'use strict';

const cleanPositionalOperators = require('../schema/cleanPositionalOperators');
const handleTimestampOption = require('../schema/handleTimestampOption');

module.exports = applyTimestampsToChildren;

/*!
 * ignore
 */

function applyTimestampsToChildren(now, update, schema) {
  if (update == null) {
    return;
  }

  const keys = Object.keys(update);
  let key;
  let createdAt;
  let updatedAt;
  let timestamps;
  let path;

  const hasDollarKey = keys.length && keys[0].startsWith('$');

  if (hasDollarKey) {
    if (update.$push) {
      for (key in update.$push) {
        const $path = schema.path(key);
        if (update.$push[key] &&
            $path &&
            $path.$isMongooseDocumentArray &&
            $path.schema.options.timestamps) {
          timestamps = $path.schema.options.timestamps;
          createdAt = handleTimestampOption(timestamps, 'createdAt');
          updatedAt = handleTimestampOption(timestamps, 'updatedAt');
          if (update.$push[key].$each) {
            update.$push[key].$each.forEach(function(subdoc) {
              if (updatedAt != null) {
                subdoc[updatedAt] = now;
              }
              if (createdAt != null) {
                subdoc[createdAt] = now;
              }
            });
          } else {
            if (updatedAt != null) {
              update.$push[key][updatedAt] = now;
            }
            if (createdAt != null) {
              update.$push[key][createdAt] = now;
            }
          }
        }
      }
    }
    if (update.$set != null) {
      const keys = Object.keys(update.$set);
      for (key of keys) {
        // Replace positional operator `$` and array filters `$[]` and `$[.*]`
        const keyToSearch = cleanPositionalOperators(key);
        path = schema.path(keyToSearch);
        if (!path) {
          continue;
        }

        const parentSchemaTypes = [];
        const pieces = keyToSearch.split('.');
        for (let i = pieces.length - 1; i > 0; --i) {
          const s = schema.path(pieces.slice(0, i).join('.'));
          if (s != null &&
            (s.$isMongooseDocumentArray || s.$isSingleNested)) {
            parentSchemaTypes.push({ parentPath: key.split('.').slice(0, i).join('.'), parentSchemaType: s });
          }
        }

        if (Array.isArray(update.$set[key]) && path.$isMongooseDocumentArray) {
          applyTimestampsToDocumentArray(update.$set[key], path, now);
        } else if (update.$set[key] && path.$isSingleNested) {
          applyTimestampsToSingleNested(update.$set[key], path, now);
        } else if (parentSchemaTypes.length > 0) {
          for (const item of parentSchemaTypes) {
            const parentPath = item.parentPath;
            const parentSchemaType = item.parentSchemaType;
            timestamps = parentSchemaType.schema.options.timestamps;
            createdAt = handleTimestampOption(timestamps, 'createdAt');
            updatedAt = handleTimestampOption(timestamps, 'updatedAt');

            if (!timestamps || updatedAt == null) {
              continue;
            }

            if (parentSchemaType.$isSingleNested) {
              // Single nested is easy
              update.$set[parentPath + '.' + updatedAt] = now;
              continue;
            }

            if (parentSchemaType.$isMongooseDocumentArray) {
              let childPath = key.substr(parentPath.length + 1);

              if (/^\d+$/.test(childPath)) {
                update.$set[parentPath + '.' + childPath][updatedAt] = now;
                continue;
              }

              const firstDot = childPath.indexOf('.');
              childPath = firstDot !== -1 ? childPath.substr(0, firstDot) : childPath;

              update.$set[parentPath + '.' + childPath + '.' + updatedAt] = now;
            }
          }
        } else if (path.schema != null && path.schema != schema && update.$set[key]) {
          timestamps = path.schema.options.timestamps;
          createdAt = handleTimestampOption(timestamps, 'createdAt');
          updatedAt = handleTimestampOption(timestamps, 'updatedAt');

          if (!timestamps) {
            continue;
          }

          if (updatedAt != null) {
            update.$set[key][updatedAt] = now;
          }
          if (createdAt != null) {
            update.$set[key][createdAt] = now;
          }
        }
      }
    }
  } else {
    const keys = Object.keys(update).filter(key => !key.startsWith('$'));
    for (key of keys) {
      // Replace positional operator `$` and array filters `$[]` and `$[.*]`
      const keyToSearch = cleanPositionalOperators(key);
      path = schema.path(keyToSearch);
      if (!path) {
        continue;
      }

      if (Array.isArray(update[key]) && path.$isMongooseDocumentArray) {
        applyTimestampsToDocumentArray(update[key], path, now);
      } else if (update[key] != null && path.$isSingleNested) {
        applyTimestampsToSingleNested(update[key], path, now);
      }
    }
  }
}

function applyTimestampsToDocumentArray(arr, schematype, now) {
  const timestamps = schematype.schema.options.timestamps;

  if (!timestamps) {
    return;
  }

  const len = arr.length;

  const createdAt = handleTimestampOption(timestamps, 'createdAt');
  const updatedAt = handleTimestampOption(timestamps, 'updatedAt');
  for (let i = 0; i < len; ++i) {
    if (updatedAt != null) {
      arr[i][updatedAt] = now;
    }
    if (createdAt != null) {
      arr[i][createdAt] = now;
    }

    applyTimestampsToChildren(now, arr[i], schematype.schema);
  }
}

function applyTimestampsToSingleNested(subdoc, schematype, now) {
  const timestamps = schematype.schema.options.timestamps;
  if (!timestamps) {
    return;
  }

  const createdAt = handleTimestampOption(timestamps, 'createdAt');
  const updatedAt = handleTimestampOption(timestamps, 'updatedAt');
  if (updatedAt != null) {
    subdoc[updatedAt] = now;
  }
  if (createdAt != null) {
    subdoc[createdAt] = now;
  }

  applyTimestampsToChildren(now, subdoc, schematype.schema);
}
