Preparing for github file persistence

src/backends/github/implementation.js

@@ -1,5 +1,7 @@
 import LocalForage from 'localforage';
+import MediaProxy from '../../valueObjects/MediaProxy';
 import AuthenticationPage from './AuthenticationPage';
+import { Base64 } from 'js-base64';
 
 const API_ROOT = 'https://api.github.com';
 
@@ -40,6 +42,43 @@ class API {
     });
   }
 
+  persistFiles(collection, entry, mediaFiles, options) {
+    let filename, part, parts, subtree;
+    const fileTree = {};
+    const files = [];
+
+    mediaFiles.concat(entry).forEach((file) => {
+      if (file.uploaded) { return; }
+      files.push(this.uploadBlob(file));
+      parts = file.path.split('/').filter((part) => part);
+      filename = parts.pop();
+      subtree = fileTree;
+      while (part = parts.shift()) {
+        subtree[part] = subtree[part] || {};
+        subtree = subtree[part];
+      }
+      subtree[filename] = file;
+      file.file = true;
+    });
+
+    return Promise.all(files)
+      .then(() => this.getBranch())
+      .then((branchData) => {
+        return this.updateTree(branchData.commit.sha, '/', fileTree);
+      })
+      .then((changeTree) => {
+        return this.request(`${this.repoURL}/git/commits`, {
+          type: 'POST',
+          data: JSON.stringify({ message: options.message, tree: changeTree.sha, parents: [changeTree.parentSha] })
+        });
+      }).then((response) => {
+        return this.request(`${this.repoURL}/git/refs/heads/${this.branch}`, {
+          type: 'PATCH',
+          data: JSON.stringify({ sha: response.sha })
+        });
+      });
+  }
+
   requestHeaders(headers = {}) {
     return {
       Authorization: `token ${this.token}`,
@@ -68,6 +107,78 @@ class API {
       return response.text();
     });
   }
+
+  getBranch() {
+    return this.request(`${this.repoURL}/branches/${this.branch}`);
+  }
+
+  getTree(sha) {
+    return sha ? this.request(`${this.repoURL}/git/trees/${sha}`) : Promise.resolve({ tree: [] });
+  }
+
+  toBase64(str) {
+    return Promise.resolve(
+      Base64.encode(str)
+    );
+  }
+
+  uploadBlob(item) {
+    const content = item instanceof MediaProxy ? item.toBase64() : this.toBase64(item.raw);
+
+    return content.then((contentBase64) => {
+      return this.request(`${this.repoURL}/git/blobs`, {
+        method: 'POST',
+        body: JSON.stringify({
+          content: contentBase64,
+          encoding: 'base64'
+        })
+      }).then((response) => {
+        item.sha = response.sha;
+        item.uploaded = true;
+        return item;
+      });
+    });
+  }
+
+  updateTree(sha, path, fileTree) {
+    return this.getTree(sha)
+      .then((tree) => {
+        var obj, filename, fileOrDir;
+        var updates = [];
+        var added = {};
+
+        for (var i = 0, len = tree.tree.length; i < len; i++) {
+          obj = tree.tree[i];
+          if (fileOrDir = fileTree[obj.path]) {
+            added[obj.path] = true;
+            if (fileOrDir.file) {
+              updates.push({ path: obj.path, mode: obj.mode, type: obj.type, sha: fileOrDir.sha });
+            } else {
+              updates.push(this.updateTree(obj.sha, obj.path, fileOrDir));
+            }
+          }
+        }
+        for (filename in fileTree) {
+          fileOrDir = fileTree[filename];
+          if (added[filename]) { continue; }
+          updates.push(
+            fileOrDir.file ?
+              { path: filename, mode: '100644', type: 'blob', sha: fileOrDir.sha } :
+              this.updateTree(null, filename, fileOrDir)
+          );
+        }
+        return Promise.all(updates)
+          .then((updates) => {
+            return this.request(`${this.repoURL}/git/trees`, {
+              type: 'POST',
+              data: JSON.stringify({ base_tree: sha, tree: updates })
+            });
+          }).then((response) => {
+            return { path: path, mode: '040000', type: 'tree', sha: response.sha, parentSha: sha };
+          });
+      });
+  }
+
 }
 
 export default class GitHub {
@@ -115,4 +226,8 @@ export default class GitHub {
       response.entries.filter((entry) => entry.slug === slug)[0]
     ));
   }
+
+  persistEntry(collection, entry, mediaFiles = []) {
+    return this.api.persistFiles(collection, entry, mediaFiles);
+  }
 }