refactor for legibility (#5503)

* refactor for legibility

* clippy

crates/nu-command/src/database/commands/schema.rs

@@ -1,11 +1,11 @@
 use super::super::SQLiteDatabase;
-use crate::database::values::definitions::db_row::DbRow;
+use crate::database::values::definitions::{db::Db, db_row::DbRow, db_table::DbTable};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Value,
 };
-
+use rusqlite::Connection;
 #[derive(Clone)]
 pub struct SchemaDb;
 
@@ -46,25 +46,8 @@ impl Command for SchemaDb {
         let span = call.head;
 
         let sqlite_db = SQLiteDatabase::try_from_pipeline(input, span)?;
-        let conn = sqlite_db.open_connection().map_err(|e| {
-            ShellError::GenericError(
-                "Error opening file".into(),
-                e.to_string(),
-                Some(span),
-                None,
-                Vec::new(),
-            )
-        })?;
-
-        let dbs = sqlite_db.get_databases_and_tables(&conn).map_err(|e| {
-            ShellError::GenericError(
-                "Error getting databases and tables".into(),
-                e.to_string(),
-                Some(span),
-                None,
-                Vec::new(),
-            )
-        })?;
+        let conn = open_sqlite_db_connection(&sqlite_db, span)?;
+        let dbs = get_databases_and_tables(&sqlite_db, &conn, span)?;
 
         cols.push("db_filename".into());
         vals.push(Value::String {
@@ -73,115 +56,15 @@ impl Command for SchemaDb {
         });
 
         for db in dbs {
-            let tables = db.tables();
+            let tables = get_database_tables(&db);
             let mut table_list: Vec<Value> = vec![];
             let mut table_names = vec![];
             let mut table_values = vec![];
             for table in tables {
-                let columns = sqlite_db.get_columns(&conn, &table).map_err(|e| {
-                    ShellError::GenericError(
-                        "Error getting database columns".into(),
-                        e.to_string(),
-                        Some(span),
-                        None,
-                        Vec::new(),
-                    )
-                })?;
-                // a record of column name = column value
-                let mut column_info = vec![];
-                for t in columns {
-                    let mut col_names = vec![];
-                    let mut col_values = vec![];
-                    let fields = t.fields();
-                    let columns = t.columns();
-                    for (k, v) in fields.iter().zip(columns.iter()) {
-                        col_names.push(k.clone());
-                        col_values.push(Value::string(v.clone(), span));
-                    }
-                    column_info.push(Value::Record {
-                        cols: col_names.clone(),
-                        vals: col_values.clone(),
-                        span,
-                    });
-                }
-
-                let constraints = sqlite_db.get_constraints(&conn, &table).map_err(|e| {
-                    ShellError::GenericError(
-                        "Error getting DB constraints".into(),
-                        e.to_string(),
-                        Some(span),
-                        None,
-                        Vec::new(),
-                    )
-                })?;
-                let mut constraint_info = vec![];
-                for constraint in constraints {
-                    let mut con_cols = vec![];
-                    let mut con_vals = vec![];
-                    let fields = constraint.fields();
-                    let columns = constraint.columns();
-                    for (k, v) in fields.iter().zip(columns.iter()) {
-                        con_cols.push(k.clone());
-                        con_vals.push(Value::string(v.clone(), span));
-                    }
-                    constraint_info.push(Value::Record {
-                        cols: con_cols.clone(),
-                        vals: con_vals.clone(),
-                        span,
-                    });
-                }
-
-                let foreign_keys = sqlite_db.get_foreign_keys(&conn, &table).map_err(|e| {
-                    ShellError::GenericError(
-                        "Error getting DB Foreign Keys".into(),
-                        e.to_string(),
-                        Some(span),
-                        None,
-                        Vec::new(),
-                    )
-                })?;
-                let mut foreign_key_info = vec![];
-                for fk in foreign_keys {
-                    let mut fk_cols = vec![];
-                    let mut fk_vals = vec![];
-                    let fields = fk.fields();
-                    let columns = fk.columns();
-                    for (k, v) in fields.iter().zip(columns.iter()) {
-                        fk_cols.push(k.clone());
-                        fk_vals.push(Value::string(v.clone(), span));
-                    }
-                    foreign_key_info.push(Value::Record {
-                        cols: fk_cols.clone(),
-                        vals: fk_vals.clone(),
-                        span,
-                    });
-                }
-
-                let indexes = sqlite_db.get_indexes(&conn, &table).map_err(|e| {
-                    ShellError::GenericError(
-                        "Error getting DB Indexes".into(),
-                        e.to_string(),
-                        Some(span),
-                        None,
-                        Vec::new(),
-                    )
-                })?;
-                let mut index_info = vec![];
-                for index in indexes {
-                    let mut idx_cols = vec![];
-                    let mut idx_vals = vec![];
-                    let fields = index.fields();
-                    let columns = index.columns();
-                    for (k, v) in fields.iter().zip(columns.iter()) {
-                        idx_cols.push(k.clone());
-                        idx_vals.push(Value::string(v.clone(), span));
-                    }
-                    index_info.push(Value::Record {
-                        cols: idx_cols.clone(),
-                        vals: idx_vals.clone(),
-                        span,
-                    });
-                }
+                let column_info = get_table_columns(&sqlite_db, &conn, &table, span)?;
+                let constraint_info = get_table_constraints(&sqlite_db, &conn, &table, span)?;
+                let foreign_key_info = get_table_foreign_keys(&sqlite_db, &conn, &table, span)?;
+                let index_info = get_table_indexes(&sqlite_db, &conn, &table, span)?;
 
                 table_names.push(table.name);
                 table_values.push(Value::Record {
@@ -219,12 +102,15 @@ impl Command for SchemaDb {
             });
 
             cols.push("databases".into());
+
             let mut rcols = vec![];
             let mut rvals = vec![];
             rcols.push("name".into());
             rvals.push(Value::string(db.name().to_string(), span));
+
             rcols.push("tables".into());
             rvals.append(&mut table_list);
+
             vals.push(Value::Record {
                 cols: rcols,
                 vals: rvals,
@@ -238,3 +124,177 @@ impl Command for SchemaDb {
         ))
     }
 }
+
+fn open_sqlite_db_connection(db: &SQLiteDatabase, span: Span) -> Result<Connection, ShellError> {
+    db.open_connection().map_err(|e| {
+        ShellError::GenericError(
+            "Error opening file".into(),
+            e.to_string(),
+            Some(span),
+            None,
+            Vec::new(),
+        )
+    })
+}
+
+fn get_databases_and_tables(
+    db: &SQLiteDatabase,
+    conn: &Connection,
+    span: Span,
+) -> Result<Vec<Db>, ShellError> {
+    db.get_databases_and_tables(conn).map_err(|e| {
+        ShellError::GenericError(
+            "Error getting databases and tables".into(),
+            e.to_string(),
+            Some(span),
+            None,
+            Vec::new(),
+        )
+    })
+}
+
+fn get_database_tables(db: &Db) -> Vec<DbTable> {
+    db.tables()
+}
+
+fn get_table_columns(
+    db: &SQLiteDatabase,
+    conn: &Connection,
+    table: &DbTable,
+    span: Span,
+) -> Result<Vec<Value>, ShellError> {
+    let columns = db.get_columns(conn, table).map_err(|e| {
+        ShellError::GenericError(
+            "Error getting database columns".into(),
+            e.to_string(),
+            Some(span),
+            None,
+            Vec::new(),
+        )
+    })?;
+
+    // a record of column name = column value
+    let mut column_info = vec![];
+    for t in columns {
+        let mut col_names = vec![];
+        let mut col_values = vec![];
+        let fields = t.fields();
+        let columns = t.columns();
+        for (k, v) in fields.iter().zip(columns.iter()) {
+            col_names.push(k.clone());
+            col_values.push(Value::string(v.clone(), span));
+        }
+        column_info.push(Value::Record {
+            cols: col_names.clone(),
+            vals: col_values.clone(),
+            span,
+        });
+    }
+
+    Ok(column_info)
+}
+
+fn get_table_constraints(
+    db: &SQLiteDatabase,
+    conn: &Connection,
+    table: &DbTable,
+    span: Span,
+) -> Result<Vec<Value>, ShellError> {
+    let constraints = db.get_constraints(conn, table).map_err(|e| {
+        ShellError::GenericError(
+            "Error getting DB constraints".into(),
+            e.to_string(),
+            Some(span),
+            None,
+            Vec::new(),
+        )
+    })?;
+    let mut constraint_info = vec![];
+    for constraint in constraints {
+        let mut con_cols = vec![];
+        let mut con_vals = vec![];
+        let fields = constraint.fields();
+        let columns = constraint.columns();
+        for (k, v) in fields.iter().zip(columns.iter()) {
+            con_cols.push(k.clone());
+            con_vals.push(Value::string(v.clone(), span));
+        }
+        constraint_info.push(Value::Record {
+            cols: con_cols.clone(),
+            vals: con_vals.clone(),
+            span,
+        });
+    }
+
+    Ok(constraint_info)
+}
+
+fn get_table_foreign_keys(
+    db: &SQLiteDatabase,
+    conn: &Connection,
+    table: &DbTable,
+    span: Span,
+) -> Result<Vec<Value>, ShellError> {
+    let foreign_keys = db.get_foreign_keys(conn, table).map_err(|e| {
+        ShellError::GenericError(
+            "Error getting DB Foreign Keys".into(),
+            e.to_string(),
+            Some(span),
+            None,
+            Vec::new(),
+        )
+    })?;
+    let mut foreign_key_info = vec![];
+    for fk in foreign_keys {
+        let mut fk_cols = vec![];
+        let mut fk_vals = vec![];
+        let fields = fk.fields();
+        let columns = fk.columns();
+        for (k, v) in fields.iter().zip(columns.iter()) {
+            fk_cols.push(k.clone());
+            fk_vals.push(Value::string(v.clone(), span));
+        }
+        foreign_key_info.push(Value::Record {
+            cols: fk_cols.clone(),
+            vals: fk_vals.clone(),
+            span,
+        });
+    }
+
+    Ok(foreign_key_info)
+}
+
+fn get_table_indexes(
+    db: &SQLiteDatabase,
+    conn: &Connection,
+    table: &DbTable,
+    span: Span,
+) -> Result<Vec<Value>, ShellError> {
+    let indexes = db.get_indexes(conn, table).map_err(|e| {
+        ShellError::GenericError(
+            "Error getting DB Indexes".into(),
+            e.to_string(),
+            Some(span),
+            None,
+            Vec::new(),
+        )
+    })?;
+    let mut index_info = vec![];
+    for index in indexes {
+        let mut idx_cols = vec![];
+        let mut idx_vals = vec![];
+        let fields = index.fields();
+        let columns = index.columns();
+        for (k, v) in fields.iter().zip(columns.iter()) {
+            idx_cols.push(k.clone());
+            idx_vals.push(Value::string(v.clone(), span));
+        }
+        index_info.push(Value::Record {
+            cols: idx_cols.clone(),
+            vals: idx_vals.clone(),
+            span,
+        });
+    }
+
+    Ok(index_info)
+}