import { addEdge, MarkerType } from '@xyflow/react';
import defaultWorkflowData from '../../workflows/rwb1_workflow.json';
import { paraphraseText } from './api.js';
import { normalizeComponentTemplates } from './componentLibrary.js';
import { createBrowserId } from './ids.js';
import {
  COMPONENT_INPUT_TYPE,
  COMPONENT_NODE_TYPE,
  COMPONENT_OUTPUT_TYPE,
  createComponentSubgraph,
  createNodeInstance,
  getNodeDefinition,
  getNodeHandles,
  hydrateNode,
  isComponentBoundaryType,
  isComponentNodeType,
  stripRuntimeFromNode,
} from './nodeRegistry.js';

export const FLOW_FORMAT = 'nodes-ui-flow';
export const FLOW_VERSION = 2;
export const AUTOSAVE_KEY = 'workflow_autosave_react_flow_v3';
export const LEGACY_AUTOSAVE_KEY = 'workflow_autosave';
export const DEFAULT_VIEWPORT = {
  x: 0,
  y: 0,
  zoom: 1,
};
export const DEFAULT_ASSISTANT_ROLE =
  'Ты компьютерный ИИ-ассистент. Отвечай кратко, естественно, одним живым абзацем, без Markdown, списков, заголовков и нумерации.';

function normalizeEdge(edge) {
  return {
    ...edge,
    id: String(edge.id),
    source: String(edge.source),
    target: String(edge.target),
    type: edge.type === 'smoothstep' ? 'default' : edge.type || 'default',
    markerEnd: edge.markerEnd || { type: MarkerType.ArrowClosed },
  };
}

function sanitizeViewport(viewport) {
  return viewport && typeof viewport === 'object' ? viewport : null;
}

export function hydrateGraph(graph) {
  return {
    nodes: (graph?.nodes || []).map((node) => hydrateNode(node)),
    edges: (graph?.edges || []).map((edge) => normalizeEdge(edge)),
    viewport: sanitizeViewport(graph?.viewport),
  };
}

function serializeGraph(graph) {
  return {
    nodes: (graph?.nodes || []).map((node) => stripRuntimeFromNode(node)),
    edges: (graph?.edges || []).map((edge) => ({
      id: edge.id,
      source: edge.source,
      sourceHandle: edge.sourceHandle || null,
      target: edge.target,
      targetHandle: edge.targetHandle || null,
      type: edge.type === 'smoothstep' ? 'default' : edge.type || 'default',
    })),
    viewport: sanitizeViewport(graph?.viewport),
  };
}

export function createWorkflowDocument(rootGraph, componentTemplates = [], settings = {}) {
  return {
    format: FLOW_FORMAT,
    version: FLOW_VERSION,
    rootGraph: hydrateGraph(rootGraph),
    componentTemplates: normalizeComponentTemplates(componentTemplates),
    settings: settings && typeof settings === 'object' ? settings : {},
  };
}

export function getGraphAtPath(document, path = []) {
  let graph = document.rootGraph;

  for (const nodeId of path) {
    const node = graph.nodes.find((candidate) => candidate.id === nodeId && isComponentNodeType(candidate.type));
    if (!node) {
      break;
    }

    graph = node.data.subgraph || createComponentSubgraph();
  }

  return graph;
}

export function updateGraphAtPath(document, path, updater) {
  function updateGraph(graph, remainingPath) {
    if (remainingPath.length === 0) {
      return hydrateGraph(updater(graph));
    }

    const [currentNodeId, ...rest] = remainingPath;

    return hydrateGraph({
      ...graph,
      nodes: graph.nodes.map((node) => {
        if (node.id !== currentNodeId || !isComponentNodeType(node.type)) {
          return node;
        }

        const nextSubgraph = updateGraph(node.data.subgraph || createComponentSubgraph(), rest);

        return hydrateNode({
          ...node,
          data: {
            ...node.data,
            subgraph: nextSubgraph,
          },
        });
      }),
    });
  }

  return {
    ...document,
    rootGraph: updateGraph(document.rootGraph, path),
  };
}

export function createBlankWorkflow() {
  const startNode = createNodeInstance('basic/start', { x: 40, y: 80 });
  const questionNode = createNodeInstance('basic/question', { x: 360, y: 80 });
  const dialogNode = createNodeInstance('basic/dialog', { x: 760, y: 80 });

  return createWorkflowDocument({
    nodes: [startNode, questionNode, dialogNode],
    edges: [
      {
        id: createBrowserId('edge'),
        source: startNode.id,
        sourceHandle: 'dialog',
        target: questionNode.id,
        targetHandle: 'dialog-in',
        type: 'default',
        markerEnd: { type: MarkerType.ArrowClosed },
      },
      {
        id: createBrowserId('edge'),
        source: questionNode.id,
        sourceHandle: 'dialog',
        target: dialogNode.id,
        targetHandle: 'dialog',
        type: 'default',
        markerEnd: { type: MarkerType.ArrowClosed },
      },
    ],
    viewport: null,
  });
}

export function createDefaultWorkflow() {
  return parseWorkflowData(defaultWorkflowData);
}

function convertLegacyNode(legacyNode) {
  const type = legacyNode.type;
  const data = {};

  if (type === 'basic/text') {
    data.text = legacyNode.properties?.text || '';
    data.width = legacyNode.size?.[0];
    data.height = legacyNode.size?.[1];
  }

  if (type === 'basic/classifier') {
    data.options = legacyNode.properties?.options || '';
    data.width = legacyNode.size?.[0];
  }

  if (type === 'basic/request' || type === 'basic/randomlist') {
    data.width = legacyNode.size?.[0];
  }

  if (type === 'basic/dialog') {
    data.width = legacyNode.size?.[0];
    data.height = legacyNode.size?.[1];
  }

  if (type === 'basic/script') {
    data.width = legacyNode.size?.[0];
    data.hasScriptOutput =
      Boolean(legacyNode.properties?.hasScriptOutput) ||
      Boolean((legacyNode.outputs || []).some((output) => output.name?.toLowerCase().includes('script')));

    data.entries = (legacyNode.inputs || [])
      .slice(1)
      .filter((input) => input?.name?.startsWith('user') || input?.name?.startsWith('character'))
      .map((input, index) => ({
        id: `${input.name?.startsWith('user') ? 'user' : 'character'}-${index}`,
        kind: input.name?.startsWith('user') ? 'user' : 'character',
      }));
  }

  if (type === 'basic/ifelse') {
    data.width = legacyNode.size?.[0];
    data.conditions = (legacyNode.properties?.conditions || [{ keyword: '' }]).map((condition, index) => ({
      id: `condition-${index}`,
      keyword: condition.keyword || '',
    }));
  }

  return hydrateNode({
    id: String(legacyNode.id),
    type,
    position: {
      x: legacyNode.pos?.[0] || 0,
      y: legacyNode.pos?.[1] || 0,
    },
    data,
  });
}

function convertLiteGraphWorkflow(data) {
  const supportedNodes = (data.nodes || []).filter((node) => getNodeDefinition(node.type));
  const convertedNodes = supportedNodes.map(convertLegacyNode);
  const nodeLookup = new Map(convertedNodes.map((node) => [String(node.id), node]));

  const edges = (data.links || [])
    .filter(Boolean)
    .map((link) => {
      const [legacyId, originId, originSlot, targetId, targetSlot] = link;
      const sourceNode = nodeLookup.get(String(originId));
      const targetNode = nodeLookup.get(String(targetId));

      if (!sourceNode || !targetNode) {
        return null;
      }

      const sourceHandles = getNodeHandles(sourceNode.type, sourceNode.data).outputs;
      const targetHandles = getNodeHandles(targetNode.type, targetNode.data).inputs;
      const sourceHandle = sourceHandles[originSlot]?.id || sourceHandles[0]?.id || null;
      const targetHandle = targetHandles[targetSlot]?.id || targetHandles[0]?.id || null;

      return normalizeEdge({
        id: String(legacyId),
        source: sourceNode.id,
        sourceHandle,
        target: targetNode.id,
        targetHandle,
      });
    })
    .filter(Boolean);

  return {
    nodes: convertedNodes,
    edges,
    viewport: null,
  };
}

export function parseWorkflowData(data) {
  if (!data || typeof data !== 'object') {
    throw new Error('Invalid workflow file.');
  }

  if (data.format === FLOW_FORMAT && data.rootGraph) {
    return createWorkflowDocument(data.rootGraph, data.componentTemplates || [], data.settings || {});
  }

  if (data.format === FLOW_FORMAT && Array.isArray(data.nodes) && Array.isArray(data.edges)) {
    return createWorkflowDocument({
      nodes: data.nodes,
      edges: data.edges,
      viewport: data.viewport || null,
    }, data.componentTemplates || [], data.settings || {});
  }

  if (Array.isArray(data.nodes) && Array.isArray(data.links)) {
    return createWorkflowDocument(convertLiteGraphWorkflow(data));
  }

  throw new Error('Unsupported workflow format.');
}

export function serializeWorkflow(document) {
  return {
    format: FLOW_FORMAT,
    version: FLOW_VERSION,
    rootGraph: serializeGraph(document.rootGraph),
    componentTemplates: normalizeComponentTemplates(document.componentTemplates || []),
    settings: document.settings && typeof document.settings === 'object' ? document.settings : {},
  };
}

function buildEdgeDefaults(connection) {
  return {
    ...connection,
    id: createBrowserId('edge'),
    type: 'default',
    markerEnd: { type: MarkerType.ArrowClosed },
  };
}

function hasPath(sourceId, targetId, edges, visited = new Set()) {
  if (sourceId === targetId) {
    return true;
  }

  if (visited.has(sourceId)) {
    return false;
  }

  visited.add(sourceId);

  return edges
    .filter((edge) => edge.source === sourceId)
    .some((edge) => hasPath(edge.target, targetId, edges, visited));
}

export function isValidConnection(connection, nodes, edges) {
  if (!connection.source || !connection.target) {
    return false;
  }

  if (connection.source === connection.target) {
    return false;
  }

  const sourceNode = nodes.find((node) => node.id === connection.source);
  const targetNode = nodes.find((node) => node.id === connection.target);

  if (!sourceNode || !targetNode) {
    return false;
  }

  const sourceHandles = getNodeHandles(sourceNode.type, sourceNode.data).outputs;
  const targetHandles = getNodeHandles(targetNode.type, targetNode.data).inputs;
  const sourceHandle = sourceHandles.find((handle) => handle.id === connection.sourceHandle);
  const targetHandle = targetHandles.find((handle) => handle.id === connection.targetHandle);

  if (!sourceHandle || !targetHandle) {
    return false;
  }

  const sameConnection = edges.some(
    (edge) =>
      edge.source === connection.source &&
      edge.sourceHandle === connection.sourceHandle &&
      edge.target === connection.target &&
      edge.targetHandle === connection.targetHandle,
  );

  if (sameConnection) {
    return false;
  }

  const outputType = sourceHandle.dataType;
  const inputType = targetHandle.dataType;
  const typesCompatible = outputType === '*' || inputType === '*' || outputType === inputType;

  if (!typesCompatible) {
    return false;
  }

  return true;
}

export function connectEdge(connection, edges) {
  return addEdge(buildEdgeDefaults(connection), edges);
}

function getNodeSize(node) {
  return {
    width: node.style?.width || node.data?.width || 260,
    height: node.data?.height || 180,
  };
}

function getFirstOutputHandleId(node) {
  return getNodeHandles(node.type, node.data).outputs[0]?.id || 'output';
}

function getHandleLabel(node, direction, handleId, fallback) {
  const handles = getNodeHandles(node.type, node.data)[direction] || [];
  const handle = handles.find((candidate) => candidate.id === handleId) || handles[0];
  return handle?.label || handleId || fallback;
}

function createComponentHandleId(baseId, index, total) {
  return total === 1 ? baseId : `${baseId}-${index}`;
}

function getComponentBoundaryExternalHandleId(node, fallbackId, index = 0) {
  const rawHandleId = node?.data?.externalHandleId;

  if (typeof rawHandleId === 'string' && rawHandleId.trim()) {
    return rawHandleId.trim();
  }

  return index === 0 ? fallbackId : `${fallbackId}-${index}`;
}

function collectComponentOutputs(graph) {
  const outputNodes = (graph.nodes || []).filter((node) => node.type === COMPONENT_OUTPUT_TYPE);

  if (outputNodes.length === 0) {
    return {
      outputs: { output: null },
      lastOutput: null,
    };
  }

  const outputs = Object.fromEntries(
    outputNodes.map((node, index) => [
      getComponentBoundaryExternalHandleId(node, 'output', index),
      node.data?.runtime?.value ?? null,
    ]),
  );
  const values = Object.values(outputs);

  return {
    outputs,
    lastOutput: values.length === 1 ? values[0] : outputs,
  };
}

function cloneEdgeForSubgraph(edge) {
  return normalizeEdge({
    id: createBrowserId('edge'),
    source: edge.source,
    sourceHandle: edge.sourceHandle || null,
    target: edge.target,
    targetHandle: edge.targetHandle || null,
    type: edge.type === 'smoothstep' ? 'default' : edge.type || 'default',
  });
}

function createExternalEdge(source, sourceHandle, target, targetHandle) {
  return normalizeEdge({
    id: createBrowserId('edge'),
    source,
    sourceHandle,
    target,
    targetHandle,
    type: 'default',
  });
}

export function createComponentFromSelection(graph) {
  const selectedNodes = graph.nodes.filter((node) => node.selected);

  if (selectedNodes.length === 0) {
    return { error: 'Select at least one node to create a component.' };
  }

  if (selectedNodes.some((node) => isComponentBoundaryType(node.type))) {
    return { error: 'Component Input/Output nodes cannot be grouped into another component.' };
  }

  const selectedIds = new Set(selectedNodes.map((node) => node.id));
  const internalEdges = graph.edges.filter(
    (edge) => selectedIds.has(edge.source) && selectedIds.has(edge.target),
  );
  const incomingExternalEdges = graph.edges.filter(
    (edge) => !selectedIds.has(edge.source) && selectedIds.has(edge.target),
  );
  const outgoingExternalEdges = graph.edges.filter(
    (edge) => selectedIds.has(edge.source) && !selectedIds.has(edge.target),
  );

  const bounds = selectedNodes.reduce(
    (acc, node) => {
      const { width, height } = getNodeSize(node);
      return {
        minX: Math.min(acc.minX, node.position.x),
        minY: Math.min(acc.minY, node.position.y),
        maxX: Math.max(acc.maxX, node.position.x + width),
        maxY: Math.max(acc.maxY, node.position.y + height),
      };
    },
    {
      minX: Number.POSITIVE_INFINITY,
      minY: Number.POSITIVE_INFINITY,
      maxX: Number.NEGATIVE_INFINITY,
      maxY: Number.NEGATIVE_INFINITY,
    },
  );

  const offsetX = 180 - bounds.minX;
  const offsetY = 60 - bounds.minY;
  const nodeLookup = new Map(graph.nodes.map((node) => [node.id, node]));
  const outputX = Math.max(520, bounds.maxX - bounds.minX + 240);
  const portY = (index) => 80 + index * 120;

  const inputPorts =
    incomingExternalEdges.length > 0
      ? incomingExternalEdges.map((edge, index) => {
          const targetNode = nodeLookup.get(edge.target);
          const label = targetNode
            ? getHandleLabel(targetNode, 'inputs', edge.targetHandle || null, edge.targetHandle || 'input')
            : edge.targetHandle || 'input';
          const externalHandleId = createComponentHandleId('input', index, incomingExternalEdges.length);

          return {
            edge,
            externalHandleId,
            node: createNodeInstance(COMPONENT_INPUT_TYPE, { x: 30, y: portY(index) }, {
              data: {
                title: `Input: ${label}`,
                externalHandleId,
                externalLabel: label,
              },
            }),
          };
        })
      : [
          {
            edge: null,
            externalHandleId: 'input',
            node: createNodeInstance(COMPONENT_INPUT_TYPE, { x: 30, y: 110 }, {
              data: {
                externalHandleId: 'input',
                externalLabel: 'input',
              },
            }),
          },
        ];

  const outputPorts =
    outgoingExternalEdges.length > 0
      ? outgoingExternalEdges.map((edge, index) => {
          const sourceNode = nodeLookup.get(edge.source);
          const label = sourceNode
            ? getHandleLabel(sourceNode, 'outputs', edge.sourceHandle || null, edge.sourceHandle || 'output')
            : edge.sourceHandle || 'output';
          const externalHandleId = createComponentHandleId('output', index, outgoingExternalEdges.length);

          return {
            edge,
            externalHandleId,
            node: createNodeInstance(COMPONENT_OUTPUT_TYPE, { x: outputX, y: portY(index) }, {
              data: {
                title: `Output: ${label}`,
                externalHandleId,
                externalLabel: label,
              },
            }),
          };
        })
      : [
          {
            edge: null,
            externalHandleId: 'output',
            node: createNodeInstance(COMPONENT_OUTPUT_TYPE, { x: outputX, y: 110 }, {
              data: {
                externalHandleId: 'output',
                externalLabel: 'output',
              },
            }),
          },
        ];

  const normalizedSelectedNodes = selectedNodes.map((node) =>
    hydrateNode({
      ...node,
      selected: false,
      position: {
        x: node.position.x + offsetX,
        y: node.position.y + offsetY,
      },
    }),
  );

  const subgraphEdges = internalEdges.map((edge) => cloneEdgeForSubgraph(edge));

  inputPorts.forEach((port) => {
    if (!port.edge) {
      return;
    }

    subgraphEdges.push(
      createExternalEdge(port.node.id, 'output', port.edge.target, port.edge.targetHandle || null),
    );
  });

  if (outgoingExternalEdges.length > 0) {
    outputPorts.forEach((port) => {
      subgraphEdges.push(
        createExternalEdge(port.edge.source, port.edge.sourceHandle || null, port.node.id, 'input'),
      );
    });
  } else {
    const sinkNodes = normalizedSelectedNodes.filter((node) => {
      if (isComponentBoundaryType(node.type)) {
        return false;
      }

      const hasOutgoingInternalEdge = internalEdges.some((edge) => edge.source === node.id);
      const hasOutputs = getNodeHandles(node.type, node.data).outputs.length > 0;
      return !hasOutgoingInternalEdge && hasOutputs;
    });

    if (sinkNodes.length === 1) {
      subgraphEdges.push(
        createExternalEdge(
          sinkNodes[0].id,
          getFirstOutputHandleId(sinkNodes[0]),
          outputPorts[0].node.id,
          'input',
        ),
      );
    }
  }

  const componentNode = createNodeInstance(
    COMPONENT_NODE_TYPE,
    { x: bounds.minX, y: bounds.minY },
    {
      data: {
        title: 'Component',
        description: '',
        subgraph: {
          nodes: [
            ...inputPorts.map((port) => port.node),
            ...normalizedSelectedNodes,
            ...outputPorts.map((port) => port.node),
          ],
          edges: subgraphEdges,
          viewport: null,
        },
      },
    },
  );

  const remainingNodes = graph.nodes
    .filter((node) => !selectedIds.has(node.id))
    .map((node) => ({ ...node, selected: false }));
  const remainingEdges = graph.edges.filter(
    (edge) => !selectedIds.has(edge.source) && !selectedIds.has(edge.target),
  );

  const replacementEdges = [...remainingEdges];

  inputPorts.forEach((port) => {
    if (!port.edge) {
      return;
    }

    replacementEdges.push(
      createExternalEdge(
        port.edge.source,
        port.edge.sourceHandle || null,
        componentNode.id,
        port.externalHandleId,
      ),
    );
  });

  outputPorts.forEach((port) => {
    if (!port.edge) {
      return;
    }

    replacementEdges.push(
      createExternalEdge(
        componentNode.id,
        port.externalHandleId,
        port.edge.target,
        port.edge.targetHandle || null,
      ),
    );
  });

  return {
    graph: hydrateGraph({
      ...graph,
      nodes: [...remainingNodes, { ...componentNode, selected: true }],
      edges: replacementEdges,
    }),
    componentNodeId: componentNode.id,
  };
}

function buildIncomingEdgeMap(edges) {
  const incoming = new Map();
  const outgoing = new Map();

  edges.forEach((edge) => {
    if (!incoming.has(edge.target)) {
      incoming.set(edge.target, []);
    }
    if (!outgoing.has(edge.source)) {
      outgoing.set(edge.source, []);
    }

    incoming.get(edge.target).push(edge);
    outgoing.get(edge.source).push(edge);
  });

  return { incoming, outgoing };
}

function splitFeedbackEdges(edges) {
  const acyclicEdges = [];
  const feedbackEdges = [];

  edges.forEach((edge) => {
    if (hasPath(edge.target, edge.source, acyclicEdges)) {
      feedbackEdges.push(edge);
    } else {
      acyclicEdges.push(edge);
    }
  });

  return { acyclicEdges, feedbackEdges };
}

function topologicalSort(nodes, incomingMap) {
  const nodeLookup = new Map(nodes.map((node) => [node.id, node]));
  const visited = new Set();
  const visiting = new Set();
  const sorted = [];

  function visit(node) {
    if (visited.has(node.id)) {
      return;
    }

    if (visiting.has(node.id)) {
      throw new Error('Workflow contains a circular dependency.');
    }

    visiting.add(node.id);

    const incomingEdges = incomingMap.get(node.id) || [];
    incomingEdges.forEach((edge) => {
      const sourceNode = nodeLookup.get(edge.source);
      if (sourceNode) {
        visit(sourceNode);
      }
    });

    visiting.delete(node.id);
    visited.add(node.id);
    sorted.push(node);
  }

  nodes.forEach((node) => visit(node));
  return sorted;
}

function collectReachableNodeIds(startIds, edges) {
  const reachable = new Set(startIds);
  const outgoingBySource = new Map();

  edges.forEach((edge) => {
    outgoingBySource.set(edge.source, [...(outgoingBySource.get(edge.source) || []), edge]);
  });

  const queue = [...startIds];
  while (queue.length > 0) {
    const nodeId = queue.shift();
    (outgoingBySource.get(nodeId) || []).forEach((edge) => {
      if (!reachable.has(edge.target)) {
        reachable.add(edge.target);
        queue.push(edge.target);
      }
    });
  }

  return reachable;
}

function includeInputDependencyNodeIds(nodeIds, edges) {
  const required = new Set(nodeIds);
  const incomingByTarget = new Map();

  edges.forEach((edge) => {
    incomingByTarget.set(edge.target, [...(incomingByTarget.get(edge.target) || []), edge]);
  });

  const queue = [...nodeIds];
  while (queue.length > 0) {
    const nodeId = queue.shift();
    (incomingByTarget.get(nodeId) || []).forEach((edge) => {
      if (!required.has(edge.source)) {
        required.add(edge.source);
        queue.push(edge.source);
      }
    });
  }

  return required;
}

function getRuntimeOrder(nodes, edges, incomingMap) {
  const sortedNodes = topologicalSort(nodes, incomingMap);
  const startIds = nodes
    .filter((node) => node.type === 'basic/start')
    .map((node) => node.id);

  if (startIds.length === 0) {
    return sortedNodes;
  }

  const reachable = collectReachableNodeIds(startIds, edges);
  const required = includeInputDependencyNodeIds(reachable, edges);
  return sortedNodes.filter((node) => required.has(node.id));
}

function prepareGraphForRun(graph) {
  return hydrateGraph({
    ...graph,
    nodes: graph.nodes.map((node) =>
      hydrateNode({
        ...node,
        data: {
          ...node.data,
          runtime: {
            type: node.type,
            status: 'idle',
            error: '',
            inputs: {},
            outputs: {},
            ...(node.type === 'basic/dialog'
              ? {
                  messages: [],
                  cleared: true,
                }
              : {}),
          },
        },
      }),
    ),
  });
}

function updateNodeInGraph(graph, nodeId, updater) {
  return hydrateGraph({
    ...graph,
    nodes: graph.nodes.map((node) => {
      if (node.id !== nodeId) {
        return node;
      }

      return hydrateNode(updater(node));
    }),
  });
}

function updateNodeRuntime(graph, nodeId, runtimePatch) {
  return updateNodeInGraph(graph, nodeId, (node) => ({
    ...node,
    data: {
      ...node.data,
      runtime: {
        ...(node.data.runtime || {}),
        ...runtimePatch,
      },
    },
  }));
}

function collectInputsForNode(incomingEdges, outputsByNode) {
  const valuesByHandle = {};
  (incomingEdges || []).forEach((edge) => {
    const sourceOutputs = outputsByNode.get(edge.source) || {};
    const handleId = edge.targetHandle || 'input';
    const value = sourceOutputs[edge.sourceHandle];
    valuesByHandle[handleId] = [...(valuesByHandle[handleId] || []), value];
  });

  return Object.fromEntries(
    Object.entries(valuesByHandle).map(([handleId, values]) => [
      handleId,
      values.find((value) => value !== null && value !== undefined) ?? values[0],
    ]),
  );
}

function hasBlockedIncomingValue(incomingEdges, inputValues) {
  const targetHandles = new Set((incomingEdges || []).map((edge) => edge.targetHandle || 'input'));

  return [...targetHandles].some((handleId) => inputValues[handleId] === null || inputValues[handleId] === undefined);
}

function renderMemoryTemplate(text, memory = {}) {
  return String(text || '').replace(/\{([a-zA-Z0-9_.-]+)\}/g, (match, key) => {
    const value = memory[key];
    return value === undefined || value === null || value === '' ? match : String(value);
  });
}

function buildQuestionResult(node, inputValues, answer, memory = {}, questionOverride = '') {
  const question = questionOverride || renderMemoryTemplate(inputValues.question || node.data.question || '', memory);
  const dialogIn = Array.isArray(inputValues['dialog-in']) ? inputValues['dialog-in'] : [];
  const messages = [
    ...dialogIn,
    ...(String(question || '').trim() ? [{ type: 'character', text: question }] : []),
    {
      type: 'user',
      text: answer,
    },
  ];

  return {
    outputs: {
      answer,
      question,
      dialog: messages,
      turn: {
        answer,
        question,
        dialog: messages,
      },
    },
    runtime: {
      question,
      answer,
      messages,
    },
  };
}

function getFeedbackJump(runState, sourceNodeId, outputs = {}) {
  const feedbackEdges = runState.feedbackOutgoing?.get(sourceNodeId) || [];

  for (const edge of feedbackEdges) {
    const outputValue = outputs[edge.sourceHandle];
    if (outputValue === null || outputValue === undefined) {
      continue;
    }

    const targetIndex = runState.order.indexOf(edge.target);
    if (targetIndex === -1) {
      continue;
    }

    return {
      edge,
      targetIndex,
      outputValue,
    };
  }

  return null;
}

export function createInteractiveWorkflowRun(graph) {
  const workingGraph = prepareGraphForRun(graph);
  const { acyclicEdges, feedbackEdges } = splitFeedbackEdges(workingGraph.edges);
  const { incoming, outgoing } = buildIncomingEdgeMap(acyclicEdges);
  const { outgoing: feedbackOutgoing } = buildIncomingEdgeMap(feedbackEdges);
  const sortedNodes = getRuntimeOrder(workingGraph.nodes, workingGraph.edges, incoming);

  return {
    graph: workingGraph,
    incoming,
    outgoing,
    feedbackOutgoing,
    order: sortedNodes.map((node) => node.id),
    cursor: 0,
    outputsByNode: new Map(),
    inputOverridesByNode: new Map(),
    memory: {},
    assistantRole: DEFAULT_ASSISTANT_ROLE,
    retryCountsByNode: new Map(),
    componentRunsByNode: new Map(),
    pendingQuestion: null,
    completed: false,
  };
}

function wait(ms) {
  if (!ms) {
    return Promise.resolve();
  }

  return new Promise((resolve) => {
    window.setTimeout(resolve, ms);
  });
}

export async function continueInteractiveWorkflowRun(runState, options) {
  const {
    backendUrl,
    llmProvider = 'ollama',
    llmSessionId = '',
    userAnswer = null,
    externalInputValue = null,
    externalInputValues = null,
    knowledgeContextId = '',
    testRun = null,
    onGraphChange = null,
    onEvent = null,
    animate = true,
  } = options;

  let workingGraph = runState.graph;

  if (onGraphChange) {
    onGraphChange(workingGraph);
  }

  if (runState.pendingQuestion) {
    if (runState.pendingQuestion.componentNodeId) {
      const componentNodeId = runState.pendingQuestion.componentNodeId;
      const componentNode = workingGraph.nodes.find(
        (candidate) => candidate.id === componentNodeId && isComponentNodeType(candidate.type),
      );
      const componentRun = runState.componentRunsByNode?.get(componentNodeId);
      const componentInputValues = runState.pendingQuestion.componentInputValues || {};

      if (!componentNode || !componentRun) {
        throw new Error('Pending component question was not found.');
      }

      componentRun.memory = runState.memory || {};
      componentRun.assistantRole = runState.assistantRole || DEFAULT_ASSISTANT_ROLE;

      const componentResult = await continueInteractiveWorkflowRun(componentRun, {
        backendUrl,
        llmProvider,
        llmSessionId,
        userAnswer,
        externalInputValue: componentInputValues.input ?? null,
        externalInputValues: componentInputValues,
        knowledgeContextId,
        testRun,
        animate: false,
        onGraphChange: (nextSubgraph) => {
          workingGraph = updateNodeInGraph(workingGraph, componentNodeId, (currentNode) => ({
            ...currentNode,
            data: {
              ...currentNode.data,
              subgraph: nextSubgraph,
            },
          }));

          if (onGraphChange) {
            onGraphChange(workingGraph);
          }
        },
        onEvent,
      });

      runState.memory = componentResult.state.memory || runState.memory || {};
      runState.assistantRole = componentResult.state.assistantRole || runState.assistantRole || DEFAULT_ASSISTANT_ROLE;
      runState.componentRunsByNode.set(componentNodeId, componentResult.state);
      workingGraph = updateNodeInGraph(workingGraph, componentNodeId, (currentNode) => ({
        ...currentNode,
        data: {
          ...currentNode.data,
          subgraph: componentResult.state.graph,
        },
      }));

      if (componentResult.status === 'paused') {
        const pendingQuestion = {
          ...componentResult.pendingQuestion,
          componentNodeId,
          componentInputValues,
        };

        runState.pendingQuestion = pendingQuestion;
        workingGraph = updateNodeRuntime(workingGraph, componentNodeId, {
          status: 'waiting',
          error: '',
          inputs: componentInputValues,
          outputs: {},
        });

        if (onGraphChange) {
          onGraphChange(workingGraph);
        }

        return {
          status: 'paused',
          state: {
            ...runState,
            graph: workingGraph,
            pendingQuestion,
          },
          pendingQuestion,
        };
      }

      if (componentResult.status === 'restart') {
        runState.pendingQuestion = null;
        return {
          status: 'restart',
          state: {
            ...runState,
            graph: workingGraph,
            pendingQuestion: null,
          },
          pendingQuestion: null,
        };
      }

      const componentOutputs = collectComponentOutputs(componentResult.state.graph);
      runState.outputsByNode.set(componentNodeId, componentOutputs.outputs);
      runState.componentRunsByNode.delete(componentNodeId);
      runState.pendingQuestion = null;
      runState.cursor += 1;

      workingGraph = updateNodeRuntime(workingGraph, componentNodeId, {
        status: 'success',
        error: '',
        inputs: componentInputValues,
        outputs: componentOutputs.outputs,
        lastOutput: componentOutputs.lastOutput,
      });

      if (onGraphChange) {
        onGraphChange(workingGraph);
      }
    } else {
      if (userAnswer === null || userAnswer === undefined || String(userAnswer).trim() === '') {
        return {
          status: 'paused',
          state: {
            ...runState,
            graph: workingGraph,
          },
          pendingQuestion: runState.pendingQuestion,
        };
      }

      const pendingNode = workingGraph.nodes.find((candidate) => candidate.id === runState.pendingQuestion.nodeId);
      if (!pendingNode) {
        throw new Error('Pending question node was not found.');
      }

      const answer = String(userAnswer).trim();

      if (runState.pendingQuestion.retryForNodeId) {
        const retryDialog = [
          ...(Array.isArray(runState.pendingQuestion.inputs?.['dialog-in'])
            ? runState.pendingQuestion.inputs['dialog-in']
            : []),
          ...(String(runState.pendingQuestion.question || '').trim()
            ? [{ type: 'character', text: runState.pendingQuestion.question }]
            : []),
          {
            type: 'user',
            text: answer,
          },
        ];
        runState.inputOverridesByNode.set(runState.pendingQuestion.retryForNodeId, {
          answer,
          question: runState.pendingQuestion.question,
          'dialog-in': retryDialog,
        });

        if (onEvent) {
          onEvent({
            type: 'user-answer',
            nodeId: pendingNode.id,
            answer,
          });
        }

        workingGraph = updateNodeRuntime(workingGraph, pendingNode.id, {
          status: 'running',
          error: '',
        });

        runState.pendingQuestion = null;

        if (onGraphChange) {
          onGraphChange(workingGraph);
        }
      } else {
        const result = buildQuestionResult(
          pendingNode,
          runState.pendingQuestion.inputs,
          answer,
          runState.memory || {},
          runState.pendingQuestion.question,
        );

        runState.outputsByNode.set(pendingNode.id, result.outputs);
        workingGraph = updateNodeRuntime(workingGraph, pendingNode.id, {
          status: 'success',
          error: '',
          inputs: runState.pendingQuestion.inputs,
          outputs: result.outputs,
          ...result.runtime,
        });

        if (onEvent) {
          onEvent({
            type: 'user-answer',
            nodeId: pendingNode.id,
            answer,
          });
        }

        runState.pendingQuestion = null;
        runState.cursor += 1;

        if (onGraphChange) {
          onGraphChange(workingGraph);
        }
      }
    }
  }

  while (runState.cursor < runState.order.length) {
    const nodeId = runState.order[runState.cursor];
    const node = workingGraph.nodes.find((candidate) => candidate.id === nodeId);

    if (!node) {
      runState.cursor += 1;
      continue;
    }

    const definition = getNodeDefinition(node.type);
    const incomingEdges = runState.incoming.get(node.id) || [];
    const inputValues = {
      ...collectInputsForNode(incomingEdges, runState.outputsByNode),
      ...(runState.inputOverridesByNode.get(node.id) || {}),
    };

    if (incomingEdges.length > 0 && hasBlockedIncomingValue(incomingEdges, inputValues)) {
      runState.outputsByNode.set(node.id, {});
      workingGraph = updateNodeRuntime(workingGraph, node.id, {
        status: 'skipped',
        error: '',
        inputs: inputValues,
        outputs: {},
      });

      if (onEvent) {
        onEvent({
          type: 'skip',
          nodeId: node.id,
          title: node.data?.title || node.type,
        });
      }

      if (onGraphChange) {
        onGraphChange(workingGraph);
      }

      runState.cursor += 1;
      continue;
    }

    workingGraph = updateNodeRuntime(workingGraph, node.id, {
      status: 'running',
      error: '',
      inputs: inputValues,
    });

    if (onEvent) {
      onEvent({
        type: 'node-start',
        nodeId: node.id,
        title: node.data?.title || node.type,
      });
    }

    if (onGraphChange) {
      onGraphChange(workingGraph);
    }

    await wait(animate ? 80 : 0);

    if (node.type === 'basic/question') {
      const renderedQuestion = renderMemoryTemplate(inputValues.question || node.data.question || '', runState.memory || {});
      const question = node.data?.paraphrase
        ? await paraphraseText(backendUrl, renderedQuestion, 'question', testRun, node.id, llmProvider, llmSessionId, runState.assistantRole || DEFAULT_ASSISTANT_ROLE)
        : renderedQuestion;
      const pendingQuestion = {
        nodeId: node.id,
        question,
        inputs: inputValues,
      };

      workingGraph = updateNodeRuntime(workingGraph, node.id, {
        status: 'waiting',
        error: '',
        inputs: inputValues,
        outputs: {},
        question,
      });

      if (onEvent) {
        onEvent({
          type: 'assistant-question',
          nodeId: node.id,
          question,
        });
      }

      if (onGraphChange) {
        onGraphChange(workingGraph);
      }

      return {
        status: 'paused',
        state: {
          ...runState,
          graph: workingGraph,
          pendingQuestion,
        },
        pendingQuestion,
      };
    }

    try {
      let result;

      if (isComponentNodeType(node.type)) {
        const componentSubgraph = node.data.subgraph || createComponentSubgraph();
        const componentRun = createInteractiveWorkflowRun(componentSubgraph);
        componentRun.memory = runState.memory || {};
        componentRun.assistantRole = runState.assistantRole || DEFAULT_ASSISTANT_ROLE;
        runState.componentRunsByNode.set(node.id, componentRun);

        const subgraphResult = await continueInteractiveWorkflowRun(componentRun, {
          backendUrl,
          llmProvider,
          llmSessionId,
          externalInputValue: inputValues.input ?? null,
          externalInputValues: inputValues,
          knowledgeContextId,
          testRun,
          animate: false,
          onGraphChange: (nextSubgraph) => {
            workingGraph = updateNodeInGraph(workingGraph, node.id, (currentNode) => ({
              ...currentNode,
              data: {
                ...currentNode.data,
                subgraph: nextSubgraph,
              },
            }));

            if (onGraphChange) {
              onGraphChange(workingGraph);
            }
          },
          onEvent,
        });

        runState.memory = subgraphResult.state.memory || runState.memory || {};
        runState.assistantRole = subgraphResult.state.assistantRole || runState.assistantRole || DEFAULT_ASSISTANT_ROLE;
        runState.componentRunsByNode.set(node.id, subgraphResult.state);

        if (subgraphResult.status === 'paused') {
          const pendingQuestion = {
            ...subgraphResult.pendingQuestion,
            componentNodeId: node.id,
            componentInputValues: inputValues,
          };

          workingGraph = updateNodeRuntime(workingGraph, node.id, {
            status: 'waiting',
            error: '',
            inputs: inputValues,
            outputs: {},
          });

          if (onGraphChange) {
            onGraphChange(workingGraph);
          }

          return {
            status: 'paused',
            state: {
              ...runState,
              graph: workingGraph,
              pendingQuestion,
            },
            pendingQuestion,
          };
        }

        if (subgraphResult.status === 'restart') {
          return {
            status: 'restart',
            state: {
              ...runState,
              graph: workingGraph,
              pendingQuestion: null,
            },
            pendingQuestion: null,
          };
        }

        const componentResult = collectComponentOutputs(subgraphResult.state.graph);
        runState.componentRunsByNode.delete(node.id);

        result = {
          outputs: componentResult.outputs,
          runtime: {
            lastOutput: componentResult.lastOutput,
            assistantRole: runState.assistantRole || DEFAULT_ASSISTANT_ROLE,
          },
          subgraph: subgraphResult.graph,
        };
      } else if (definition?.execute) {
        const nodeLookup = new Map(workingGraph.nodes.map((candidate) => [candidate.id, candidate]));
        result = await definition.execute({
          node: nodeLookup.get(node.id),
          inputs: inputValues,
          backendUrl,
          llmProvider,
          llmSessionId,
          externalInputValue,
          externalInputValues,
          memory: runState.memory || {},
          assistantRole: runState.assistantRole || DEFAULT_ASSISTANT_ROLE,
          knowledgeContextId,
          testRun,
          connectedOutputHandles: new Set((runState.outgoing.get(node.id) || []).map((edge) => edge.sourceHandle)),
          outgoingEdges: runState.outgoing.get(node.id) || [],
          nodeLookup,
        });
      } else {
        result = {
          outputs: {},
          runtime: {},
        };
      }

      if (result.subgraph) {
        workingGraph = updateNodeInGraph(workingGraph, node.id, (currentNode) => ({
          ...currentNode,
          data: {
            ...currentNode.data,
            subgraph: result.subgraph,
          },
        }));
      }

      if (result.runtimeAction?.type === 'restart') {
        workingGraph = updateNodeRuntime(workingGraph, node.id, {
          status: 'success',
          error: '',
          inputs: inputValues,
          outputs: result.outputs || {},
          ...(result.runtime || {}),
        });

        if (onEvent) {
          onEvent({
            type: 'restart',
            nodeId: node.id,
            title: node.data?.title || node.type,
          });
        }

        if (onGraphChange) {
          onGraphChange(workingGraph);
        }

        return {
          status: 'restart',
          state: {
            ...runState,
            graph: workingGraph,
            pendingQuestion: null,
          },
          pendingQuestion: null,
        };
      }

      const canRetryUnclear =
        (node.type === 'basic/semantic-branch' || node.type === 'basic/save-memory') &&
        result.runtime?.matchId === 'unclear' &&
        node.data?.retryOnUnclear !== false;

      if (canRetryUnclear) {
        const retryCount = runState.retryCountsByNode.get(node.id) || 0;
        const defaultRetryQuestion = 'Не смогла уверенно понять ответ. Пожалуйста, ответьте ближе к одному из вариантов.';
        const rawRetryQuestion = typeof node.data?.retryQuestion === 'string'
          ? node.data.retryQuestion
          : defaultRetryQuestion;
        const retryQuestionTemplate = renderMemoryTemplate(
          rawRetryQuestion,
          runState.memory || {},
        );
        const renderedRetryQuestion = node.type === 'basic/save-memory'
          ? retryQuestionTemplate.replace(/\{text\}/g, inputValues.text || '')
          : retryQuestionTemplate;
        runState.retryCountsByNode.set(node.id, retryCount + 1);
        const retryQuestion = node.data?.retryParaphrase
          ? await paraphraseText(backendUrl, renderedRetryQuestion, 'question', testRun, node.id, llmProvider, llmSessionId, runState.assistantRole || DEFAULT_ASSISTANT_ROLE)
          : renderedRetryQuestion;
        const pendingQuestion = {
          nodeId: node.id,
          retryForNodeId: node.id,
          question: retryQuestion,
          inputs: inputValues,
        };

        workingGraph = updateNodeRuntime(workingGraph, node.id, {
          status: 'waiting',
          error: '',
          inputs: inputValues,
          outputs: {},
          result: 'unclear',
          matchId: 'unclear',
          retryCount: retryCount + 1,
        });

        if (onEvent) {
          onEvent({
            type: 'assistant-question',
            nodeId: node.id,
            question: retryQuestion,
          });
        }

        if (onGraphChange) {
          onGraphChange(workingGraph);
        }

        return {
          status: 'paused',
          state: {
            ...runState,
            graph: workingGraph,
            pendingQuestion,
          },
          pendingQuestion,
        };
      }

      runState.outputsByNode.set(node.id, result.outputs || {});
      runState.inputOverridesByNode.delete(node.id);
      if (result.memoryPatch && typeof result.memoryPatch === 'object') {
        runState.memory = {
          ...(runState.memory || {}),
          ...result.memoryPatch,
        };
      }
      if (typeof result.assistantRolePatch === 'string') {
        runState.assistantRole = result.assistantRolePatch || DEFAULT_ASSISTANT_ROLE;
      }

      workingGraph = updateNodeRuntime(workingGraph, node.id, {
        status: 'success',
        error: '',
        inputs: inputValues,
        outputs: result.outputs || {},
        ...(result.runtime || {}),
        assistantRole: runState.assistantRole || DEFAULT_ASSISTANT_ROLE,
      });

      if (onEvent) {
        onEvent({
          type: 'node-success',
          nodeId: node.id,
          title: node.data?.title || node.type,
        });

        if (result.runtime?.assistantMessage) {
          onEvent({
            type: 'assistant-message',
            nodeId: node.id,
            message: result.runtime.assistantMessage,
          });
        }

        if (result.memoryPatch && typeof result.memoryPatch === 'object') {
          onEvent({
            type: 'memory-update',
            nodeId: node.id,
            memoryPatch: result.memoryPatch,
          });
        }

        if (typeof result.assistantRolePatch === 'string') {
          onEvent({
            type: 'assistant-role-update',
            nodeId: node.id,
            assistantRole: runState.assistantRole || DEFAULT_ASSISTANT_ROLE,
          });
        }
      }

      if (onGraphChange) {
        onGraphChange(workingGraph);
      }

      const feedbackJump = getFeedbackJump(runState, node.id, result.outputs || {});
      if (feedbackJump) {
        const currentOverrides = runState.inputOverridesByNode.get(feedbackJump.edge.target) || {};
        runState.inputOverridesByNode.set(feedbackJump.edge.target, {
          ...currentOverrides,
          [feedbackJump.edge.targetHandle || 'input']: feedbackJump.outputValue,
        });
        runState.cursor = feedbackJump.targetIndex;
        await wait(animate ? 24 : 0);
        continue;
      }
    } catch (error) {
      runState.outputsByNode.set(node.id, {});
      workingGraph = updateNodeRuntime(workingGraph, node.id, {
        status: 'error',
        error: error instanceof Error ? error.message : String(error),
        inputs: inputValues,
        outputs: {},
      });

      if (onEvent) {
        onEvent({
          type: 'node-error',
          nodeId: node.id,
          title: node.data?.title || node.type,
          error: error instanceof Error ? error.message : String(error),
        });
      }

      if (onGraphChange) {
        onGraphChange(workingGraph);
      }
    }

    runState.cursor += 1;
    await wait(animate ? 24 : 0);
  }

  return {
    status: 'complete',
    state: {
      ...runState,
      graph: workingGraph,
      completed: true,
      pendingQuestion: null,
    },
    pendingQuestion: null,
  };
}

async function executeGraph(graph, options) {
  const {
    backendUrl,
    llmProvider = 'ollama',
    llmSessionId = '',
    externalInputValue = null,
    externalInputValues = null,
    onGraphChange = null,
    animate = false,
  } = options;

  let workingGraph = prepareGraphForRun(graph);
  const { acyclicEdges } = splitFeedbackEdges(workingGraph.edges);
  const { incoming, outgoing } = buildIncomingEdgeMap(acyclicEdges);
  const sortedNodes = getRuntimeOrder(workingGraph.nodes, workingGraph.edges, incoming);
  const outputsByNode = new Map();

  if (onGraphChange) {
    onGraphChange(workingGraph);
  }

  for (const node of sortedNodes) {
    const definition = getNodeDefinition(node.type);
    const inputValues = collectInputsForNode(incoming.get(node.id), outputsByNode);

    workingGraph = updateNodeRuntime(workingGraph, node.id, {
      status: 'running',
      error: '',
      inputs: inputValues,
    });

    if (onGraphChange) {
      onGraphChange(workingGraph);
    }

    await wait(animate ? 80 : 0);

    try {
      let result;

      if (isComponentNodeType(node.type)) {
        const componentSubgraph = node.data.subgraph || createComponentSubgraph();
        const subgraphResult = await executeGraph(componentSubgraph, {
          backendUrl,
          llmProvider,
          llmSessionId,
          externalInputValue: inputValues.input ?? null,
          externalInputValues: inputValues,
          animate: false,
        });
        const componentResult = collectComponentOutputs(subgraphResult.graph);

        result = {
          outputs: componentResult.outputs,
          runtime: {
            lastOutput: componentResult.lastOutput,
          },
          subgraph: subgraphResult.graph,
        };
      } else if (definition?.execute) {
        const nodeLookup = new Map(workingGraph.nodes.map((candidate) => [candidate.id, candidate]));
        result = await definition.execute({
          node: nodeLookup.get(node.id),
          inputs: inputValues,
          backendUrl,
          llmProvider,
          llmSessionId,
          externalInputValue,
          externalInputValues,
          connectedOutputHandles: new Set((outgoing.get(node.id) || []).map((edge) => edge.sourceHandle)),
          outgoingEdges: outgoing.get(node.id) || [],
          nodeLookup,
        });
      } else {
        result = {
          outputs: {},
          runtime: {},
        };
      }

      if (result.subgraph) {
        workingGraph = updateNodeInGraph(workingGraph, node.id, (currentNode) => ({
          ...currentNode,
          data: {
            ...currentNode.data,
            subgraph: result.subgraph,
          },
        }));
      }

      outputsByNode.set(node.id, result.outputs || {});

      workingGraph = updateNodeRuntime(workingGraph, node.id, {
        status: 'success',
        error: '',
        inputs: inputValues,
        outputs: result.outputs || {},
        ...(result.runtime || {}),
      });

      if (onGraphChange) {
        onGraphChange(workingGraph);
      }
    } catch (error) {
      outputsByNode.set(node.id, {});
      workingGraph = updateNodeRuntime(workingGraph, node.id, {
        status: 'error',
        error: error instanceof Error ? error.message : String(error),
        inputs: inputValues,
        outputs: {},
      });

      if (onGraphChange) {
        onGraphChange(workingGraph);
      }
    }

    await wait(animate ? 24 : 0);
  }

  return {
    graph: workingGraph,
    order: sortedNodes.map((node) => node.id),
  };
}

export async function executeWorkflow({ graph, backendUrl, llmProvider = 'ollama', llmSessionId = '', onGraphChange }) {
  return executeGraph(graph, {
    backendUrl,
    llmProvider,
    llmSessionId,
    onGraphChange,
    animate: true,
  });
}