<?php

namespace Kanboard\Plugin\FinanceBuddy\Model;

use Kanboard\Core\Base;
use Kanboard\Plugin\FinanceBuddy\Helper\FinanceHelper;

/**
 * Persists the FinanceBuddy fields that live in the core task form.
 *
 * PicoDb's insert()/update() build SQL straight from the value keys, so any non-column field left
 * in $values would break task saving (this is why core unset()s "tags"). We therefore:
 *   (a) strip every financebuddy_* key from $values in the create/modify "prepare" hooks, and
 *   (b) write the values to task metadata separately.
 *
 * Everything here runs synchronously inside the model call during the HTTP request (the "prepare"
 * and "aftersave" reference hooks), so it does NOT depend on the optionally-async event queue. The
 * finance values are read straight from $values (getValues() cannot be reused: the controller
 * already consumed the CSRF token). The task id comes from the aftersave hook (create) or the
 * route parameter (modify).
 */
class FinancePersistence extends Base
{
    private $pending = null;

    /**
     * model:task:creation:prepare -- fires before INSERT, $values by reference, no task id yet.
     */
    public function onCreationPrepare(array &$values)
    {
        $this->pending = null;

        if (isset($values[FinanceHelper::FORM_MARKER])) {
            $this->pending = array(
                'project_id' => isset($values['project_id']) ? (int) $values['project_id'] : 0,
                'fields' => $this->extract($values),
            );
        }

        $this->strip($values);
    }

    /**
     * model:task:creation:aftersave -- fires after INSERT, hands over the new task id by reference.
     */
    public function onCreationAfterSave(&$task_id)
    {
        if ($this->pending !== null) {
            $this->persist((int) $task_id, $this->pending['project_id'], $this->pending['fields']);
            $this->pending = null;
            return;
        }

        // Not a form submission. Native recurrence builds the next occurrence with a plain task
        // create (which copies no metadata) after setting recurrence_parent to the source task, so
        // carry the finance metadata across -- otherwise the recurring card loses its money.
        $task = $this->taskFinderModel->getById((int) $task_id);

        if (! empty($task['recurrence_parent'])) {
            // A recurrence is the NEXT occurrence, so advance the installment (p2/30 -> p3/30).
            $this->copyMetadata((int) $task['recurrence_parent'], (int) $task_id, true);
        }
    }

    /**
     * model:task:duplication:aftersave -- the manual "Duplicate" action. TaskDuplicationModel does
     * not copy metadata, so carry the finance fields to the new task.
     */
    public function onDuplication(array &$hook_values)
    {
        if (! empty($hook_values['source_task_id']) && ! empty($hook_values['destination_task_id'])) {
            $this->copyMetadata((int) $hook_values['source_task_id'], (int) $hook_values['destination_task_id']);
        }
    }

    /**
     * recoreco:task:spawned -- RecoReco (calendar recurrence) just spawned a copy. Its ongoing card
     * is the TEMPLATE that stays (unlike native recurrence, whose ongoing card is the new child), so
     * advance the SOURCE template's installment. The clone already copied the current installment
     * verbatim via onDuplication during RecoReco's duplicate() call.
     */
    public function onRecoRecoSpawn(array &$payload)
    {
        if (! empty($payload['source_task_id'])) {
            $this->advanceInstallment((int) $payload['source_task_id']);
        }
    }

    /**
     * model:task:modification:prepare -- fires before UPDATE, $values by reference. The task id is
     * removed from $values by core, but it is the route parameter of the modification request.
     */
    public function onModificationPrepare(array &$values)
    {
        if (isset($values[FinanceHelper::FORM_MARKER])) {
            $task_id = $this->request->getIntegerParam('task_id');
            $project_id = isset($values['project_id']) ? (int) $values['project_id'] : 0;

            if ($task_id > 0) {
                $this->persist($task_id, $project_id, $this->extract($values));
            }
        }

        $this->strip($values);
    }

    private function extract(array $values)
    {
        return array(
            'amount' => isset($values[FinanceHelper::AMOUNT_KEY]) ? $values[FinanceHelper::AMOUNT_KEY] : '',
            'direction' => (isset($values[FinanceHelper::DIRECTION_KEY]) && $values[FinanceHelper::DIRECTION_KEY] === 'credit') ? 'credit' : 'debit',
            'installment_current' => isset($values[FinanceHelper::INSTALLMENT_CURRENT_KEY]) ? $values[FinanceHelper::INSTALLMENT_CURRENT_KEY] : '',
            'installment_total' => isset($values[FinanceHelper::INSTALLMENT_TOTAL_KEY]) ? $values[FinanceHelper::INSTALLMENT_TOTAL_KEY] : '',
        );
    }

    private function strip(array &$values)
    {
        foreach (array_keys($values) as $key) {
            if (strpos($key, 'financebuddy_') === 0) {
                unset($values[$key]);
            }
        }
    }

    private function persist($task_id, $project_id, array $fields)
    {
        // Only touch metadata on boards where a manager opted in.
        if ((int) $this->projectMetadataModel->get($project_id, FinanceHelper::ENABLED_KEY, 0) !== 1) {
            return;
        }

        $amount = FinanceHelper::parseAmount($fields['amount']);

        // No (or cleared) amount: drop any finance metadata so the card goes back to plain.
        if ($amount <= 0) {
            foreach (array(FinanceHelper::AMOUNT_KEY, FinanceHelper::DIRECTION_KEY, FinanceHelper::INSTALLMENT_CURRENT_KEY, FinanceHelper::INSTALLMENT_TOTAL_KEY) as $key) {
                $this->taskMetadataModel->remove($task_id, $key);
            }

            return;
        }

        $this->taskMetadataModel->save($task_id, array(
            FinanceHelper::AMOUNT_KEY => number_format($amount, 2, '.', ''),
            FinanceHelper::DIRECTION_KEY => $fields['direction'] === 'credit' ? 'credit' : 'debit',
            FinanceHelper::INSTALLMENT_CURRENT_KEY => $this->intOrBlank($fields['installment_current']),
            FinanceHelper::INSTALLMENT_TOTAL_KEY => $this->intOrBlank($fields['installment_total']),
        ));
    }

    /**
     * Copy the finance metadata from one task to another (recurrence next occurrence, or a manual
     * duplicate). When $advance is true, bump the current installment by one -- clamped at the
     * total so a finite plan stops at its last installment (e.g. p30/30 stays p30/30).
     */
    private function copyMetadata($source_id, $dest_id, $advance = false)
    {
        if ($source_id <= 0 || $dest_id <= 0) {
            return;
        }

        $amount = $this->taskMetadataModel->get($source_id, FinanceHelper::AMOUNT_KEY, '');

        // Nothing to carry over if the source has no money set.
        if ($amount === '' || (float) $amount <= 0) {
            return;
        }

        $direction = $this->taskMetadataModel->get($source_id, FinanceHelper::DIRECTION_KEY, 'debit');
        $current = $this->taskMetadataModel->get($source_id, FinanceHelper::INSTALLMENT_CURRENT_KEY, '');
        $total = $this->taskMetadataModel->get($source_id, FinanceHelper::INSTALLMENT_TOTAL_KEY, '');

        if ($advance && $current !== '' && ctype_digit((string) $current)) {
            $next = (int) $current + 1;

            if ($total !== '' && ctype_digit((string) $total) && $next > (int) $total) {
                $next = (int) $total;
            }

            $current = (string) $next;
        }

        $this->taskMetadataModel->save($dest_id, array(
            FinanceHelper::AMOUNT_KEY => $amount,
            FinanceHelper::DIRECTION_KEY => $direction === 'credit' ? 'credit' : 'debit',
            FinanceHelper::INSTALLMENT_CURRENT_KEY => $current,
            FinanceHelper::INSTALLMENT_TOTAL_KEY => $total,
        ));
    }

    /**
     * Advance a task's current installment by one, in place. A finite plan clamps at the total
     * (p10/10 stays p10/10); an open-ended one (no total) increments unbounded (p2 -> p3). Cards
     * with no numeric current installment are left alone.
     */
    private function advanceInstallment($task_id)
    {
        $current = $this->taskMetadataModel->get($task_id, FinanceHelper::INSTALLMENT_CURRENT_KEY, '');

        if ($current === '' || ! ctype_digit((string) $current)) {
            return;
        }

        $total = $this->taskMetadataModel->get($task_id, FinanceHelper::INSTALLMENT_TOTAL_KEY, '');
        $next = (int) $current + 1;

        if ($total !== '' && ctype_digit((string) $total) && $next > (int) $total) {
            $next = (int) $total;
        }

        $this->taskMetadataModel->save($task_id, array(
            FinanceHelper::INSTALLMENT_CURRENT_KEY => (string) $next,
        ));
    }

    private function intOrBlank($raw)
    {
        $raw = trim((string) $raw);

        return ($raw !== '' && ctype_digit($raw) && (int) $raw > 0) ? (string) (int) $raw : '';
    }
}