<?php

namespace Modules\EcommerceFinance\Services;

use Illuminate\Database\ConnectionInterface;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;
use Illuminate\Support\Str;
use RuntimeException;
use Throwable;

/**
 * 将钉钉应付申请流程的固定流程编码同步为按流程聚合的共享镜像。
 *
 * 钉钉表单字段存放在 JSON 中，且历史版本字段不完全一致；镜像保留原始
 * 主表、表单和审批任务 payload，页面只在镜像库中解析和筛选。
 */
class DingPayableWorkflowMirrorSynchronizer
{
    private readonly ConnectionInterface $connection;

    public function __construct(private readonly UpstreamReadOnlyQueryFactory $queries)
    {
        $this->connection = app('db')->connection(
            (string) config('upstream_mirrors.connection', 'business_mirror')
        );
    }

    /** @return array{status:string,mode:string,batches:int,rows:int,dataset:string} */
    public function sync(bool $full = false, ?int $batchSize = null, ?int $maxBatches = null): array
    {
        $config = (array) config('upstream_mirrors.ding_payable_workflows', []);
        $dataset = (string) ($config['dataset_key'] ?? 'operations_replica.rpt.ding_payable_workflows');
        $target = (string) ($config['target_table'] ?? 'ding_payable_workflow_mirror');
        $source = (string) ($config['source_key'] ?? 'operations_replica');
        $processCode = (string) ($config['process_code'] ?? '');

        if ($processCode === '') {
            throw new RuntimeException('ding_payable_workflow_mirror_not_initialized');
        }

        $this->ensureMirrorTable($target);

        UpstreamOdbcConnection::reset($source);
        $state = $this->state($dataset);

        if (! $full && ($state['initial_completed_at'] ?? null) === null) {
            return ['status' => 'requires_full_sync', 'mode' => 'incremental', 'batches' => 0, 'rows' => 0, 'dataset' => $dataset];
        }

        $mode = $full ? 'full' : 'incremental';
        $resume = is_array($state)
            && ($state['run_mode'] ?? null) === $mode
            && in_array($state['status'] ?? null, ['running', 'failed'], true)
            && is_string($state['generation'] ?? null)
            && is_array($state['cursor'] ?? null);
        $generation = $resume ? (string) $state['generation'] : (string) Str::uuid();
        $cursor = $resume
            ? (string) ($state['cursor']['processInstanceId'] ?? '')
            : (string) ($this->decodeJson($state['high_watermark'] ?? null)['processInstanceId'] ?? '');
        $rows = $resume ? (int) ($state['last_upserted_rows'] ?? 0) : 0;
        $batchSize = min(max($batchSize ?? (int) ($config['batch_size'] ?? 100), 1), 500);
        $maxBatches = max($maxBatches ?? (int) ($config['max_batches_per_run'] ?? 2), 0);

        $this->start($dataset, $target, $source, $mode, $generation, $cursor, $resume);
        $batches = 0;

        try {
            while (true) {
                $workflows = $this->readWorkflows($source, $processCode, $cursor, $batchSize);
                if ($workflows === []) {
                    $this->complete($dataset, $target, $mode, $generation, $rows, $cursor);

                    return ['status' => 'succeeded', 'mode' => $mode, 'batches' => $batches, 'rows' => $rows, 'dataset' => $dataset];
                }

                $ids = array_values(array_filter(array_map(
                    static fn (array $row): string => (string) ($row['processInstanceId'] ?? ''),
                    $workflows,
                )));
                $schemes = $this->readRelated($source, 'ding_WorkflowScheme', ['id', 'processInstanceId', 'componentType', 'name', 'value', 'extValue'], $ids, 'id');
                $tasks = $this->readRelated($source, 'ding_WorkflowTask', ['processInstanceId', 'result', 'activityId', 'finishTime', 'createTime', 'userId', 'taskId', 'status', 'id'], $ids, 'id');

                $schemeById = $this->groupBy($schemes, 'processInstanceId');
                $taskById = $this->groupBy($tasks, 'processInstanceId');
                $now = now();
                $payloads = [];

                foreach ($workflows as $workflow) {
                    $id = (string) ($workflow['processInstanceId'] ?? '');
                    if ($id === '') {
                        continue;
                    }
                    $payloads[] = [
                        'process_instance_id' => $id,
                        'workflow_payload' => json_encode($workflow, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR),
                        'scheme_payload' => json_encode($schemeById[$id] ?? [], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR),
                        'task_payload' => json_encode($taskById[$id] ?? [], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR),
                        'workflow_created_at' => isset($workflow['createAt']) ? (string) $workflow['createAt'] : null,
                        'sync_generation' => $generation,
                        'synced_at' => $now,
                    ];
                }

                $cursor = (string) ($workflows[array_key_last($workflows)]['processInstanceId'] ?? $cursor);
                $rows += count($payloads);
                $batches++;
                $this->connection->transaction(function () use ($dataset, $target, $payloads, $cursor, $generation, $rows, $now): void {
                    if ($payloads !== []) {
                        $this->connection->table($target)->upsert(
                            $payloads,
                            ['process_instance_id'],
                            ['workflow_payload', 'scheme_payload', 'task_payload', 'workflow_created_at', 'sync_generation', 'synced_at'],
                        );
                    }
                    $this->connection->table('business_mirror_table_states')
                        ->where('dataset_key', $dataset)
                        ->update([
                            'cursor' => json_encode(['processInstanceId' => $cursor], JSON_UNESCAPED_UNICODE),
                            'last_upserted_rows' => $rows,
                            'updated_at' => $now,
                        ]);
                });

                if (count($workflows) < $batchSize) {
                    $this->complete($dataset, $target, $mode, $generation, $rows, $cursor);

                    return ['status' => 'succeeded', 'mode' => $mode, 'batches' => $batches, 'rows' => $rows, 'dataset' => $dataset];
                }

                if ($maxBatches > 0 && $batches >= $maxBatches) {
                    return ['status' => 'running', 'mode' => $mode, 'batches' => $batches, 'rows' => $rows, 'dataset' => $dataset];
                }
            }
        } catch (Throwable $exception) {
            $this->connection->table('business_mirror_table_states')
                ->where('dataset_key', $dataset)
                ->update(['status' => 'failed', 'last_error_code' => mb_substr($exception::class, 0, 120), 'updated_at' => now()]);
            throw $exception;
        }
    }

    private function ensureMirrorTable(string $target): void
    {
        $schema = Schema::connection($this->connection->getName());
        if ($schema->hasTable($target)) {
            return;
        }
        $schema->create($target, function (Blueprint $table): void {
            $table->string('process_instance_id', 100)->primary();
            $table->json('workflow_payload');
            $table->json('scheme_payload');
            $table->json('task_payload')->nullable();
            $table->string('workflow_created_at', 32)->nullable()->index();
            $table->uuid('sync_generation')->nullable()->index();
            $table->dateTime('synced_at', 6);
        });
    }

    /** @return array<string,mixed>|null */
    private function state(string $dataset): ?array
    {
        $row = $this->connection->table('business_mirror_table_states')->where('dataset_key', $dataset)->first();
        if ($row === null) {
            return null;
        }
        $state = (array) $row;
        $state['cursor'] = is_string($state['cursor'] ?? null) ? (json_decode($state['cursor'], true) ?: []) : ($state['cursor'] ?? []);

        return $state;
    }

    private function start(string $dataset, string $target, string $source, string $mode, string $generation, string $cursor, bool $resume): void
    {
        $now = now();
        $values = [
            'source_key' => $source,
            'source_object' => 'rpt.ding_Workflow + rpt.ding_WorkflowScheme + rpt.ding_WorkflowTask',
            'target_table' => $target,
            'status' => 'running',
            'run_mode' => $mode,
            'generation' => $generation,
            'last_attempted_at' => $now,
            'last_error_code' => null,
            'updated_at' => $now,
        ];
        if (! $resume) {
            $values += ['cursor' => null, 'window_started_at' => null, 'window_ends_at' => null, 'last_upserted_rows' => 0];
        }
        $query = $this->connection->table('business_mirror_table_states')->where('dataset_key', $dataset);
        $query->exists()
            ? $query->update($values)
            : $this->connection->table('business_mirror_table_states')->insert(['dataset_key' => $dataset, 'created_at' => $now] + $values);
    }

    private function complete(string $dataset, string $target, string $mode, string $generation, int $rows, string $cursor): void
    {
        $now = now();
        $this->connection->transaction(function () use ($dataset, $target, $mode, $generation, $rows, $cursor, $now): void {
            if ($mode === 'full') {
                $this->connection->table($target)->where(function ($query) use ($generation): void {
                    $query->whereNull('sync_generation')->orWhere('sync_generation', '!=', $generation);
                })->delete();
            }
            $values = [
                'status' => 'succeeded',
                'cursor' => null,
                'high_watermark' => json_encode(['processInstanceId' => $cursor], JSON_UNESCAPED_UNICODE),
                'last_succeeded_at' => $now,
                'last_upserted_rows' => $rows,
                'mirror_row_count' => $this->connection->table($target)->count(),
                'last_error_code' => null,
                'updated_at' => $now,
            ];
            if ($mode === 'full') {
                $values['initial_completed_at'] = $now;
                $values['last_full_succeeded_at'] = $now;
            }
            $this->connection->table('business_mirror_table_states')->where('dataset_key', $dataset)->update($values);
        });
    }

    /** @return array<string,mixed> */
    private function decodeJson(mixed $value): array
    {
        if (is_array($value)) {
            return $value;
        }
        if (! is_string($value) || $value === '') {
            return [];
        }
        $decoded = json_decode($value, true);
        return is_array($decoded) ? $decoded : [];
    }

    /** @return list<array<string,mixed>> */
    private function readWorkflows(string $source, string $processCode, string $cursor, int $limit): array
    {
        $where = '[processCode] = ?';
        $bindings = [$processCode];
        if ($cursor !== '') {
            $where .= ' AND [processInstanceId] > ?';
            $bindings[] = $cursor;
        }
        return $this->queries->forSource($source)->select(
            'SELECT TOP (' . $limit . ') [finishTime],[businessId],[title],[result],[originatorUserId],[originatorDeptId],[originatorDeptName],[status],[bizAction],[processInstanceId],[joinAt],[updateAt],[createAt],[processCode],[flowType] FROM [rpt].[ding_Workflow] WHERE ' . $where . ' ORDER BY [processInstanceId]',
            $bindings,
        );
    }

    /** @param list<string> $ids @param list<string> $columns @return list<array<string,mixed>> */
    private function readRelated(string $source, string $table, array $columns, array $ids, string $order): array
    {
        if ($ids === []) {
            return [];
        }
        $placeholders = implode(',', array_fill(0, count($ids), '?'));
        return $this->queries->forSource($source)->select(
            'SELECT ' . implode(', ', array_map(static fn (string $column): string => '[' . $column . ']', $columns))
                . ' FROM [rpt].[' . $table . '] WHERE [processInstanceId] IN (' . $placeholders . ') ORDER BY [' . $order . ']',
            $ids,
        );
    }

    /** @param list<array<string,mixed>> $rows @return array<string,list<array<string,mixed>>> */
    private function groupBy(array $rows, string $column): array
    {
        $grouped = [];
        foreach ($rows as $row) {
            $key = (string) ($row[$column] ?? '');
            if ($key !== '') {
                $grouped[$key][] = $row;
            }
        }
        return $grouped;
    }
}