{
  "nodes": [
    {
      "id": "send-scheduled-customer-emails-from-sheets-cron",
      "name": "Schedule Trigger",
      "type": "n8n-nodes-base.scheduleTrigger",
      "position": [
        1350,
        1110
      ],
      "parameters": {
        "rule": {
          "interval": [
            {
              "field": "minutes",
              "minutesInterval": 1
            }
          ]
        }
      },
      "typeVersion": 1.1
    },
    {
      "id": "send-scheduled-customer-emails-from-sheets-config",
      "name": "Choose the customer messages sheet",
      "type": "n8n-nodes-base.code",
      "typeVersion": 2,
      "parameters": {
        "mode": "runOnceForAllItems",
        "jsCode": "function config(){const spreadsheetId='YOUR_SPREADSHEET_ID',sheetName='Sheet1',now=new Date();if(!sheetName.trim())throw Error('Set a worksheet name');return{spreadsheetId,sheetName,range:\"'\"+sheetName.replace(/'/g,\"''\")+\"'\",today:now.toISOString().slice(0,10).replace(/-/g,'/')};}\n\nreturn [{json:config()}];"
      }
    },
    {
      "id": "send-scheduled-customer-emails-from-sheets-read",
      "name": "Read customer messages",
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 4.2,
      "parameters": {
        "method": "GET",
        "url": "={{ \"https://sheets.googleapis.com/v4/spreadsheets/\" + encodeURIComponent($(\"Choose the customer messages sheet\").first().json.spreadsheetId) + \"/values/\" + encodeURIComponent($(\"Choose the customer messages sheet\").first().json.range) + \"?majorDimension=ROWS&valueRenderOption=FORMATTED_VALUE\" }}",
        "authentication": "predefinedCredentialType",
        "nodeCredentialType": "googleSheetsOAuth2Api",
        "options": {
          "response": {
            "response": {
              "responseFormat": "json"
            }
          }
        }
      }
    },
    {
      "id": "send-scheduled-customer-emails-from-sheets-plan",
      "name": "Find messages due today",
      "type": "n8n-nodes-base.code",
      "typeVersion": 2,
      "parameters": {
        "mode": "runOnceForAllItems",
        "jsCode": "function plan({values,today}){if(!Array.isArray(values))throw Error('Invalid sheet');if(values.length===0)return{messages:[]};const headers=values[0];if(!Array.isArray(headers))throw Error('Missing sheet headers');const names=['ID','Name','Email','Date','Status','Title','Subject'],columns={};for(const name of names){const matches=headers.flatMap((x,i)=>x===name?[i]:[]);if(matches.length!==1)throw Error('Each required header must occur exactly once');columns[name]=matches[0]}if(typeof today!=='string'||!/^\\d{4}\\/\\d\\d\\/\\d\\d$/.test(today))throw Error('Invalid current date');const ids=new Map();for(const row of values.slice(1)){if(!Array.isArray(row))throw Error('Invalid sheet row');const id=row[columns.ID];if(id!=null&&String(id)!=='')ids.set(String(id),(ids.get(String(id))??0)+1)}const messages=[];for(const row of values.slice(1)){if(row[columns.Status]!=='Waiting for sending'||row[columns.Date]!==today||!['Name','Email','Date','Title','Subject'].every(k=>row[columns[k]]!=null&&String(row[columns[k]])!==''))continue;const id=row[columns.ID];if(id==null||String(id)===''||ids.get(String(id))!==1)throw Error('Missing or duplicate message ID');messages.push(Object.fromEntries(names.map(k=>[k,String(row[columns[k]]??'')])))}return{messages};}\n\nreturn plan({values:$input.first().json.values??[],today:$(\"Choose the customer messages sheet\").first().json.today}).messages.map(x=>({json:x}));"
      }
    },
    {
      "id": "send-scheduled-customer-emails-from-sheets-loop",
      "name": "Process messages one by one",
      "type": "n8n-nodes-base.splitInBatches",
      "typeVersion": 3,
      "parameters": {
        "batchSize": 1,
        "options": {}
      }
    },
    {
      "id": "send-scheduled-customer-emails-from-sheets-gmail",
      "name": "Send a message (Gmail)",
      "type": "n8n-nodes-base.gmail",
      "position": [
        1900,
        980
      ],
      "parameters": {
        "sendTo": "={{ $json.Email }}",
        "subject": "={{ $json.Title }}",
        "message": "={{ $json.Subject }}",
        "emailType": "text",
        "options": {
          "appendAttribution": false
        }
      },
      "notesInFlow": false,
      "typeVersion": 2.1,
      "alwaysOutputData": false
    },
    {
      "id": "send-scheduled-customer-emails-from-sheets-refresh",
      "name": "Find the current message row",
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 4.2,
      "parameters": {
        "method": "GET",
        "url": "={{ \"https://sheets.googleapis.com/v4/spreadsheets/\" + encodeURIComponent($(\"Choose the customer messages sheet\").first().json.spreadsheetId) + \"/values/\" + encodeURIComponent($(\"Choose the customer messages sheet\").first().json.range) + \"?majorDimension=ROWS&valueRenderOption=FORMATTED_VALUE\" }}",
        "authentication": "predefinedCredentialType",
        "nodeCredentialType": "googleSheetsOAuth2Api",
        "options": {
          "response": {
            "response": {
              "responseFormat": "json"
            }
          }
        }
      }
    },
    {
      "id": "send-scheduled-customer-emails-from-sheets-match",
      "name": "Prepare the status cell",
      "type": "n8n-nodes-base.code",
      "typeVersion": 2,
      "parameters": {
        "mode": "runOnceForAllItems",
        "jsCode": "function match({values,current,sheetName}){if(!Array.isArray(values)||!Array.isArray(values[0])||!current||typeof current.ID!=='string')throw Error('Invalid current message');const h=values[0],fields=['ID','Name','Email','Date','Status','Title','Subject'],c={};for(const k of fields){const p=h.flatMap((x,i)=>x===k?[i]:[]);if(p.length!==1)throw Error('Missing or duplicate required header');c[k]=p[0]}const found=values.slice(1).flatMap((row,i)=>Array.isArray(row)&&String(row[c.ID]??'')===current.ID?[{row,i}]:[]);if(found.length!==1)throw Error('Message ID no longer uniquely identifies a row');const {row,i}=found[0];for(const k of fields)if(String(row[c[k]]??'')!==current[k])throw Error('Message row changed after sending');let col=c.Status+1,letters='';while(col){col--;letters=String.fromCharCode(65+col%26)+letters;col=Math.floor(col/26)}if(typeof sheetName!=='string'||!sheetName.trim())throw Error('Missing worksheet name');return{range:\"'\"+sheetName.replace(/'/g,\"''\")+\"'!\"+letters+(i+2),values:[['Sent successfully']]};}\n\nreturn [{json:match({values:$input.first().json.values??[],current:$(\"Process messages one by one\").item.json,sheetName:$(\"Choose the customer messages sheet\").first().json.sheetName})}];"
      }
    },
    {
      "id": "send-scheduled-customer-emails-from-sheets-write",
      "name": "Mark the email sent",
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 4.2,
      "parameters": {
        "method": "PUT",
        "url": "={{ \"https://sheets.googleapis.com/v4/spreadsheets/\" + encodeURIComponent($(\"Choose the customer messages sheet\").first().json.spreadsheetId) + \"/values/\" + encodeURIComponent($json.range) + \"?valueInputOption=RAW\" }}",
        "authentication": "predefinedCredentialType",
        "nodeCredentialType": "googleSheetsOAuth2Api",
        "sendBody": true,
        "specifyBody": "json",
        "jsonBody": "={{ {values:$json.values} }}",
        "options": {
          "response": {
            "response": {
              "responseFormat": "json"
            }
          }
        }
      }
    },
    {
      "id": "send-scheduled-customer-emails-from-sheets-confirm",
      "name": "Confirm the status update",
      "type": "n8n-nodes-base.code",
      "typeVersion": 2,
      "parameters": {
        "mode": "runOnceForAllItems",
        "jsCode": "function confirm({updatedCells}){if(updatedCells!==1)throw Error('Status update was not confirmed');return{ok:true};}\n\nreturn [{json:confirm({updatedCells:$input.first().json.updatedCells})}];"
      }
    }
  ],
  "pinData": {},
  "connections": {
    "Schedule Trigger": {
      "main": [
        [
          {
            "node": "Choose the customer messages sheet",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Choose the customer messages sheet": {
      "main": [
        [
          {
            "node": "Read customer messages",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Read customer messages": {
      "main": [
        [
          {
            "node": "Find messages due today",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Find messages due today": {
      "main": [
        [
          {
            "node": "Process messages one by one",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Process messages one by one": {
      "main": [
        [],
        [
          {
            "node": "Send a message (Gmail)",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Send a message (Gmail)": {
      "main": [
        [
          {
            "node": "Find the current message row",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Find the current message row": {
      "main": [
        [
          {
            "node": "Prepare the status cell",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Prepare the status cell": {
      "main": [
        [
          {
            "node": "Mark the email sent",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Mark the email sent": {
      "main": [
        [
          {
            "node": "Confirm the status update",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Confirm the status update": {
      "main": [
        [
          {
            "node": "Process messages one by one",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  },
  "name": "Send Scheduled Customer Emails from Sheets",
  "active": false,
  "settings": {
    "timezone": "UTC",
    "executionOrder": "v1"
  }
}