dataflow_rs/engine/functions/

map.rs

use crate::engine::error::{DataflowError, Result};
use crate::engine::functions::FUNCTION_DATA_LOGIC;
use crate::engine::message::{Change, Message};
use crate::engine::AsyncFunctionHandler;
use async_trait::async_trait;
use serde_json::{json, Value};

/// A mapping function that transforms data using JSONLogic expressions.
///
/// This function allows mapping data from one location to another within
/// a message, applying transformations using JSONLogic expressions.
pub struct MapFunction {
    // No longer needs data_logic field
}

impl Default for MapFunction {
    fn default() -> Self {
        Self::new()
    }
}

impl MapFunction {
    /// Create a new MapFunction
    pub fn new() -> Self {
        Self {}
    }

    /// Set a value at the specified path within the target object
    fn set_value_at_path(&self, target: &mut Value, path: &str, value: Value) -> Result<Value> {
        let mut current = target;
        let mut old_value = Value::Null;
        let path_parts: Vec<&str> = path.split('.').collect();

        // Helper function to check if a string is a valid array index
        fn is_numeric_index(s: &str) -> bool {
            s.parse::<usize>().is_ok()
        }

        // Navigate to the parent of the target location
        for (i, part) in path_parts.iter().enumerate() {
            let is_numeric = is_numeric_index(part);

            if i == path_parts.len() - 1 {
                // We're at the last part, so set the value
                if is_numeric {
                    // Handle numeric index - ensure current is an array
                    if !current.is_array() {
                        // Convert to array if it's not already
                        *current = Value::Array(vec![]);
                    }

                    if let Ok(index) = part.parse::<usize>() {
                        if let Value::Array(arr) = current {
                            // Extend array if needed
                            while arr.len() <= index {
                                arr.push(Value::Null);
                            }
                            // Save old value
                            old_value = arr[index].clone();
                            arr[index] = value.clone();
                        }
                    } else {
                        return Err(DataflowError::Validation(format!(
                            "Invalid array index: {}",
                            part
                        )));
                    }
                } else {
                    // Handle object property
                    if !current.is_object() {
                        // Convert to object if it's not already
                        *current = Value::Object(serde_json::Map::new());
                    }

                    if let Value::Object(map) = current {
                        // Save the old value before replacing
                        old_value = map.get(*part).cloned().unwrap_or(Value::Null);
                        map.insert(part.to_string(), value.clone());
                    }
                }
            } else {
                // We need to navigate deeper
                if is_numeric {
                    // Handle numeric index - ensure current is an array
                    if !current.is_array() {
                        *current = Value::Array(vec![]);
                    }

                    if let Ok(index) = part.parse::<usize>() {
                        if let Value::Array(arr) = current {
                            // Extend array if needed
                            while arr.len() <= index {
                                arr.push(Value::Null);
                            }
                            // Ensure the indexed element exists and is ready for further navigation
                            if arr[index].is_null() {
                                // Look ahead to see if next part is numeric to decide what to create
                                let next_part = path_parts.get(i + 1).unwrap_or(&"");
                                if is_numeric_index(next_part) {
                                    arr[index] = Value::Array(vec![]);
                                } else {
                                    arr[index] = json!({});
                                }
                            }
                            current = &mut arr[index];
                        }
                    } else {
                        return Err(DataflowError::Validation(format!(
                            "Invalid array index: {}",
                            part
                        )));
                    }
                } else {
                    // Handle object property
                    if !current.is_object() {
                        *current = Value::Object(serde_json::Map::new());
                    }

                    if let Value::Object(map) = current {
                        if !map.contains_key(*part) {
                            // Look ahead to see if next part is numeric to decide what to create
                            let next_part = path_parts.get(i + 1).unwrap_or(&"");
                            if is_numeric_index(next_part) {
                                map.insert(part.to_string(), Value::Array(vec![]));
                            } else {
                                map.insert(part.to_string(), json!({}));
                            }
                        }
                        current = map.get_mut(*part).unwrap();
                    }
                }
            }
        }

        Ok(old_value)
    }
}

#[async_trait]
impl AsyncFunctionHandler for MapFunction {
    async fn execute(&self, message: &mut Message, input: &Value) -> Result<(usize, Vec<Change>)> {
        // Extract mappings array from input
        let mappings = input.get("mappings").ok_or_else(|| {
            DataflowError::Validation("Missing 'mappings' array in input".to_string())
        })?;

        let mappings_arr = mappings
            .as_array()
            .ok_or_else(|| DataflowError::Validation("'mappings' must be an array".to_string()))?;

        let mut changes = Vec::new();

        // Process each mapping
        for mapping in mappings_arr {
            // Get path where to store the result
            let target_path = mapping.get("path").and_then(Value::as_str).ok_or_else(|| {
                DataflowError::Validation("Missing 'path' in mapping".to_string())
            })?;

            // Get the logic to evaluate
            let logic = mapping.get("logic").ok_or_else(|| {
                DataflowError::Validation("Missing 'logic' in mapping".to_string())
            })?;

            // Clone message data for evaluation context
            let data_clone = message.data.clone();
            let metadata_clone = message.metadata.clone();
            let temp_data_clone = message.temp_data.clone();

            // Create a combined data object with message fields for evaluation
            let data_for_eval = json!({
                "data": data_clone,
                "metadata": metadata_clone,
                "temp_data": temp_data_clone,
            });

            // Determine target object based on path prefix
            let (target_object, adjusted_path) =
                if let Some(path) = target_path.strip_prefix("data.") {
                    (&mut message.data, path)
                } else if let Some(path) = target_path.strip_prefix("metadata.") {
                    (&mut message.metadata, path)
                } else if let Some(path) = target_path.strip_prefix("temp_data.") {
                    (&mut message.temp_data, path)
                } else if target_path == "data" {
                    (&mut message.data, "")
                } else if target_path == "metadata" {
                    (&mut message.metadata, "")
                } else if target_path == "temp_data" {
                    (&mut message.temp_data, "")
                } else {
                    // Default to data
                    (&mut message.data, target_path)
                };

            // Evaluate the logic using thread-local DataLogic
            let result = FUNCTION_DATA_LOGIC.with(|data_logic_cell| {
                let mut data_logic = data_logic_cell.borrow_mut();
                data_logic.reset_arena();

                data_logic
                    .evaluate_json(logic, &data_for_eval, None)
                    .map_err(|e| {
                        DataflowError::LogicEvaluation(format!("Failed to evaluate logic: {}", e))
                    })
            })?;

            // Set the result at the target path
            if adjusted_path.is_empty() {
                // Replace the entire object
                let old_value = std::mem::replace(target_object, result.clone());
                changes.push(Change {
                    path: target_path.to_string(),
                    old_value,
                    new_value: result,
                });
            } else {
                // Set a specific path
                let old_value =
                    self.set_value_at_path(target_object, adjusted_path, result.clone())?;
                changes.push(Change {
                    path: target_path.to_string(),
                    old_value,
                    new_value: result,
                });
            }
        }

        Ok((200, changes))
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::engine::message::Message;
    use serde_json::json;

    #[tokio::test]
    async fn test_array_notation_simple() {
        let map_fn = MapFunction::new();

        // Test simple array notation: data.items.0.name
        let mut message = Message::new(&json!({}));
        message.data = json!({});

        let input = json!({
            "mappings": [
                {
                    "path": "data.items.0.name",
                    "logic": "Test Item"
                }
            ]
        });

        let result = map_fn.execute(&mut message, &input).await;

        assert!(result.is_ok());
        let expected = json!({
            "items": [
                {
                    "name": "Test Item"
                }
            ]
        });
        assert_eq!(message.data, expected);
    }

    #[tokio::test]
    async fn test_array_notation_complex_path() {
        let map_fn = MapFunction::new();

        // Test complex path like the original example: data.MX.FIToFICstmrCdtTrf.CdtTrfTxInf.0.PmtId.InstrId
        let mut message = Message::new(&json!({}));
        message.data = json!({});

        let input = json!({
            "mappings": [
                {
                    "path": "data.MX.FIToFICstmrCdtTrf.CdtTrfTxInf.0.PmtId.InstrId",
                    "logic": "INSTR123"
                }
            ]
        });

        let result = map_fn.execute(&mut message, &input).await;

        assert!(result.is_ok());
        let expected = json!({
            "MX": {
                "FIToFICstmrCdtTrf": {
                    "CdtTrfTxInf": [
                        {
                            "PmtId": {
                                "InstrId": "INSTR123"
                            }
                        }
                    ]
                }
            }
        });
        assert_eq!(message.data, expected);
    }

    #[tokio::test]
    async fn test_multiple_array_indices() {
        let map_fn = MapFunction::new();

        // Test multiple array indices in the same path: data.matrix.0.1.value
        let mut message = Message::new(&json!({}));
        message.data = json!({});

        let input = json!({
            "mappings": [
                {
                    "path": "data.matrix.0.1.value",
                    "logic": "cell_01"
                },
                {
                    "path": "data.matrix.1.0.value",
                    "logic": "cell_10"
                }
            ]
        });

        let result = map_fn.execute(&mut message, &input).await;

        assert!(result.is_ok());
        let expected = json!({
            "matrix": [
                [
                    null,
                    {
                        "value": "cell_01"
                    }
                ],
                [
                    {
                        "value": "cell_10"
                    }
                ]
            ]
        });
        assert_eq!(message.data, expected);
    }

    #[tokio::test]
    async fn test_array_extension() {
        let map_fn = MapFunction::new();

        // Test that arrays are extended when accessing high indices
        let mut message = Message::new(&json!({}));
        message.data = json!({});

        let input = json!({
            "mappings": [
                {
                    "path": "data.items.5.name",
                    "logic": "Item at index 5"
                }
            ]
        });

        let result = map_fn.execute(&mut message, &input).await;

        assert!(result.is_ok());

        // Should create an array with 6 elements (indices 0-5)
        assert!(message.data["items"].is_array());
        let items_array = message.data["items"].as_array().unwrap();
        assert_eq!(items_array.len(), 6);

        // First 5 elements should be null
        for i in 0..5 {
            assert_eq!(items_array[i], json!(null));
        }

        // Element at index 5 should have our value
        assert_eq!(items_array[5], json!({"name": "Item at index 5"}));
    }

    #[tokio::test]
    async fn test_mixed_array_and_object_notation() {
        let map_fn = MapFunction::new();

        // Test mixing array and object notation: data.users.0.profile.addresses.1.city
        let mut message = Message::new(&json!({}));
        message.data = json!({});

        let input = json!({
            "mappings": [
                {
                    "path": "data.users.0.profile.addresses.1.city",
                    "logic": "New York"
                },
                {
                    "path": "data.users.0.profile.name",
                    "logic": "John Doe"
                }
            ]
        });

        let result = map_fn.execute(&mut message, &input).await;

        assert!(result.is_ok());
        let expected = json!({
            "users": [
                {
                    "profile": {
                        "name": "John Doe",
                        "addresses": [
                            null,
                            {
                                "city": "New York"
                            }
                        ]
                    }
                }
            ]
        });
        assert_eq!(message.data, expected);
    }

    #[tokio::test]
    async fn test_overwrite_existing_value() {
        let map_fn = MapFunction::new();

        // Test overwriting an existing value in an array
        let mut message = Message::new(&json!({}));
        message.data = json!({
            "items": [
                {"name": "Old Value"},
                {"name": "Another Item"}
            ]
        });

        let input = json!({
            "mappings": [
                {
                    "path": "data.items.0.name",
                    "logic": "New Value"
                }
            ]
        });

        let result = map_fn.execute(&mut message, &input).await;

        assert!(result.is_ok());
        let expected = json!({
            "items": [
                {"name": "New Value"},
                {"name": "Another Item"}
            ]
        });
        assert_eq!(message.data, expected);

        // Check that changes are recorded
        let (_, changes) = result.unwrap();
        assert_eq!(changes.len(), 1);
        assert_eq!(changes[0].path, "data.items.0.name");
        assert_eq!(changes[0].old_value, json!("Old Value"));
        assert_eq!(changes[0].new_value, json!("New Value"));
    }

    #[tokio::test]
    async fn test_array_notation_with_jsonlogic() {
        let map_fn = MapFunction::new();

        // Test array notation with JSONLogic expressions
        let mut message = Message::new(&json!({}));
        message.temp_data = json!({
            "transactions": [
                {"id": "tx1", "amount": 100},
                {"id": "tx2", "amount": 200}
            ]
        });
        message.data = json!({});

        let input = json!({
            "mappings": [
                {
                    "path": "data.processed.0.transaction_id",
                    "logic": {"var": "temp_data.transactions.0.id"}
                },
                {
                    "path": "data.processed.0.amount_cents",
                    "logic": {"*": [{"var": "temp_data.transactions.0.amount"}, 100]}
                }
            ]
        });

        let result = map_fn.execute(&mut message, &input).await;

        assert!(result.is_ok());
        let expected = json!({
            "processed": [
                {
                    "transaction_id": "tx1",
                    "amount_cents": 10000
                }
            ]
        });
        assert_eq!(message.data, expected);
    }

    #[tokio::test]
    async fn test_convert_object_to_array() {
        let map_fn = MapFunction::new();

        // Test converting an existing object to an array when numeric index is encountered
        let mut message = Message::new(&json!({}));
        message.data = json!({
            "items": {
                "existing_key": "existing_value"
            }
        });

        let input = json!({
            "mappings": [
                {
                    "path": "data.items.0.new_value",
                    "logic": "array_item"
                }
            ]
        });

        let result = map_fn.execute(&mut message, &input).await;

        assert!(result.is_ok());
        // The object should be converted to an array
        assert!(message.data["items"].is_array());
        let expected = json!({
            "items": [
                {
                    "new_value": "array_item"
                }
            ]
        });
        assert_eq!(message.data, expected);
    }

    #[tokio::test]
    async fn test_non_numeric_index_handling() {
        let map_fn = MapFunction::new();

        // Test that non-numeric strings are treated as object keys, not array indices
        let mut message = Message::new(&json!({}));
        message.data = json!({});

        let input = json!({
            "mappings": [
                {
                    "path": "data.items.invalid_index.name",
                    "logic": "test"
                }
            ]
        });

        let result = map_fn.execute(&mut message, &input).await;

        // This should succeed and create an object structure
        assert!(result.is_ok());
        let expected = json!({
            "items": {
                "invalid_index": {
                    "name": "test"
                }
            }
        });
        assert_eq!(message.data, expected);

        // Verify that "invalid_index" was treated as an object key, not array index
        assert!(message.data["items"].is_object());
        assert!(!message.data["items"].is_array());
    }
}