<?php

namespace Modules\EcommerceFinance\Services;

use Illuminate\Support\Facades\File;
use Illuminate\Support\Carbon;
use RuntimeException;

/**
 * 科目映射表存储。
 *
 * 一条规则 = 「走哪两个科目（科目对）」+「方向基准」，**不存最终借贷方向**。
 * 记账时按这张账单在平台上的实际收支代入：
 *   账单收支 === 基准方向 → 照抄；否则 → 借贷互换。
 *
 * 当前落盘在 storage/app/account-mapping/rules.json（持久卷，重启不丢），
 * 首次访问会用 resources/data/account-mapping.json 作为初始 112 条规则灌入。
 * 若要变成正式的数据表，只需替换本类的读写实现，页面与接口不用动。
 *
 * 时间统一按 config('app.platform_timezone')（= APP_TIMEZONE）落盘，不能用 now()：
 * 页面请求会被 App\Utilities\Overrider 按公司设置覆盖 app.timezone，ak_settings 里没有
 * localisation.timezone 时回落成 Europe/London，会让记录时间比北京时间晚 7 小时。
 */
class AccountMappingStore
{
    /** 可维护字段（顺序即导出/模板列顺序） */
    public const FIELDS = ['platform', 'item', 'memo', 'goods', 'invoice', 'category', 'dAcct', 'dSub', 'cAcct', 'cSub', 'basis'];

    public const LABELS = [
        'platform' => '平台',
        'item' => '账单项目',
        'memo' => '财务备注',
        'goods' => '商品名称关键词',
        'invoice' => '票据口径',
        'category' => '财务类型',
        'dAcct' => '借方科目',
        'dSub' => '借方二级',
        'cAcct' => '贷方科目',
        'cSub' => '贷方二级',
        'basis' => '方向基准',
    ];

    public const BASIS_OUT = '支出基准';
    public const BASIS_IN = '收入基准';

    public const BASISES = [self::BASIS_OUT, self::BASIS_IN];

    /** 大类 → 预期方向基准（用于校验「基准与大类是否一致」） */
    public const CATEGORY_BASIS = [
        '费用' => self::BASIS_OUT,
        '售后费用' => self::BASIS_OUT,
        '平台服务费' => self::BASIS_OUT,
        '平台佣金' => self::BASIS_OUT,
        '推广' => self::BASIS_OUT,
        '保证金' => self::BASIS_OUT,
        '暂挂' => self::BASIS_OUT,
        '待处理财产损益' => self::BASIS_OUT,
        '营业外支出' => self::BASIS_OUT,
        '税费' => self::BASIS_OUT,
        '提现' => self::BASIS_OUT,
        '收入' => self::BASIS_IN,
        '往来' => self::BASIS_IN,
        '转账' => self::BASIS_IN,
    ];

    /** 票据口径可取值 */
    public const INVOICES = ['0.06', '0.09', '不开票', '-'];

    /**
     * 存储目录。
     *
     * 用 storage 而不是 runtime：预览/生产容器都只挂了仓库的若干子目录，
     * runtime/ 不在挂载范围内（写了会落在容器自己那层，重建就丢）；
     * storage/app 是 Laravel 规范可写目录，且挂的是持久卷。
     */
    public function dir(): string
    {
        return storage_path('app/account-mapping');
    }

    public function path(): string
    {
        return $this->dir() . DIRECTORY_SEPARATOR . 'rules.json';
    }

    public function eventPath(): string
    {
        return $this->dir() . DIRECTORY_SEPARATOR . 'events.json';
    }

    /** @return array<int,array<string,mixed>> 按 id 升序的全部规则 */
    public function all(): array
    {
        $this->ensureSeeded();

        $payload = $this->read($this->path());
        $rules = is_array($payload['rules'] ?? null) ? $payload['rules'] : [];

        $rules = array_values(array_filter($rules, static fn (mixed $r): bool => is_array($r) && isset($r['id'])));
        usort($rules, static fn (array $a, array $b): int => ((int) $a['id']) <=> ((int) $b['id']));

        return $rules;
    }

    public function find(int $id): ?array
    {
        foreach ($this->all() as $rule) {
            if ((int) $rule['id'] === $id) {
                return $rule;
            }
        }

        return null;
    }

    /** 新增一条，返回新规则 */
    public function create(array $values, ?int $userId = null): array
    {
        $rules = $this->all();
        $id = 1;
        foreach ($rules as $rule) {
            $id = max($id, ((int) $rule['id']) + 1);
        }

        $rule = ['id' => $id] + $this->normalize($values);
        $rules[] = $rule;
        $this->persist($rules);
        $this->logEvent('create', $id, null, $rule, $userId);

        return $rule;
    }

    /** 修改一条，返回改后的规则 */
    public function update(int $id, array $values, ?int $userId = null): array
    {
        $rules = $this->all();
        $updated = null;
        $before = null;

        foreach ($rules as $index => $rule) {
            if ((int) $rule['id'] !== $id) {
                continue;
            }
            $before = $rule;
            $updated = ['id' => $id] + $this->normalize(array_replace($rule, $values));
            $rules[$index] = $updated;
            break;
        }

        if ($updated === null) {
            throw new RuntimeException('未找到要修改的规则。');
        }

        $this->persist($rules);
        $this->logEvent('update', $id, $before, $updated, $userId);

        return $updated;
    }

    public function destroy(int $id, ?int $userId = null): bool
    {
        $rules = $this->all();
        $before = null;
        $kept = [];

        foreach ($rules as $rule) {
            if ((int) $rule['id'] === $id) {
                $before = $rule;
                continue;
            }
            $kept[] = $rule;
        }

        if ($before === null) {
            return false;
        }

        $this->persist($kept);
        $this->logEvent('delete', $id, $before, null, $userId);

        return true;
    }

    /**
     * 导入：按「平台 + 账单项目 + 财务备注」判重。
     *
     * @param array<int,array<string,mixed>> $rows
     * @return array{created:int,updated:int,skipped:int,duplicates:array<int,string>,total:int}
     */
    public function importRows(array $rows, bool $overwrite, ?int $userId = null): array
    {
        $rules = $this->all();
        $byKey = [];
        foreach ($rules as $index => $rule) {
            $byKey[$this->keyOf($rule)] = $index;
        }
        $nextId = 1;
        foreach ($rules as $rule) {
            $nextId = max($nextId, ((int) $rule['id']) + 1);
        }

        $created = 0;
        $updated = 0;
        $skipped = 0;
        $duplicates = [];

        foreach ($rows as $row) {
            $values = $this->normalize($row);
            if ($this->isEmptyRow($values)) {
                continue;
            }

            $key = $this->keyOf($values);
            if (isset($byKey[$key])) {
                if (! $overwrite) {
                    $skipped++;
                    $duplicates[] = $key;
                    continue;
                }
                $index = $byKey[$key];
                $rules[$index] = ['id' => $rules[$index]['id']] + $values;
                $updated++;
                continue;
            }

            $rules[] = ['id' => $nextId] + $values;
            $byKey[$key] = count($rules) - 1;
            $nextId++;
            $created++;
        }

        if ($created + $updated > 0) {
            $this->persist($rules);
            $this->logEvent('import', null, null, null, $userId, [
                'created' => $created,
                'updated' => $updated,
                'skipped' => $skipped,
            ]);
        }

        return [
            'created' => $created,
            'updated' => $updated,
            'skipped' => $skipped,
            'duplicates' => array_slice($duplicates, 0, 20),
            'total' => count($rows),
        ];
    }

    /** 用 resources/data/account-mapping.json 覆盖回初始状态 */
    public function reset(?int $userId = null): int
    {
        $seed = $this->seed();
        $this->persist($seed);
        $this->logEvent('reset', null, null, null, $userId, ['total' => count($seed)]);

        return count($seed);
    }

    /** @return array<int,array<string,mixed>> */
    public function seed(): array
    {
        $path = resource_path('data/account-mapping.json');
        $payload = File::exists($path) ? json_decode((string) File::get($path), true) : null;

        // 种子文件既可能是顶层数组，也可能是 {"rules": [...]}，两种都认
        $rows = [];
        if (is_array($payload)) {
            if (is_array($payload['rules'] ?? null)) {
                $rows = $payload['rules'];
            } elseif (array_is_list($payload)) {
                $rows = $payload;
            }
        }

        $out = [];
        foreach ($rows as $row) {
            if (! is_array($row)) {
                continue;
            }
            $out[] = ['id' => (int) ($row['no'] ?? (count($out) + 1))] + $this->normalize($row);
        }
        usort($out, static fn (array $a, array $b): int => ((int) $a['id']) <=> ((int) $b['id']));

        return $out;
    }

    /** @return array<string,string> */
    public function normalize(array $values): array
    {
        $out = [];
        foreach (self::FIELDS as $field) {
            $value = $values[$field] ?? '';
            if (is_array($value) || is_object($value)) {
                $value = '';
            }
            $out[$field] = trim((string) $value);
        }

        if (! in_array($out['basis'], self::BASISES, true)) {
            $out['basis'] = self::CATEGORY_BASIS[$out['category']] ?? self::BASIS_OUT;
        }

        // 区分条件里的「-」「—」表示“不限”，按空处理：否则匹配时会拿它去找关键词，规则永远命中不了
        foreach (['memo', 'goods'] as $field) {
            if (in_array($out[$field], ['-', '—', '－'], true)) {
                $out[$field] = '';
            }
        }

        return $out;
    }

    /**
     * 判重键：平台 + 账单项目 + 业务备注关键词 + 商品名称关键词。
     *
     * 业务备注/商品名称是「区分条件」：同一个账单项目在业务上不同时，靠它们区分；
     * 条件完全相同的两条规则才是真重复。
     */
    public function keyOf(array $rule): string
    {
        return implode('|', [
            trim((string) ($rule['platform'] ?? '')),
            trim((string) ($rule['item'] ?? '')),
            trim((string) ($rule['memo'] ?? '')),
            trim((string) ($rule['goods'] ?? '')),
        ]);
    }

    /** @return array<string,mixed> */
    public function options(): array
    {
        $rules = $this->all();
        $collect = static function (string $field) use ($rules): array {
            $seen = [];
            foreach ($rules as $rule) {
                $value = trim((string) ($rule[$field] ?? ''));
                if ($value !== '') {
                    $seen[$value] = true;
                }
            }
            $values = array_keys($seen);
            sort($values);

            return $values;
        };

        return [
            'platforms' => $collect('platform'),
            'categories' => array_keys(self::CATEGORY_BASIS),
            'basis' => self::BASISES,
            'invoices' => self::INVOICES,
        ];
    }

    /** @return array<int,array<string,mixed>> 最近的操作记录（倒序） */
    public function events(int $limit = 50): array
    {
        $payload = $this->read($this->eventPath());
        $events = is_array($payload['events'] ?? null) ? $payload['events'] : [];

        return array_slice(array_reverse($events), 0, $limit);
    }

    /**
     * 本模块统一用的“现在”：固定按平台时区，不受页面请求里公司设置覆盖的影响。
     *
     * 直接用 now() 的话，页面操作写进日志的时间会差 7 小时（Europe/London）。
     */
    public function platformNow(): Carbon
    {
        $timezone = trim((string) config('app.platform_timezone', ''));

        if ($timezone === '') {
            $timezone = (string) config('app.timezone', 'UTC');
        }

        try {
            return Carbon::now($timezone);
        } catch (\Throwable) {
            return Carbon::now(config('app.timezone', 'UTC'));
        }
    }

    private function isEmptyRow(array $values): bool
    {
        return trim((string) ($values['platform'] ?? '')) === ''
            && trim((string) ($values['item'] ?? '')) === '';
    }

    private function ensureSeeded(): void
    {
        if (File::exists($this->path())) {
            return;
        }

        $this->persist($this->seed());
    }

    /** @param array<int,array<string,mixed>> $rules */
    private function persist(array $rules): void
    {
        if (! File::isDirectory($this->dir()) && ! File::makeDirectory($this->dir(), 0775, true) && ! File::isDirectory($this->dir())) {
            throw new RuntimeException('无法创建映射表存储目录。');
        }

        $json = json_encode(
            ['updated_at' => $this->platformNow()->toDateTimeString(), 'rules' => array_values($rules)],
            JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT
        );

        if ($json === false) {
            throw new RuntimeException('映射表序列化失败。');
        }

        File::put($this->path(), $json, true);
    }

    private function logEvent(string $action, ?int $id, ?array $before, ?array $after, ?int $userId, array $extra = []): void
    {
        $payload = $this->read($this->eventPath());
        $events = is_array($payload['events'] ?? null) ? $payload['events'] : [];

        $events[] = array_merge([
            'at' => $this->platformNow()->toDateTimeString(),
            'action' => $action,
            'id' => $id,
            'before' => $before,
            'after' => $after,
            'user_id' => $userId,
        ], $extra);

        if (count($events) > 500) {
            $events = array_slice($events, -500);
        }

        File::put($this->eventPath(), (string) json_encode(['events' => $events], JSON_UNESCAPED_UNICODE), true);
    }

    /** @return array<string,mixed> */
    private function read(string $path): array
    {
        if (! File::exists($path)) {
            return [];
        }

        $payload = json_decode((string) File::get($path), true);

        return is_array($payload) ? $payload : [];
    }
}