<?php

namespace Modules\EcommerceFinance\Services;

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

class FinanceLedgerFlowSummaryEditor
{
    private const MAX_COLUMNS = 30;

    private readonly ConnectionInterface $connection;

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

    /**
     * @param list<string> $fieldNames
     * @return list<array<string,mixed>>
     */
    public function createColumns(
        array $fieldNames,
        ?int $anchorFieldId = null,
        string $position = 'end',
    ): array {
        $position = in_array($position, ['left', 'right'], true) ? $position : 'end';
        $fieldNames = array_values(array_map(function (mixed $value): string {
            $text = trim((string) $value);

            return preg_replace('/\s+/u', ' ', $text) ?? $text;
        }, $fieldNames));
        if ($fieldNames === [] || count($fieldNames) > 20) {
            throw ValidationException::withMessages([
                'field_names' => '一次可新增 1 至 20 个自定义列。',
            ]);
        }
        foreach ($fieldNames as $index => $fieldName) {
            if ($fieldName === '') {
                throw ValidationException::withMessages([
                    'field_names.' . $index => '请填写列名。',
                ]);
            }
            if (mb_strlen($fieldName) > 50) {
                throw ValidationException::withMessages([
                    'field_names.' . $index => '列名不能超过 50 个字符。',
                ]);
            }
        }

        $normalizedNames = array_map(static fn (string $name): string => mb_strtolower($name), $fieldNames);
        if (count(array_unique($normalizedNames)) !== count($normalizedNames)) {
            throw ValidationException::withMessages([
                'field_names' => '一次新增的列名不能重复。',
            ]);
        }

        return $this->connection->transaction(function () use (
            $fieldNames,
            $normalizedNames,
            $anchorFieldId,
            $position,
        ): array {
            $existingFields = $this->connection->table('fin_flow_summary_custom_fields')
                ->orderBy('sort_order')
                ->orderBy('id')
                ->lockForUpdate()
                ->get();
            if ($existingFields->count() + count($fieldNames) > self::MAX_COLUMNS) {
                throw ValidationException::withMessages([
                    'field_names' => '账户资金汇总最多可设置 ' . self::MAX_COLUMNS . ' 个自定义列。',
                ]);
            }

            $existingNames = $existingFields
                ->pluck('field_name')
                ->map(static fn (mixed $name): string => mb_strtolower(trim((string) $name)))
                ->all();
            if (array_intersect($normalizedNames, $existingNames) !== []) {
                throw ValidationException::withMessages([
                    'field_names' => '账户资金汇总已存在同名列。',
                ]);
            }

            $anchor = null;
            if ($anchorFieldId !== null) {
                $anchor = $existingFields->firstWhere('id', $anchorFieldId);
                if ($anchor === null) {
                    throw ValidationException::withMessages([
                        'anchor_field_id' => '插入位置已变更，请刷新页面后重试。',
                    ]);
                }
            }

            $insertIndex = $existingFields->count();
            if ($anchor !== null) {
                $anchorIndex = $existingFields->search(
                    static fn (object $field): bool => (int) $field->id === $anchorFieldId,
                );
                $insertIndex = $position === 'left' ? (int) $anchorIndex : (int) $anchorIndex + 1;
            }

            $now = now();
            $ordered = $existingFields->values()->all();
            $placeholders = array_map(
                static fn (string $name): array => ['new_name' => $name],
                $fieldNames,
            );
            array_splice($ordered, $insertIndex, 0, $placeholders);
            $created = [];
            foreach ($ordered as $index => $field) {
                $sortOrder = ($index + 1) * 10;
                if (is_array($field) && isset($field['new_name'])) {
                    $values = [
                        'field_key' => (string) Str::uuid(),
                        'field_name' => (string) $field['new_name'],
                        'sort_order' => $sortOrder,
                        'created_by' => (string) (user()?->name ?? ''),
                        'updated_by' => (string) (user()?->name ?? ''),
                        'created_at' => $now,
                        'updated_at' => $now,
                    ];
                    $id = (int) $this->connection->table('fin_flow_summary_custom_fields')
                        ->insertGetId($values);
                    $created[] = ['id' => $id] + $values;
                    continue;
                }

                if ((int) $field->sort_order !== $sortOrder) {
                    $this->connection->table('fin_flow_summary_custom_fields')
                        ->where('id', (int) $field->id)
                        ->update([
                            'sort_order' => $sortOrder,
                            'updated_by' => (string) (user()?->name ?? ''),
                            'updated_at' => $now,
                        ]);
                }
            }
            $this->audit(
                'flow_summary_col_add',
                (string) Str::uuid(),
                [
                    'position' => $position,
                    'anchor_field_id' => $anchorFieldId,
                    'after' => $created,
                ],
            );

            return $created;
        });
    }

    /**
     * @return array<string,mixed>
     */
    public function deleteColumn(int $id): array
    {
        return $this->connection->transaction(function () use ($id): array {
            $field = $this->connection->table('fin_flow_summary_custom_fields')
                ->where('id', $id)
                ->lockForUpdate()
                ->first();
            if ($field === null) {
                throw new NotFoundHttpException('未找到可删除的账户资金汇总自定义列。');
            }

            $this->connection->table('fin_flow_summary_custom_values')
                ->where('custom_field_id', $id)
                ->delete();
            $this->connection->table('fin_flow_summary_custom_fields')->where('id', $id)->delete();
            $this->audit(
                'flow_summary_col_del',
                (string) $field->field_key,
                ['before' => (array) $field, 'after' => null],
            );

            return (array) $field;
        });
    }

    /**
     * @return array<string,mixed>
     */
    public function updateValue(int $fieldId, string $accountShort, mixed $value): array
    {
        $accountShort = preg_replace('/\s+/u', ' ', trim($accountShort)) ?? trim($accountShort);
        $text = trim((string) ($value ?? ''));
        $text = preg_replace('/\s+/u', ' ', $text) ?? $text;

        return $this->connection->transaction(function () use ($fieldId, $accountShort, $text): array {
            $field = $this->connection->table('fin_flow_summary_custom_fields')
                ->where('id', $fieldId)
                ->lockForUpdate()
                ->first();
            if ($field === null) {
                throw new NotFoundHttpException('自定义列已删除，请刷新页面后重试。');
            }
            if ($accountShort === '' || FinanceLedgerIndependentAccounts::contains($accountShort)) {
                throw ValidationException::withMessages([
                    'account_short' => '请选择账户资金汇总中的账户。',
                ]);
            }
            if (! $this->connection->table('fin_accounts')->where('account_short', $accountShort)->exists()) {
                throw ValidationException::withMessages([
                    'account_short' => '账户简称不存在，请刷新页面后重试。',
                ]);
            }

            $query = $this->connection->table('fin_flow_summary_custom_values')
                ->where('custom_field_id', $fieldId)
                ->where('account_short', $accountShort);
            $existing = $query->first();
            $before = $existing?->value;
            $nextValue = $text !== '' ? mb_substr($text, 0, 4000) : null;
            if ($nextValue === null) {
                if ($existing !== null) {
                    $query->delete();
                }
            } elseif ($existing === null) {
                $this->connection->table('fin_flow_summary_custom_values')->insert([
                    'custom_field_id' => $fieldId,
                    'account_short' => $accountShort,
                    'value' => $nextValue,
                    'created_at' => now(),
                    'updated_at' => now(),
                ]);
            } else {
                $this->connection->table('fin_flow_summary_custom_values')
                    ->where('id', $existing->id)
                    ->update([
                        'value' => $nextValue,
                        'updated_at' => now(),
                    ]);
            }
            $this->audit(
                'flow_summary_val_set',
                (string) $field->field_key . '|' . $accountShort,
                [
                    'before' => $before,
                    'after' => $nextValue,
                ],
            );

            return [
                'field_id' => $fieldId,
                'field_key' => (string) $field->field_key,
                'account_short' => $accountShort,
                'value' => $nextValue,
            ];
        });
    }

    /**
     * @param array<string,mixed> $changes
     */
    private function audit(string $entityType, string $entityKey, array $changes): void
    {
        $this->connection->table('fin_ledger_edit_events')->insert([
            'entity_type' => $entityType,
            'entity_key' => mb_substr('flow_summary|' . $entityKey, 0, 200),
            'changes' => json_encode($changes, JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR),
            'user_id' => user()?->id,
            'user_name' => (string) (user()?->name ?? ''),
            'created_at' => now(),
        ]);
    }
}