import type { Bindings, ExecutionGraph } from '../types';
import { ExecutionError, WorkflowPaused } from '../types';
import { GraphExecutor } from '../graph-executor';
import { graphSchema } from '../lib/schemas';
import { createComponentLoader } from '../lib/component-loader';
import { writeEvaluation, updateComponentStats } from './execution-evaluator';
import { parseTriplets } from './triplet-parser';
import { searchNodes } from './search-nodes';
import { buildExecutionGraph } from './graph-builder';

export async function handleCypherSearch(
  triplets: unknown[],
  env: Bindings,
): Promise<{ nodes: Record<string, unknown>; cypher: unknown; missing: string[] }> {
  const parsed = parseTriplets(triplets);
  if (!parsed) {
    throw new Error('無法解析任何節點');
  }

  const { nodeResults } = searchNodes(parsed);

  const graph = buildExecutionGraph(parsed, nodeResults, 'cypher-search-result', 'Cypher Search Result');
  return { nodes: nodeResults, cypher: { nodes: graph.nodes, edges: graph.edges }, missing: [] };
}

export async function handleCypherExecute(
  triplets: unknown[],
  context: Record<string, unknown> | undefined,
  graphId: string,
  graphName: string,
  config: Record<string, Record<string, unknown>> | undefined,
  env: Bindings,
  waitUntil: (promise: Promise<void>) => void,
  apiKey?: string,
): Promise<{
  success: boolean;
  data?: unknown;
  error?: string;
  trace?: unknown;
  duration_ms: number;
  graph?: ExecutionGraph;
  // resumable workflow: 節點 pending 時回 paused（不算 success 也不算 fail）
  paused?: boolean;
  task_id?: string;
  run_id?: string;
  paused_node_id?: string;
}> {
  const parsed = parseTriplets(triplets as unknown[]);
  if (!parsed) {
    throw new Error('無法解析任何節點');
  }

  const { nodeResults } = searchNodes(parsed, config);

  const graph = buildExecutionGraph(parsed, nodeResults, graphId, graphName, config);
  const parseResult = graphSchema.safeParse(graph);
  if (!parseResult.success) {
    throw new Error('圖定義產生失敗');
  }

  const loader = createComponentLoader(env);
  const executor = new GraphExecutor(loader, undefined, env, apiKey);
  const start = Date.now();

  try {
    const result = await executor.execute(parseResult.data as ExecutionGraph, context ?? {}, env.EXEC_CONTEXT);
    const duration_ms = Date.now() - start;

    // 非同步記錄統計（Phase 7 補充 analytics，目前為 no-op）
    const componentId = graph.nodes.find(n => n.componentId)?.componentId ?? graphId;
    const runId = `${graphId}-${Date.now()}`;
    waitUntil(writeEvaluation(env, {
      run_id: runId,
      workflow_id: graphId,
      component_id: componentId,
      verdict: 'success',
      duration_ms,
      evaluated_at: Date.now(),
    }));
    waitUntil(updateComponentStats(env, componentId, 'success', duration_ms));

    return { success: true, data: result.data, trace: result.trace, duration_ms, graph };
  } catch (err) {
    const duration_ms = Date.now() - start;

    // Resumable workflow: 節點回 pending → 回 paused 結構，不算成功也不算失敗
    // SDD: resumable-workflow/design.md
    if (err instanceof WorkflowPaused) {
      return {
        success: true,
        paused: true,
        task_id: err.task_id,
        run_id: err.run_id,
        paused_node_id: err.paused_node_id,
        trace: err.trace_so_far,
        duration_ms,
        graph,
      };
    }

    const errMsg = err instanceof Error ? err.message : String(err);
    const componentId = graph.nodes.find(n => n.componentId)?.componentId ?? graphId;
    const runId = `${graphId}-${Date.now()}`;
    waitUntil(writeEvaluation(env, {
      run_id: runId,
      workflow_id: graphId,
      component_id: componentId,
      verdict: 'failed',
      duration_ms,
      error_message: errMsg.slice(0, 200),
      evaluated_at: Date.now(),
    }));
    waitUntil(updateComponentStats(env, componentId, 'failed', duration_ms));
    if (err instanceof ExecutionError) {
      const traceFormatted = err.trace.map(s => ({
        node: s.nodeId,
        status: s.error ? 'failed' : 'success',
        ...(s.error ? { error: s.error } : {}),
      }));
      throw new Error(JSON.stringify({
        success: false,
        error: errMsg,
        failed_node: err.failed_node,
        failed_input: err.failed_input,
        trace: traceFormatted,
        duration_ms,
      }));
    }
    throw err;
  }
}
