Workflow: Coffee Bot (Matrix)
Integrations: cron, function, matrix

{"id": "9", "name": "Coffee Bot (Matrix)", "nodes": [{"name": "Greetings", "type": "n8n-nodes-base.matrix", "position": [670, 240], "parameters": {"text": "\ud83d\udc4b Happy Monday Groups for this week's virtual coffee are:", "roomId": "Enter your Room ID"}, "credentials": {"matrixApi": "Matrix Creds"}, "typeVersion": 1}, {"name": "Employees in coffee chat channel", "type": "n8n-nodes-base.matrix", "position": [880, 240], "parameters": {"roomId": "Enter your Room ID", "filters": {"membership": ""}, "resource": "roomMember"}, "credentials": {"matrixApi": "Enter Your Matrix Credentials"}, "typeVersion": 1}, {"name": "Weekly trigger on monday1", "type": "n8n-nodes-base.cron", "position": [480, 240], "parameters": {"triggerTimes": {"item": [{"hour": 10, "mode": "everyWeek"}]}}, "typeVersion": 1}, {"name": "Divide into groups", "type": "n8n-nodes-base.function", "notes": "This still needs to be reconfigured to grab the information from the second Matrix node. Have an issue with the ", "position": [1090, 240], "parameters": {"functionCode": "const ideal_group_size = 3;\nlet groups = [];\nlet data_as_array = [];\nlet newItems = [];\n\n// Take all the users and add them to an array\nfor (let j = 0; j < items.length; j++) {\n  data_as_array.push({username: items[j].json.user_id});\n}\n\n// Fisher-Yates (aka Knuth) Shuffle\nfunction shuffle(array) {\n  var currentIndex = array.length, temporaryValue, randomIndex;\n\n  // While there remain elements to shuffle...\n  while (0 !== currentIndex) {\n\n    // Pick a remaining element...\n    randomIndex = Math.floor(Math.random() * currentIndex);\n    currentIndex -= 1;\n\n    // And swap it with the current element.\n    temporaryValue = array[currentIndex];\n    array[currentIndex] = array[randomIndex];\n    array[randomIndex] = temporaryValue;\n  }\n\n  return array;\n}\n\n// Randomize the sequence of names in the array\ndata_as_array = shuffle(data_as_array);\n\n// Create groups of ideal group size (3)\nfor (let i = 0; i < data_as_array.length; i += ideal_group_size) {\n  groups.push(data_as_array.slice(i, i + ideal_group_size));\n}\n\n// Make sure that no group has just one person. If it does, take\n// one from previous group and add it to that group \nfor (let k = 0; k < groups.length; k++) {\n  if (groups[k].length === 1) {\n    groups[k].push(groups[k-1].shift());\n  }\n}\n\nfor (let l = 0; l < groups.length; l++) {\n    newItems.push({json: {groupsUsername: groups[l].map(a=> a.username)}})\n}\n\nreturn newItems;\n"}, "typeVersion": 1}, {"name": "Announce groups", "type": "n8n-nodes-base.matrix", "position": [1290, 240], "parameters": {"text": "=\u2600\ufe0f {{$node[\"Divide into groups\"].json[\"groupsUsername\"].join(', ')}}", "roomId": "!hobuowPzLuKnojiyfV:matrix.org"}, "credentials": {"matrixApi": "Matrix Creds"}, "typeVersion": 1}], "active": true, "settings": {}, "connections": {"Greetings": {"main": [[{"node": "Employees in coffee chat channel", "type": "main", "index": 0}]]}, "Divide into groups": {"main": [[{"node": "Announce groups", "type": "main", "index": 0}]]}, "Weekly trigger on monday1": {"main": [[{"node": "Greetings", "type": "main", "index": 0}]]}, "Employees in coffee chat channel": {"main": [[{"node": "Divide into groups", "type": "main", "index": 0}]]}}}