import { warn } from '../log.mjs';
import { createStringifyContext } from '../stringify/stringify.mjs';
import { isAlias, isSeq, isScalar, isMap, isNode } from './Node.mjs';
import { Scalar } from './Scalar.mjs';
import { toJS } from './toJS.mjs';

const MERGE_KEY = '<<';
function addPairToJSMap(ctx, map, {
  key,
  value
}) {
  if (ctx?.doc.schema.merge && isMergeKey(key)) {
    value = isAlias(value) ? value.resolve(ctx.doc) : value;
    if (isSeq(value)) for (const it of value.items) mergeToJSMap(ctx, map, it);else if (Array.isArray(value)) for (const it of value) mergeToJSMap(ctx, map, it);else mergeToJSMap(ctx, map, value);
  } else {
    const jsKey = toJS(key, '', ctx);
    if (map instanceof Map) {
      map.set(jsKey, toJS(value, jsKey, ctx));
    } else if (map instanceof Set) {
      map.add(jsKey);
    } else {
      const stringKey = stringifyKey(key, jsKey, ctx);
      const jsValue = toJS(value, stringKey, ctx);
      if (stringKey in map) Object.defineProperty(map, stringKey, {
        value: jsValue,
        writable: true,
        enumerable: true,
        configurable: true
      });else map[stringKey] = jsValue;
    }
  }
  return map;
}
const isMergeKey = key => key === MERGE_KEY || isScalar(key) && key.value === MERGE_KEY && (!key.type || key.type === Scalar.PLAIN);
// If the value associated with a merge key is a single mapping node, each of
// its key/value pairs is inserted into the current mapping, unless the key
// already exists in it. If the value associated with the merge key is a
// sequence, then this sequence is expected to contain mapping nodes and each
// of these nodes is merged in turn according to its order in the sequence.
// Keys in mapping nodes earlier in the sequence override keys specified in
// later mapping nodes. -- http://yaml.org/type/merge.html
function mergeToJSMap(ctx, map, value) {
  const source = ctx && isAlias(value) ? value.resolve(ctx.doc) : value;
  if (!isMap(source)) throw new Error('Merge sources must be maps or map aliases');
  const srcMap = source.toJSON(null, ctx, Map);
  for (const [key, value] of srcMap) {
    if (map instanceof Map) {
      if (!map.has(key)) map.set(key, value);
    } else if (map instanceof Set) {
      map.add(key);
    } else if (!Object.prototype.hasOwnProperty.call(map, key)) {
      Object.defineProperty(map, key, {
        value,
        writable: true,
        enumerable: true,
        configurable: true
      });
    }
  }
  return map;
}
function stringifyKey(key, jsKey, ctx) {
  if (jsKey === null) return '';
  if (typeof jsKey !== 'object') return String(jsKey);
  if (isNode(key) && ctx && ctx.doc) {
    const strCtx = createStringifyContext(ctx.doc, {});
    strCtx.anchors = new Set();
    for (const node of ctx.anchors.keys()) strCtx.anchors.add(node.anchor);
    strCtx.inFlow = true;
    strCtx.inStringifyKey = true;
    const strKey = key.toString(strCtx);
    if (!ctx.mapKeyWarned) {
      let jsonStr = JSON.stringify(strKey);
      if (jsonStr.length > 40) jsonStr = jsonStr.substring(0, 36) + '..."';
      warn(ctx.doc.options.logLevel, `Keys with collection values will be stringified due to JS Object restrictions: ${jsonStr}. Set mapAsMap: true to use object keys.`);
      ctx.mapKeyWarned = true;
    }
    return strKey;
  }
  return JSON.stringify(jsKey);
}

export { addPairToJSMap };
