<?php

namespace Modules\EcommerceFinance\Services;

use Illuminate\Support\Facades\File;

/**
 * 账套科目索引（resources/data/coa.json）。
 *
 * 账套是「小企业会计准则 + 5 位一级科目」，层级用点分：5601.05.04。
 * 映射表里写的是「一级科目名 + 二级科目名」两列，二级名往往是第 3、4 层，
 * 所以按「一级名 → 一级编码 → 编码前缀」这条路去子树里找，才找得准。
 */
class AccountMappingCoa
{
    /** @var array<int,array{code:string,name:string,level:int,category:string,balance:string}>|null */
    private ?array $accounts = null;

    /** @return array<int,array{code:string,name:string,level:int,category:string,balance:string}> */
    public function all(): array
    {
        if ($this->accounts !== null) {
            return $this->accounts;
        }

        $path = resource_path('data/coa.json');
        $payload = File::exists($path) ? json_decode((string) File::get($path), true) : null;
        $rows = is_array($payload['accounts'] ?? null) ? $payload['accounts'] : [];

        $this->accounts = array_map(static fn (array $row): array => [
            'code' => (string) ($row[0] ?? ''),
            'name' => (string) ($row[1] ?? ''),
            'level' => (int) ($row[2] ?? 1),
            'category' => (string) ($row[3] ?? ''),
            'balance' => (string) ($row[4] ?? ''),
        ], $rows);

        return $this->accounts;
    }

    /** @return array<int,array{code:string,name:string}> 一级科目（用于下拉第一级） */
    public function level1(): array
    {
        return array_values(array_map(
            static fn (array $a): array => ['code' => $a['code'], 'name' => $a['name']],
            array_filter($this->all(), static fn (array $a): bool => $a['level'] === 1 && $a['name'] !== '')
        ));
    }

    /** @return array<int,array{code:string,name:string,level:int}> 某编码子树下的非一级科目 */
    public function descendants(string $code): array
    {
        if ($code === '') {
            return [];
        }

        $prefix = $code . '.';
        $hits = [];
        foreach ($this->all() as $a) {
            if ($a['code'] !== $code && str_starts_with($a['code'], $prefix)) {
                $hits[] = ['code' => $a['code'], 'name' => $a['name'], 'level' => $a['level']];
            }
        }

        return $hits;
    }

    /** 一级科目名 → 编码（账套里一级科目名唯一） */
    public function level1Code(string $name): ?string
    {
        $name = trim($name);
        if ($name === '') {
            return null;
        }

        foreach ($this->all() as $a) {
            if ($a['level'] === 1 && $a['name'] === $name) {
                return $a['code'];
            }
        }

        return null;
    }

    /**
     * 在「一级科目」子树下按名称找科目编码。
     *
     * @return array<int,string> 命中编码；空数组 = 不存在；多于 1 个 = 同名歧义
     */
    public function resolve(string $level1Name, string $subName): array
    {
        $subName = trim($subName);
        if ($subName === '') {
            return [];
        }

        $base = $this->level1Code($level1Name);
        if ($base === null) {
            return [];
        }

        $hits = [];
        foreach ($this->all() as $a) {
            if ($a['name'] === $subName && ($a['code'] === $base || str_starts_with($a['code'], $base . '.'))) {
                $hits[] = $a['code'];
            }
        }

        sort($hits);

        return $hits;
    }

    /** 全账套里同名的编码（用于解释「为什么找不到」） @return array<int,string> */
    public function anywhereByName(string $name): array
    {
        $name = trim($name);
        if ($name === '') {
            return [];
        }

        $hits = [];
        foreach ($this->all() as $a) {
            if ($a['name'] === $name) {
                $hits[] = $a['code'];
            }
        }

        sort($hits);

        return $hits;
    }

    /** 名称或编码 → 编码（映射表里偶尔会直接写编码） */
    public function toCode(string $level1Token): ?string
    {
        $token = trim($level1Token);
        if ($token === '') {
            return null;
        }

        if (preg_match('/^\d+(\.\d+)*$/', $token) === 1) {
            foreach ($this->all() as $a) {
                if ($a['code'] === $token) {
                    return $token;
                }
            }

            return null;
        }

        return $this->level1Code($token);
    }
}