2 files changed, 102 insertions, 0 deletions

diff --git a/server/models/shared/index.ts b/server/models/shared/index.ts
index 5b97510e0..802404555 100644
--- a/server/models/shared/index.ts
+++ b/server/models/shared/index.ts
@@ -1,2 +1,3 @@
+export * from './model-builder'
 export * from './query'
 export * from './update'
diff --git a/server/models/shared/model-builder.ts b/server/models/shared/model-builder.ts
new file mode 100644
index 000000000..c015ca4f5
--- /dev/null
+++ b/server/models/shared/model-builder.ts
@@ -0,0 +1,101 @@
+import { isPlainObject } from 'lodash'
+import { Model as SequelizeModel, Sequelize } from 'sequelize'
+import { logger } from '@server/helpers/logger'
+
+export class ModelBuilder <T extends SequelizeModel> {
+  private readonly modelRegistry = new Map<string, T>()
+
+  constructor (private readonly sequelize: Sequelize) {
+
+  }
+
+  createModels (jsonArray: any[], baseModelName: string): T[] {
+    const result: T[] = []
+
+    for (const json of jsonArray) {
+      const { created, model } = this.createModel(json, baseModelName, json.id + '.' + baseModelName)
+
+      if (created) result.push(model)
+    }
+
+    return result
+  }
+
+  private createModel (json: any, modelName: string, keyPath: string) {
+    if (!json.id) return { created: false, model: null }
+
+    const { created, model } = this.createOrFindModel(json, modelName, keyPath)
+
+    for (const key of Object.keys(json)) {
+      const value = json[key]
+      if (!value) continue
+
+      // Child model
+      if (isPlainObject(value)) {
+        const { created, model: subModel } = this.createModel(value, key, keyPath + '.' + json.id + '.' + key)
+        if (!created || !subModel) continue
+
+        const Model = this.findModelBuilder(modelName)
+        const association = Model.associations[key]
+
+        if (!association) {
+          logger.error('Cannot find association %s of model %s', key, modelName, { associations: Object.keys(Model.associations) })
+          continue
+        }
+
+        if (association.isMultiAssociation) {
+          if (!Array.isArray(model[key])) model[key] = []
+
+          model[key].push(subModel)
+        } else {
+          model[key] = subModel
+        }
+      }
+    }
+
+    return { created, model }
+  }
+
+  private createOrFindModel (json: any, modelName: string, keyPath: string) {
+    const registryKey = this.getModelRegistryKey(json, keyPath)
+    if (this.modelRegistry.has(registryKey)) {
+      return {
+        created: false,
+        model: this.modelRegistry.get(registryKey)
+      }
+    }
+
+    const Model = this.findModelBuilder(modelName)
+
+    if (!Model) {
+      logger.error(
+        'Cannot build model %s that does not exist', this.buildSequelizeModelName(modelName),
+        { existing: this.sequelize.modelManager.all.map(m => m.name) }
+      )
+      return undefined
+    }
+
+    // FIXME: typings
+    const model = new (Model as any)(json)
+    this.modelRegistry.set(registryKey, model)
+
+    return { created: true, model }
+  }
+
+  private findModelBuilder (modelName: string) {
+    return this.sequelize.modelManager.getModel(this.buildSequelizeModelName(modelName))
+  }
+
+  private buildSequelizeModelName (modelName: string) {
+    if (modelName === 'Avatars') return 'ActorImageModel'
+    if (modelName === 'ActorFollowing') return 'ActorModel'
+    if (modelName === 'ActorFollower') return 'ActorModel'
+    if (modelName === 'FlaggedAccount') return 'AccountModel'
+
+    return modelName + 'Model'
+  }
+
+  private getModelRegistryKey (json: any, keyPath: string) {
+    return keyPath + json.id
+  }
+}