<?php

namespace App\Models;

use CodeIgniter\Model;

class OperationModel extends Model
{
    protected $table         = 'operations';
    protected $primaryKey    = 'id';
    protected $returnType    = 'array';
    protected $useTimestamps = true;
    protected $allowedFields = ['date', 'amount', 'type', 'category_id', 'description'];

    protected $validationRules = [
        'date'        => 'required|valid_date[Y-m-d]',
        'amount'      => 'required|decimal|greater_than[0]',
        'type'        => 'required|in_list[income,expense]',
        'category_id' => 'permit_empty|is_natural_no_zero',
        'description' => 'permit_empty|max_length[255]',
    ];

    /**
     * Lista operacji z nazwa kategorii, z filtrami.
     * $f: from, to, category_id, type (wszystkie opcjonalne).
     */
    public function filtered(array $f): array
    {
        $b = $this->db->table('operations o')
            ->select('o.*, c.name AS category_name, p.name AS parent_name')
            ->join('categories c', 'c.id = o.category_id', 'left')
            ->join('categories p', 'p.id = c.parent_id', 'left');

        if (! empty($f['from'])) {
            $b->where('o.date >=', $f['from']);
        }
        if (! empty($f['to'])) {
            $b->where('o.date <=', $f['to']);
        }
        if (! empty($f['category_id'])) {
            $b->where('o.category_id', (int) $f['category_id']);
        }
        if (! empty($f['type'])) {
            $b->where('o.type', $f['type']);
        }

        return $b->orderBy('o.date', 'DESC')->orderBy('o.id', 'DESC')->get()->getResultArray();
    }

    /**
     * Sumy przychodow/wydatkow/salda dla zakresu (i opcjonalnych filtrow).
     */
    public function totals(array $f): array
    {
        $b = $this->db->table('operations o')
            ->select("SUM(CASE WHEN o.type='income' THEN o.amount ELSE 0 END) AS income")
            ->select("SUM(CASE WHEN o.type='expense' THEN o.amount ELSE 0 END) AS expense");

        if (! empty($f['from'])) {
            $b->where('o.date >=', $f['from']);
        }
        if (! empty($f['to'])) {
            $b->where('o.date <=', $f['to']);
        }
        if (! empty($f['category_id'])) {
            $b->where('o.category_id', (int) $f['category_id']);
        }
        if (! empty($f['type'])) {
            $b->where('o.type', $f['type']);
        }

        $row     = $b->get()->getRowArray() ?: [];
        $income  = (float) ($row['income'] ?? 0);
        $expense = (float) ($row['expense'] ?? 0);

        return [
            'income'  => $income,
            'expense' => $expense,
            'balance' => $income - $expense,
        ];
    }

    /**
     * Bilans miesieczny: [ ['ym'=>'2026-07','income'=>..,'expense'=>..], ... ].
     */
    public function monthlyBalance(string $from, string $to): array
    {
        return $this->db->table('operations')
            ->select("DATE_FORMAT(date, '%Y-%m') AS ym")
            ->select("SUM(CASE WHEN type='income' THEN amount ELSE 0 END) AS income")
            ->select("SUM(CASE WHEN type='expense' THEN amount ELSE 0 END) AS expense")
            ->where('date >=', $from)->where('date <=', $to)
            ->groupBy('ym')->orderBy('ym', 'ASC')
            ->get()->getResultArray();
    }

    /**
     * Suma wg kategorii dla danego typu: [ ['name'=>..,'total'=>..], ... ].
     */
    public function byCategory(string $from, string $to, string $type): array
    {
        $rows = $this->db->table('operations o')
            ->select('o.category_id, c.name AS cat_name, p.name AS parent_name, SUM(o.amount) AS total')
            ->join('categories c', 'c.id = o.category_id', 'left')
            ->join('categories p', 'p.id = c.parent_id', 'left')
            ->where('o.type', $type)
            ->where('o.date >=', $from)->where('o.date <=', $to)
            ->groupBy('o.category_id')->groupBy('c.name')->groupBy('p.name')
            ->orderBy('total', 'DESC')
            ->get()->getResultArray();

        // Etykieta = pelna sciezka kategoria -> podkategoria
        foreach ($rows as &$r) {
            if (empty($r['cat_name'])) {
                $r['name'] = '(bez kategorii)';
            } elseif (! empty($r['parent_name'])) {
                $r['name'] = $r['parent_name'] . ' → ' . $r['cat_name'];
            } else {
                $r['name'] = $r['cat_name'];
            }
        }

        return $rows;
    }

    /**
     * Saldo skumulowane w czasie: [ ['date'=>..,'balance'=>..], ... ].
     */
    public function runningBalance(string $from, string $to): array
    {
        $rows = $this->db->table('operations')
            ->select('date')
            ->select("SUM(CASE WHEN type='income' THEN amount ELSE -amount END) AS net")
            ->where('date >=', $from)->where('date <=', $to)
            ->groupBy('date')->orderBy('date', 'ASC')
            ->get()->getResultArray();

        $balance = 0.0;
        $out     = [];
        foreach ($rows as $r) {
            $balance += (float) $r['net'];
            $out[] = ['date' => $r['date'], 'balance' => round($balance, 2)];
        }

        return $out;
    }
}