = $indent;
        }
        $merged = array_replace($this->kanbanGitMcp->updatePayload($ticket), $input);
        $merged['acceptance_criteria'] = Arr::exists($input, 'acceptance_criteria')
            ? AcceptanceCriteriaChecklistMapper::normalize($input['acceptance_criteria'])
            : AcceptanceCriteriaChecklistMapper::fromModelsWithIds($ticket->acceptanceCriteria()->get());

        $validator = Validator::make($merged, $form->rules());
        $form->setValidator($validator);
        $validator->validate();
        foreach ($form->after() as $callback) {
            $callback($validator);
        }

        $people = User::query()->visibleToProject($ticket->project)->pluck('id')->all();
        foreach (['assignee_user_id', 'author_user_id'] as $field) {
            if (Arr::exists($input, $field) && $input[$field] !== null && ! in_array((int) $input[$field], $people, true)) {
                $validator->errors()->add($field, 'The person must be able to view this project.');
            }
        }
        $definitions = $ticket->project->ticketFieldDefinitions()->get()->keyBy('id');
        foreach (Arr::get($input, 'field_values', []) as $index => $value) {
            $definition = $definitions->get($value['ticket_field_definition_id']);
            $incompatible = $definition->field_type === 'user' ? 'value_number' : 'value_user_id';
            if (Arr::get($value, $incompatible) !== null) {
                $validator->errors()->add("field_values.{$index}.{$incompatible}", 'The value must match the custom field type.');
            }
            if (Arr::get($value, 'value_user_id') !== null && ! in_array((int) $value['value_user_id'], $people, true)) {
                $validator->errors()->add("field_values.{$index}.value_user_id", 'The person must be able to view this project.');
            }
        }
        if ($validator->errors()->isNotEmpty()) {
            throw new ValidationException($validator);
        }

        if (Arr::exists($input, 'field_values')) {
            $replacement = $definitions->map(fn (TicketFieldDefinition $definition): array => [
                'ticket_field_definition_id' => $definition->id,
                'value_number' => null,
                'value_user_id' => null,
            ])->all();
            foreach ($input['field_values'] as $value) {
                $replacement[$value['ticket_field_definition_id']] = $value;
            }
            $merged['field_values'] = array_values($replacement);
        }

        return $merged;
    }
}