import {
  isSpanNode,
  isTraceErrorNode,
  isTransactionNode,
} from 'sentry/views/performance/newTraceDetails/guards';
import type {
  TraceTree,
  TraceTreeNode,
} from 'sentry/views/performance/newTraceDetails/traceTree';

export type TraceSearchAction =
  | {query: string | undefined; type: 'set query'}
  | {type: 'go to next match'}
  | {type: 'go to previous match'}
  | {resultIndex: number; resultIteratorIndex: number; type: 'set iterator index'}
  | {type: 'clear iterator index'}
  | {type: 'clear query'}
  | {
      results: ReadonlyArray<TraceResult>;
      resultsLookup: Map<TraceTreeNode<TraceTree.NodeValue>, number>;
      type: 'set results';
    };

export type TraceSearchState = {
  query: string | undefined;
  resultIndex: number | undefined;
  resultIteratorIndex: number | undefined;
  results: ReadonlyArray<TraceResult> | undefined;
  resultsLookup: Map<TraceTreeNode<TraceTree.NodeValue>, number>;
  status: [ts: number, 'loading' | 'success' | 'error'] | undefined;
};

function assertBoundedIndex(index: number, length: number) {
  if (index < 0 || index > length - 1) {
    throw new Error('Search index out of bounds');
  }
}

export function traceSearchReducer(
  state: TraceSearchState,
  action: TraceSearchAction
): TraceSearchState {
  switch (action.type) {
    case 'clear query': {
      return {
        query: undefined,
        resultIteratorIndex: undefined,
        results: undefined,
        resultIndex: undefined,
        resultsLookup: new Map(),
        status: undefined,
      };
    }
    case 'go to next match': {
      if (state.resultIteratorIndex === undefined) {
        if (!state.results || state.results.length === 0) {
          return state;
        }
        return {...state, resultIteratorIndex: 0, resultIndex: state.results[0].index};
      }
      if (!state.results) return state;

      let next = state.resultIteratorIndex + 1;
      if (next > state.results.length - 1) {
        next = 0;
      }

      assertBoundedIndex(next, state.results.length);
      return {
        ...state,
        resultIteratorIndex: next,
        resultIndex: state.results[next].index,
      };
    }
    case 'go to previous match': {
      if (state.resultIteratorIndex === undefined) {
        if (!state.results || !state.results.length) {
          return state;
        }
        return {
          ...state,
          resultIteratorIndex: state.results.length - 1,
          resultIndex: state.results[state.results.length - 1].index,
        };
      }
      if (!state.results) return state;

      let previous = state.resultIteratorIndex - 1;
      if (previous < 0) {
        previous = state.results.length - 1;
      }

      assertBoundedIndex(previous, state.results.length);
      return {
        ...state,
        resultIteratorIndex: previous,
        resultIndex: state.results[previous].index,
      };
    }
    case 'set results': {
      return {
        ...state,
        status: [performance.now(), 'success'],
        results: action.results,
        resultIteratorIndex: undefined,
        resultIndex: undefined,
        resultsLookup: action.resultsLookup,
      };
    }
    case 'set query': {
      return {
        ...state,
        status: [performance.now(), 'loading'],
        query: action.query,
        resultIteratorIndex: undefined,
        resultIndex: undefined,
        resultsLookup: new Map(),
      };
    }

    case 'set iterator index': {
      return {
        ...state,
        resultIteratorIndex: action.resultIteratorIndex,
        resultIndex: action.resultIndex,
      };
    }

    case 'clear iterator index': {
      return {...state, resultIteratorIndex: undefined, resultIndex: undefined};
    }

    default: {
      throw new Error('Invalid trace search reducer action');
    }
  }
}

type TraceResult = {
  index: number;
  value: TraceTreeNode<TraceTree.NodeValue>;
};

export function searchInTraceTree(
  query: string,
  tree: TraceTree,
  cb: (
    results: [ReadonlyArray<TraceResult>, Map<TraceTreeNode<TraceTree.NodeValue>, number>]
  ) => void
): {id: number | null} {
  const raf: {id: number | null} = {id: 0};
  const results: Array<TraceResult> = [];
  const resultLookup = new Map();

  let i = 0;
  let matchCount = 0;
  const count = tree.list.length;

  function search() {
    const ts = performance.now();

    while (i < count && performance.now() - ts < 12) {
      const node = tree.list[i];
      if (searchInTraceSubset(query, node)) {
        results.push({index: i, value: node});
        resultLookup.set(node, matchCount);
        matchCount++;
      }
      i++;
    }

    if (i < count) {
      raf.id = requestAnimationFrame(search);
    }

    if (i === count) {
      cb([results, resultLookup]);
      raf.id = null;
    }
  }

  raf.id = requestAnimationFrame(search);
  return raf;
}

function searchInTraceSubset(
  query: string,
  node: TraceTreeNode<TraceTree.NodeValue>
): boolean {
  if (isSpanNode(node)) {
    if (node.value.op?.includes(query)) {
      return true;
    }
    if (node.value.description?.includes(query)) {
      return true;
    }
    if (node.value.span_id && node.value.span_id === query) {
      return true;
    }
  }

  if (isTransactionNode(node)) {
    if (node.value['transaction.op']?.includes(query)) {
      return true;
    }
    if (node.value.transaction?.includes(query)) {
      return true;
    }
    if (node.value.event_id && node.value.event_id === query) {
      return true;
    }
  }

  if (isTraceErrorNode(node)) {
    if (node.value.level === query) {
      return true;
    }
    if (node.value.title?.includes(query)) {
      return true;
    }
  }

  return false;
}