<?php

namespace App\Actions\Tickets;

use App\Actions\Notifications\BuildTicketAssigneeChangedPayload;
use App\Actions\Notifications\TicketAssigneeChanged;
use App\Actions\Tickets\Support\AcceptanceCriteriaChecklistMapper;
use App\Enums\TicketWorklogEntryType;
use App\Models\Ticket;
use App\Models\TicketFieldDefinition;
use App\Models\TicketFieldValue;
use App\Models\User;
use Carbon\CarbonImmutable;
use Illuminate\Support\Arr;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\DB;

class UpdateProjectTicket
{
    public function __construct(
        private readonly BuildTicketAssigneeChangedPayload $buildTicketAssigneeChangedPayload,
        private readonly CreateTicketWorklogEntry $createTicketWorklogEntry,
        private readonly SyncProjectTicketFieldValues $syncProjectTicketFieldValues,
    ) {}

    /**
     * @param  array{
     *     acceptance_criteria: array<int, array{
     *         checked: bool,
     *         indent: int,
     *         text: string
     *     }>,
     *     assignee_user_id?: int|null,
     *     author_user_id?: int|null,
     *     blocked_comment: string|null,
     *     description: string|null,
     *     field_values?: array<int, array{
     *         ticket_field_definition_id: int,
     *         value_number?: float|int|string|null,
     *         value_user_id?: int|string|null
     *     }>,
     *     is_blocked: bool,
     *     story_points?: int|null,
     *     ticket_priority_id: int,
     *     ticket_type_id: int,
     *     parent_ticket_id: int|null,
     *     title: string
     * }  $validated
     */
    public function handle(
        Ticket $ticket,
        User $actor,
        array $validated,
        bool $replaceCriteriaWithIds = false,
    ): bool {
        $fieldValueAttributes = Arr::get($validated, 'field_values', []);
        $nextAcceptanceCriteria = AcceptanceCriteriaChecklistMapper::normalize(
            Arr::get($validated, 'acceptance_criteria'),
        );
        $ticketAttributes = $this->buildTicketAttributes($ticket, $validated);

        return DB::transaction(function () use ($actor, $fieldValueAttributes, $nextAcceptanceCriteria, $replaceCriteriaWithIds, $ticket, $ticketAttributes): bool {
            if (! $ticketAttributes['is_blocked']) {
                $ticketAttributes['blocked_comment'] = null;
            }

            $ticket->loadMissing([
                'assignee',
                'author',
                'acceptanceCriteria',
                'fieldValues.ticketFieldDefinition',
                'fieldValues.userValue',
                'parentTicket',
                'project',
                'ticketPriority',
                'ticketStatus.boardColumn',
                'ticketType',
            ]);

            /** @var Collection<int, TicketFieldDefinition> $fieldDefinitions */
            $fieldDefinitions = $ticket->project->ticketFieldDefinitions()
                ->get()
                ->keyBy('id');

            $ticketTypeOptions = $ticket->project->ticketTypes()
                ->get()
                ->keyBy('id');
            $ticketPriorityOptions = $ticket->project->ticketPriorities()
                ->get()
                ->keyBy('id');

            /** @var Collection<int, TicketFieldValue> $existingFieldValues */
            $existingFieldValues = $ticket->fieldValues
                ->keyBy('ticket_field_definition_id');
            $currentAcceptanceCriteria = $replaceCriteriaWithIds
                ? AcceptanceCriteriaChecklistMapper::fromModelsWithIds($ticket->acceptanceCriteria)
                : AcceptanceCriteriaChecklistMapper::fromModels($ticket->acceptanceCriteria);

            $changes = [];
            $summaryLabels = [];
            $assigneeChange = null;

            $this->trackScalarChange(
                $changes,
                $summaryLabels,
                'title',
                'title',
                $ticket->title,
                $ticketAttributes['title'],
            );
            $this->trackScalarChange(
                $changes,
                $summaryLabels,
                'description',
                'description',
                $ticket->description,
                $ticketAttributes['description'],
            );
            $this->trackAcceptanceCriteriaChange(
                $changes,
                $summaryLabels,
                $currentAcceptanceCriteria,
                $nextAcceptanceCriteria,
            );
            $this->trackScalarChange(
                $changes,
                $summaryLabels,
                'blocked_comment',
                'blocker comment',
                $ticket->blocked_comment,
                $ticketAttributes['blocked_comment'],
            );
            $this->trackNumberChange(
                $changes,
                $summaryLabels,
                'story_points',
                'story points',
                $ticket->story_points,
                $ticketAttributes['story_points'],
            );

            if ($ticket->ticket_type_id !== $ticketAttributes['ticket_type_id']) {
                $changes['ticket_type'] = [
                    'from' => $ticket->ticketType?->name,
                    'to' => $ticketTypeOptions->get($ticketAttributes['ticket_type_id'])?->name,
                ];
                $summaryLabels[] = 'type';
            }

            if ($ticket->ticket_priority_id !== $ticketAttributes['ticket_priority_id']) {
                $changes['ticket_priority'] = [
                    'from' => $ticket->ticketPriority?->name,
                    'to' => $ticketPriorityOptions->get($ticketAttributes['ticket_priority_id'])?->name,
                ];
                $summaryLabels[] = 'priority';
            }

            if ($ticket->is_blocked !== $ticketAttributes['is_blocked']) {
                $changes['is_blocked'] = [
                    'from' => $ticket->is_blocked,
                    'to' => $ticketAttributes['is_blocked'],
                ];
                $summaryLabels[] = 'blocked state';
            }

            if ($ticket->parent_ticket_id !== $ticketAttributes['parent_ticket_id']) {
                $newParentTicket = $ticketAttributes['parent_ticket_id'] === null
                    ? null
                    : Ticket::query()->find($ticketAttributes['parent_ticket_id']);

                $changes['parent_ticket'] = [
                    'from' => $ticket->parentTicket?->ticket_key,
                    'to' => $newParentTicket?->ticket_key,
                ];
                $summaryLabels[] = 'parent ticket';
            }

            if ($ticket->assignee_user_id !== $ticketAttributes['assignee_user_id']) {
                $toAssigneeId = $ticketAttributes['assignee_user_id'];
                $toAssigneeName = $toAssigneeId === null
                    ? null
                    : User::query()->find($toAssigneeId)?->name;

                $changes['assignee'] = [
                    'from' => $ticket->assignee?->name,
                    'to' => $toAssigneeName,
                ];
                $summaryLabels[] = 'assignee';

                $assigneeChange = [
                    'from_id' => $ticket->assignee_user_id,
                    'from_name' => $ticket->assignee?->name,
                    'to_id' => $toAssigneeId,
                    'to_name' => $toAssigneeName,
                ];
            }

            if ($ticket->author_user_id !== $ticketAttributes['author_user_id']) {
                $changes['author'] = [
                    'from' => $ticket->author?->name,
                    'to' => $ticketAttributes['author_user_id'] === null
                        ? null
                        : User::query()->find($ticketAttributes['author_user_id'])?->name,
                ];
                $summaryLabels[] = 'author';
            }

            $ticket->fill($ticketAttributes);

            if ($ticket->isDirty()) {
                $ticket->save();
            }

            if ($currentAcceptanceCriteria !== $nextAcceptanceCriteria) {
                AcceptanceCriteriaChecklistMapper::syncTicket($ticket, $nextAcceptanceCriteria, ! $replaceCriteriaWithIds);
            }

            $fieldValueChangeSet = $this->syncProjectTicketFieldValues->handle(
                $ticket,
                $fieldDefinitions,
                $existingFieldValues,
                $fieldValueAttributes,
            );

            if ($fieldValueChangeSet['changes'] !== []) {
                $changes['field_values'] = $fieldValueChangeSet['changes'];
                $summaryLabels = [
                    ...$summaryLabels,
                    ...$fieldValueChangeSet['summary_labels'],
                ];
            }

            if ($summaryLabels === []) {
                return false;
            }

            $this->createTicketWorklogEntry->handle(
                $ticket->fresh(),
                $actor,
                TicketWorklogEntryType::Updated,
                $this->buildSummary($summaryLabels),
                $changes,
            );

            if ($assigneeChange !== null) {
                TicketAssigneeChanged::dispatch(
                    $this->buildTicketAssigneeChangedPayload->handle(
                        $ticket->project,
                        $ticket,
                        $actor,
                        $assigneeChange['from_id'],
                        $assigneeChange['from_name'],
                        $assigneeChange['to_id'],
                        $assigneeChange['to_name'],
                        CarbonImmutable::now(),
                    ),
                );
            }

            return true;
        });
    }

    /**
     * @param  array{
     *     acceptance_criteria: array<int, array{
     *         checked: bool,
     *         indent: int,
     *         text: string
     *     }>,
     *     assignee_user_id?: int|null,
     *     author_user_id?: int|null,
     *     blocked_comment: string|null,
     *     description: string|null,
     *     is_blocked: bool,
     *     parent_ticket_id: int|null,
     *     story_points?: int|null,
     *     ticket_priority_id: int,
     *     ticket_type_id: int,
     *     title: string
     * }  $validated
     * @return array{
     *     assignee_user_id: int|null,
     *     author_user_id: int|null,
     *     blocked_comment: string|null,
     *     description: string|null,
     *     is_blocked: bool,
     *     parent_ticket_id: int|null,
     *     story_points: int|null,
     *     ticket_priority_id: int,
     *     ticket_type_id: int,
     *     title: string
     * }
     */
    private function buildTicketAttributes(Ticket $ticket, array $validated): array
    {
        return [
            'assignee_user_id' => Arr::exists($validated, 'assignee_user_id')
                ? Arr::get($validated, 'assignee_user_id')
                : $ticket->assignee_user_id,
            'author_user_id' => Arr::exists($validated, 'author_user_id')
                ? Arr::get($validated, 'author_user_id')
                : $ticket->author_user_id,
            'blocked_comment' => Arr::get($validated, 'blocked_comment'),
            'description' => Arr::get($validated, 'description'),
            'is_blocked' => Arr::get($validated, 'is_blocked', false),
            'parent_ticket_id' => Arr::get($validated, 'parent_ticket_id'),
            'story_points' => Arr::exists($validated, 'story_points')
                ? Arr::get($validated, 'story_points')
                : $ticket->story_points,
            'ticket_priority_id' => Arr::get($validated, 'ticket_priority_id'),
            'ticket_type_id' => Arr::get($validated, 'ticket_type_id'),
            'title' => Arr::get($validated, 'title'),
        ];
    }

    /**
     * @param  array<string, mixed>  $changes
     * @param  array<int, string>  $summaryLabels
     * @param  array<int, array{checked: bool, indent: int, text: string}>  $currentValue
     * @param  array<int, array{checked: bool, indent: int, text: string}>  $newValue
     */
    private function trackAcceptanceCriteriaChange(
        array &$changes,
        array &$summaryLabels,
        array $currentValue,
        array $newValue,
    ): void {
        if ($currentValue === $newValue) {
            return;
        }

        $changes['acceptance_criteria'] = [
            'from' => $currentValue,
            'to' => $newValue,
        ];
        $summaryLabels[] = 'acceptance criteria';
    }

    /**
     * @param  array<string, mixed>  $changes
     * @param  array<int, string>  $summaryLabels
     */
    private function trackScalarChange(
        array &$changes,
        array &$summaryLabels,
        string $changeKey,
        string $summaryLabel,
        ?string $currentValue,
        ?string $newValue,
    ): void {
        if ($currentValue === $newValue) {
            return;
        }

        $changes[$changeKey] = [
            'from' => $currentValue,
            'to' => $newValue,
        ];
        $summaryLabels[] = $summaryLabel;
    }

    /**
     * @param  array<string, mixed>  $changes
     * @param  array<int, string>  $summaryLabels
     */
    private function trackNumberChange(
        array &$changes,
        array &$summaryLabels,
        string $changeKey,
        string $summaryLabel,
        ?int $currentValue,
        ?int $newValue,
    ): void {
        if ($currentValue === $newValue) {
            return;
        }

        $changes[$changeKey] = [
            'from' => $currentValue,
            'to' => $newValue,
        ];
        $summaryLabels[] = $summaryLabel;
    }

    /**
     * @param  array<int, string>  $summaryLabels
     */
    private function buildSummary(array $summaryLabels): string
    {
        $uniqueLabels = collect($summaryLabels)
            ->unique()
            ->values();

        if ($uniqueLabels->count() === 1) {
            return 'Updated '.$uniqueLabels->first().'.';
        }

        if ($uniqueLabels->count() === 2) {
            return 'Updated '.$uniqueLabels->first().' and '.$uniqueLabels->last().'.';
        }

        $lastLabel = $uniqueLabels->pop();

        return 'Updated '.$uniqueLabels->implode(', ').', and '.$lastLabel.'.';
    }
}