<?php

namespace App\Actions\Tickets;

use App\Models\Ticket;
use App\Models\TicketFieldDefinition;
use App\Models\TicketFieldValue;
use App\Models\User;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\DB;

class UpdateProjectTicket
{
    public function __construct(
        private readonly CreateTicketWorklogEntry $createTicketWorklogEntry,
    ) {}

    /**
     * @param  array{
     *     acceptance_criteria: string|null,
     *     description: string|null,
     *     ticket_priority_id: int,
     *     ticket_type_id: int,
     *     title: string
     * }  $ticketAttributes
     * @param  array<int, array{
     *     ticket_field_definition_id: int,
     *     value_number?: float|int|string|null,
     *     value_user_id?: int|string|null
     * }>  $fieldValueAttributes
     */
    public function handle(
        Ticket $ticket,
        User $actor,
        array $ticketAttributes,
        array $fieldValueAttributes,
    ): bool {
        return DB::transaction(function () use ($actor, $fieldValueAttributes, $ticket, $ticketAttributes): bool {
            $ticket->loadMissing([
                'fieldValues.ticketFieldDefinition',
                'fieldValues.userValue',
                'parentTicket',
                'project',
                'ticketPriority',
                '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');

            $changes = [];
            $summaryLabels = [];

            $this->trackScalarChange(
                $changes,
                $summaryLabels,
                'title',
                'title',
                $ticket->title,
                $ticketAttributes['title'],
            );
            $this->trackScalarChange(
                $changes,
                $summaryLabels,
                'description',
                'description',
                $ticket->description,
                $ticketAttributes['description'],
            );
            $this->trackScalarChange(
                $changes,
                $summaryLabels,
                'acceptance_criteria',
                'acceptance criteria',
                $ticket->acceptance_criteria,
                $ticketAttributes['acceptance_criteria'],
            );

            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->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';
            }

            $ticket->fill($ticketAttributes);

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

            foreach ($fieldValueAttributes as $fieldValueAttribute) {
                $fieldDefinition = $fieldDefinitions->get((int) $fieldValueAttribute['ticket_field_definition_id']);

                if ($fieldDefinition === null) {
                    continue;
                }

                $existingFieldValue = $existingFieldValues->get($fieldDefinition->id);

                if ($fieldDefinition->field_type === 'user') {
                    $this->syncUserFieldValue(
                        $changes,
                        $existingFieldValue,
                        $fieldDefinition,
                        $fieldValueAttribute,
                        $summaryLabels,
                        $ticket,
                    );

                    continue;
                }

                $this->syncNumberFieldValue(
                    $changes,
                    $existingFieldValue,
                    $fieldDefinition,
                    $fieldValueAttribute,
                    $summaryLabels,
                    $ticket,
                );
            }

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

            $this->createTicketWorklogEntry->handle(
                $ticket->fresh(),
                $actor,
                'updated',
                $this->buildSummary($summaryLabels),
                $changes,
            );

            return true;
        });
    }

    /**
     * @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{value_user_id?: int|string|null}  $fieldValueAttribute
     * @param  array<int, string>  $summaryLabels
     */
    private function syncUserFieldValue(
        array &$changes,
        ?TicketFieldValue $existingFieldValue,
        TicketFieldDefinition $fieldDefinition,
        array $fieldValueAttribute,
        array &$summaryLabels,
        Ticket $ticket,
    ): void {
        $newUserId = $fieldValueAttribute['value_user_id'] ?? null;
        $newUserId = $newUserId === null || $newUserId === '' ? null : (int) $newUserId;

        if ($existingFieldValue?->value_user_id === $newUserId) {
            return;
        }

        $oldUserName = $existingFieldValue?->userValue?->name;
        $newUserName = $newUserId === null ? null : User::query()->find($newUserId)?->name;

        $changes['field_values'][$fieldDefinition->id] = [
            'field' => $fieldDefinition->label,
            'from' => $oldUserName,
            'to' => $newUserName,
        ];
        $summaryLabels[] = "{$fieldDefinition->label} field";

        if ($newUserId === null) {
            $existingFieldValue?->delete();

            return;
        }

        $ticket->fieldValues()->updateOrCreate(
            [
                'ticket_field_definition_id' => $fieldDefinition->id,
            ],
            [
                'value_number' => null,
                'value_user_id' => $newUserId,
            ],
        );
    }

    /**
     * @param  array<string, mixed>  $changes
     * @param  array{value_number?: float|int|string|null}  $fieldValueAttribute
     * @param  array<int, string>  $summaryLabels
     */
    private function syncNumberFieldValue(
        array &$changes,
        ?TicketFieldValue $existingFieldValue,
        TicketFieldDefinition $fieldDefinition,
        array $fieldValueAttribute,
        array &$summaryLabels,
        Ticket $ticket,
    ): void {
        $newNumber = $fieldValueAttribute['value_number'] ?? null;
        $newNumber = $newNumber === null || $newNumber === '' ? null : (float) $newNumber;
        $oldNumber = $existingFieldValue?->value_number;

        if ($oldNumber === $newNumber) {
            return;
        }

        $changes['field_values'][$fieldDefinition->id] = [
            'field' => $fieldDefinition->label,
            'from' => $this->formatNumber($oldNumber),
            'to' => $this->formatNumber($newNumber),
        ];
        $summaryLabels[] = "{$fieldDefinition->label} field";

        if ($newNumber === null) {
            $existingFieldValue?->delete();

            return;
        }

        $ticket->fieldValues()->updateOrCreate(
            [
                'ticket_field_definition_id' => $fieldDefinition->id,
            ],
            [
                'value_number' => $newNumber,
                'value_user_id' => null,
            ],
        );
    }

    /**
     * @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.'.';
    }

    private function formatNumber(?float $value): ?string
    {
        if ($value === null) {
            return null;
        }

        return rtrim(rtrim(number_format($value, 2, '.', ''), '0'), '.');
    }
}