<?php

namespace Modules\EcommerceFinance\Services;

use App\Utilities\FinanceLedgerIndependentAccounts;
use Carbon\CarbonImmutable;
use Illuminate\Database\ConnectionInterface;
use Illuminate\Database\DatabaseManager;
use Illuminate\Support\Str;
use Illuminate\Validation\ValidationException;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;

class FinanceLedgerIndependentTransactionEditor
{
    private readonly ConnectionInterface $connection;

    public function __construct(DatabaseManager $databases)
    {
        $this->connection = $databases->connection(
            (string) config('upstream_mirrors.connection', 'business_mirror'),
        );
    }

    /**
     * @param array<string,mixed> $data
     * @return array<string,mixed>
     */
    public function update(int $id, array $data): array
    {
        $date = $this->date($data['txn_date'] ?? null);
        $incomeCents = $this->cents($data['income'] ?? 0);
        $expenseCents = $this->cents($data['expense'] ?? 0);
        if (($incomeCents > 0) === ($expenseCents > 0)) {
            throw ValidationException::withMessages([
                'income' => '收入和支出只能填写一项。',
            ]);
        }

        return $this->connection->transaction(function () use (
            $id,
            $date,
            $incomeCents,
            $expenseCents,
            $data,
        ): array {
            $before = $this->activeRow($id, true);
            $accountShort = (string) $before->account_short;
            $customFields = $this->customFields($accountShort);
            $customBefore = $this->customValues($id, $customFields);
            $customAfter = $this->submittedCustomValues(
                $data['custom_values'] ?? null,
                $customFields,
                $customBefore,
            );

            $now = now();
            $income = $incomeCents / 100;
            $expense = $expenseCents / 100;
            $values = [
                'txn_date' => $date,
                'counterparty_info' => $this->nullableText($data['counterparty_info'] ?? null, 255),
                'detail' => $this->nullableText($data['detail'] ?? null, 4000),
                'income' => $income,
                'expense' => $expense,
                'balance' => $this->nullableMoney($data['balance'] ?? null),
                'approval_no' => $this->nullableText($data['approval_no'] ?? null, 100),
                'payment_remark' => $this->nullableText($data['payment_remark'] ?? null, 500),
                'source' => trim((string) ($data['source'] ?? $before->source)),
                'updated_by' => (string) (user()?->name ?? ''),
                'updated_at' => $now,
            ];
            $this->connection->table('fin_transactions')->where('id', $id)->update($values);

            foreach ($customFields as $fieldKey => $field) {
                $value = $customAfter[$fieldKey] ?? null;
                if ($value === null) {
                    $this->connection->table('fin_transaction_custom_values')
                        ->where('custom_field_id', (int) $field['id'])
                        ->where('transaction_id', $id)
                        ->delete();
                    continue;
                }
                $this->connection->table('fin_transaction_custom_values')->updateOrInsert(
                    [
                        'custom_field_id' => (int) $field['id'],
                        'transaction_id' => $id,
                    ],
                    [
                        'value' => $value,
                        'created_at' => $now,
                        'updated_at' => $now,
                    ],
                );
            }

            $after = [
                'id' => $id,
                'txn_date' => $date,
                'account_short' => $accountShort,
                'counterparty_info' => $values['counterparty_info'],
                'detail' => $values['detail'],
                'income' => $income,
                'expense' => $expense,
                'balance' => $values['balance'],
                'approval_no' => $values['approval_no'],
                'payment_remark' => $values['payment_remark'],
                'source' => $values['source'],
                'custom_values' => $customAfter,
            ];
            $this->audit(
                'stmt_txn_update',
                (string) $before->row_key,
                [
                    'before' => $this->rowSnapshot($before, $customBefore),
                    'after' => $after,
                ],
            );

            return $after;
        });
    }

    /**
     * @return array<string,mixed>
     */
    public function delete(int $id): array
    {
        return $this->connection->transaction(function () use ($id): array {
            $before = $this->activeRow($id, true);
            $customFields = $this->customFields((string) $before->account_short);
            $customValues = $this->customValues($id, $customFields);
            $now = now();

            $this->connection->table('fin_transactions')->where('id', $id)->update([
                'deleted_at' => $now,
                'updated_by' => (string) (user()?->name ?? ''),
                'updated_at' => $now,
            ]);
            $this->audit(
                'stmt_txn_delete',
                (string) $before->row_key,
                [
                    'before' => $this->rowSnapshot($before, $customValues),
                    'after' => null,
                ],
            );

            return $this->rowSnapshot($before, $customValues);
        });
    }

    /**
     * @return list<array{id:int,display_order:float}>
     */
    public function insertAround(int $id, string $position, int $count): array
    {
        if (! in_array($position, ['above', 'below'], true) || $count < 1 || $count > 20) {
            throw ValidationException::withMessages([
                'position' => '请选择在上方或下方插入 1 至 20 行。',
            ]);
        }

        return $this->connection->transaction(function () use ($id, $position, $count): array {
            $anchor = $this->activeRow($id, true);
            $rows = $this->connection->table('fin_transactions')
                ->where('account_short', (string) $anchor->account_short)
                ->whereDate('txn_date', (string) $anchor->txn_date)
                ->whereNull('deleted_at')
                ->orderByRaw('COALESCE(display_order, id) DESC')
                ->orderByDesc('id')
                ->lockForUpdate()
                ->get(['id', 'display_order']);
            $anchorIndex = $rows->search(
                static fn (object $row): bool => (int) $row->id === $id,
            );
            if ($anchorIndex === false) {
                throw new NotFoundHttpException('未找到要插入位置的独立账单明细。');
            }
            $orders = $this->insertOrders($rows->values()->all(), (int) $anchorIndex, $position, $count);
            $now = now();
            $created = [];
            foreach ($orders as $displayOrder) {
                $rowKey = hash('sha256', 'independent-insert:' . (string) Str::uuid());
                $insertedId = (int) $this->connection->table('fin_transactions')->insertGetId([
                    'txn_date' => substr((string) $anchor->txn_date, 0, 10),
                    'account_short' => (string) $anchor->account_short,
                    'counterparty_info' => null,
                    'detail' => null,
                    'income' => 0,
                    'expense' => 0,
                    'balance' => null,
                    'approval_no' => null,
                    'payment_remark' => null,
                    'source' => FinanceLedgerTransactionWriter::MANUAL_SOURCE,
                    'source_value' => null,
                    'process_type' => '手工插入',
                    'row_key' => $rowKey,
                    'display_order' => $displayOrder,
                    'synced_at' => $now,
                    'created_at' => $now,
                    'updated_at' => $now,
                    'created_by' => (string) (user()?->name ?? ''),
                    'updated_by' => (string) (user()?->name ?? ''),
                ]);
                $created[] = [
                    'id' => $insertedId,
                    'display_order' => $displayOrder,
                ];
            }
            $this->audit(
                'stmt_txn_insert',
                (string) $anchor->row_key,
                [
                    'anchor_id' => $id,
                    'position' => $position,
                    'count' => $count,
                    'after' => $created,
                ],
            );

            return $created;
        });
    }

    /**
     * @param list<object> $rows
     * @return list<float>
     */
    private function insertOrders(array $rows, int $anchorIndex, string $position, int $count): array
    {
        $anchorOrder = $this->displayOrder($rows[$anchorIndex]);
        $orders = [];
        if ($position === 'above') {
            $upperOrder = $anchorIndex > 0 ? $this->displayOrder($rows[$anchorIndex - 1]) : null;
            for ($index = 1; $index <= $count; $index++) {
                $orders[] = $upperOrder === null || $upperOrder <= $anchorOrder
                    ? $anchorOrder + $index
                    : round($anchorOrder + (($upperOrder - $anchorOrder) * $index / ($count + 1)), 10);
            }

            return $orders;
        }

        $lowerOrder = $anchorIndex + 1 < count($rows)
            ? $this->displayOrder($rows[$anchorIndex + 1])
            : null;
        for ($index = 1; $index <= $count; $index++) {
            $orders[] = $lowerOrder === null || $lowerOrder >= $anchorOrder
                ? $anchorOrder - $index
                : round($lowerOrder + (($anchorOrder - $lowerOrder) * $index / ($count + 1)), 10);
        }

        return $orders;
    }

    private function displayOrder(object $row): float
    {
        return $row->display_order === null ? (float) $row->id : (float) $row->display_order;
    }

    private function activeRow(int $id, bool $lock = false): object
    {
        $query = $this->connection->table('fin_transactions')
            ->where('id', $id)
            ->whereIn('account_short', FinanceLedgerIndependentAccounts::names())
            ->whereNull('deleted_at');
        if ($lock) {
            $query->lockForUpdate();
        }
        $row = $query->first();
        if ($row === null) {
            throw new NotFoundHttpException('未找到可编辑的独立账单明细。');
        }

        return $row;
    }

    /**
     * @return array<string,array{id:int,field_key:string,field_name:string}>
     */
    private function customFields(string $accountShort): array
    {
        return $this->connection->table('fin_transaction_custom_fields')
            ->where('account_short', $accountShort)
            ->orderBy('sort_order')
            ->orderBy('id')
            ->get(['id', 'field_key', 'field_name'])
            ->mapWithKeys(static fn (object $field): array => [
                (string) $field->field_key => [
                    'id' => (int) $field->id,
                    'field_key' => (string) $field->field_key,
                    'field_name' => (string) $field->field_name,
                ],
            ])
            ->all();
    }

    /**
     * @param array<string,array{id:int,field_key:string,field_name:string}> $fields
     * @return array<string,?string>
     */
    private function customValues(int $transactionId, array $fields): array
    {
        if ($fields === []) {
            return [];
        }

        $values = $this->connection->table('fin_transaction_custom_values')
            ->where('transaction_id', $transactionId)
            ->whereIn('custom_field_id', array_column($fields, 'id'))
            ->pluck('value', 'custom_field_id');
        $result = [];
        foreach ($fields as $fieldKey => $field) {
            $value = $values->get((int) $field['id']);
            $result[$fieldKey] = $value === null ? null : (string) $value;
        }

        return $result;
    }

    /**
     * @param array<string,array{id:int,field_key:string,field_name:string}> $fields
     * @param array<string,?string> $existing
     * @return array<string,?string>
     */
    private function submittedCustomValues(mixed $submitted, array $fields, array $existing): array
    {
        if ($submitted === null) {
            return $existing;
        }
        if (! is_array($submitted)) {
            throw ValidationException::withMessages([
                'custom_values' => '自定义列数据格式不正确。',
            ]);
        }
        $unknown = array_diff(array_keys($submitted), array_keys($fields));
        if ($unknown !== []) {
            throw ValidationException::withMessages([
                'custom_values' => '自定义列已变更，请刷新页面后重新编辑。',
            ]);
        }

        $values = [];
        foreach ($fields as $fieldKey => $field) {
            $values[$fieldKey] = $this->nullableText($submitted[$fieldKey] ?? null, 4000);
        }

        return $values;
    }

    /**
     * @return array<string,mixed>
     */
    private function rowSnapshot(object $row, array $customValues): array
    {
        return [
            'id' => (int) $row->id,
            'row_key' => (string) $row->row_key,
            'txn_date' => substr((string) $row->txn_date, 0, 10),
            'account_short' => (string) $row->account_short,
            'counterparty_info' => $row->counterparty_info !== null ? (string) $row->counterparty_info : null,
            'detail' => $row->detail !== null ? (string) $row->detail : null,
            'income' => round((float) $row->income, 2),
            'expense' => round((float) $row->expense, 2),
            'balance' => $row->balance !== null ? round((float) $row->balance, 2) : null,
            'approval_no' => $row->approval_no !== null ? (string) $row->approval_no : null,
            'payment_remark' => $row->payment_remark !== null ? (string) $row->payment_remark : null,
            'source' => (string) $row->source,
            'custom_values' => $customValues,
        ];
    }

    /**
     * @param array<string,mixed> $changes
     */
    private function audit(string $entityType, string $rowKey, array $changes): void
    {
        $this->connection->table('fin_ledger_edit_events')->insert([
            'entity_type' => $entityType,
            'entity_key' => 'independent_transaction|' . $rowKey,
            'changes' => json_encode($changes, JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR),
            'user_id' => user()?->id,
            'user_name' => (string) (user()?->name ?? ''),
            'created_at' => now(),
        ]);
    }

    private function date(mixed $value): string
    {
        $text = trim((string) $value);
        $date = CarbonImmutable::createFromFormat('!Y-m-d', $text);
        if (! $date instanceof CarbonImmutable || $date->format('Y-m-d') !== $text) {
            throw ValidationException::withMessages([
                'txn_date' => '动账日期必须使用 YYYY-MM-DD 格式。',
            ]);
        }

        return $text;
    }

    private function cents(mixed $value): int
    {
        return (int) round((float) $value * 100);
    }

    private function nullableMoney(mixed $value): ?float
    {
        $text = trim((string) ($value ?? ''));

        return $text === '' ? null : round((float) $text, 2);
    }

    private function nullableText(mixed $value, int $length): ?string
    {
        $text = trim((string) ($value ?? ''));
        if ($text === '') {
            return null;
        }
        $text = preg_replace('/\s+/u', ' ', $text) ?? $text;
        if (mb_strlen($text) > $length) {
            throw ValidationException::withMessages([
                'detail' => '字段内容超过允许长度。',
            ]);
        }

        return $text;
    }
}