From 2b55b199d6c3995450b15441237341733765e0da Mon Sep 17 00:00:00 2001
From: Palash Tyagi <23239946+Magnus167@users.noreply.github.com>
Date: Tue, 19 Nov 2024 00:32:21 +0000
Subject: [PATCH] feat: add pivot functionality for Quantamental DataFrame

---
 src/utils/qdf/mod.rs    |  1 +
 src/utils/qdf/pivots.rs | 73 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)
 create mode 100644 src/utils/qdf/pivots.rs

diff --git a/src/utils/qdf/mod.rs b/src/utils/qdf/mod.rs
index cea06c3..6e3a19f 100644
--- a/src/utils/qdf/mod.rs
+++ b/src/utils/qdf/mod.rs
@@ -2,6 +2,7 @@ pub mod core;
 pub mod update_df;
 pub mod load;
 pub mod reduce_df;
+pub mod pivots;
 // Re-export submodules for easier access
 pub use core::*;
 pub use update_df::*;
diff --git a/src/utils/qdf/pivots.rs b/src/utils/qdf/pivots.rs
new file mode 100644
index 0000000..fe148c2
--- /dev/null
+++ b/src/utils/qdf/pivots.rs
@@ -0,0 +1,73 @@
+use crate::utils::misc::*;
+use crate::utils::qdf::core::*;
+use polars::prelude::*;
+use std::collections::HashMap;
+use std::error::Error;
+
+/// The required columns for a Quantamental DataFrame.
+const QDF_INDEX_COLUMNS: [&str; 3] = ["real_date", "cid", "xcat"];
+
+/// Pivots a dataframe to a format where each ticker a column.
+pub fn pivot_dataframe_by_ticker(
+    df: DataFrame,
+    metric: Option<String>,
+) -> Result<DataFrame, Box<dyn Error>> {
+    check_quantamental_dataframe(&df)?;
+
+    // if no metric is provided, set it to 'value'
+    let mut metric = metric.unwrap_or("value".into());
+    if !df
+        .get_column_names()
+        .contains(&&PlSmallStr::from_string(metric.clone()))
+    {
+        // set metric to the first non-index column
+        metric = df.get_column_names()[3].to_string();
+    }
+
+    let mut new_df = df.clone();
+    // keep only the index columns and the metric column
+    let mut keep_cols = QDF_INDEX_COLUMNS
+        .to_vec()
+        .iter()
+        .map(|s| s.to_string())
+        .collect::<Vec<String>>();
+    keep_cols.push(metric.clone());
+
+    new_df = new_df.select(keep_cols)?;
+    // let ticker_col = get_ticker_column_for_quantamental_dataframe(&new_df)?;
+
+    // new_df.with_column(ticker_col)?;
+    // // drop the cid and xcat columns
+    // new_df = new_df.drop_many(&["cid".to_string(), "xcat".to_string()]);
+
+    // let dates_col = df.column("real_date")?;
+
+    Ok(df)
+}
+
+fn split_df_by_tickers(df: &DataFrame) -> Result<HashMap<String, DataFrame>, Box<dyn Error>> {
+    check_quantamental_dataframe(df)?;
+
+    let mut df_outs = HashMap::new();
+
+    let unique_tickers = get_unique_tickers(df)?;
+    let mut icids = Vec::new();
+    let mut ixcats = Vec::new();
+    for ticker in unique_tickers.iter() {
+        let (cid, xcat) = split_ticker(ticker.to_string())?;
+        icids.push(cid);
+        ixcats.push(xcat);
+    }
+
+    for (cid, xcat) in icids.iter().zip(ixcats.iter()) {
+        // Apply filter while borrowing df and avoid moving ownership.
+        let filter = col("cid")
+            .eq(lit(cid.clone()))
+            .and(col("xcat").eq(lit(xcat.clone())));
+
+        let df_out = df.clone().lazy().filter(filter).collect()?;
+        df_outs.insert(format!("{}_{}", cid, xcat), df_out);
+    }
+
+    Ok(df_outs)
+}