// Rust-oracle - Rust binding for Oracle database
//
// URL: https://github.com/kubo/rust-oracle
//
//-----------------------------------------------------------------------------
// Copyright (c) 2017-2018 Kubo Takehiro <kubo@jiubao.org>. All rights reserved.
// This program is free software: you can modify it and/or redistribute it
// under the terms of:
//
// (i)  the Universal Permissive License v 1.0 or at your option, any
//      later version (http://oss.oracle.com/licenses/upl); and/or
//
// (ii) the Apache License v 2.0. (http://www.apache.org/licenses/LICENSE-2.0)
//-----------------------------------------------------------------------------

use std::cmp;
use std::fmt;
use std::ptr;
use std::sync::Arc;

use crate::binding::*;
use crate::chkerr;
use crate::sql_type::FromSql;
use crate::sql_type::OracleType;
use crate::sql_type::ToSql;
use crate::to_rust_str;
use crate::util::write_literal;
use crate::Connection;
use crate::Context;
use crate::DpiObjectAttr;
use crate::DpiObjectType;
use crate::Error;
use crate::Result;
use crate::SqlValue;

unsafe fn release_dpi_data(data: &dpiData, native_type_num: u32) {
    if data.isNull == 0 {
        match native_type_num {
            DPI_NATIVE_TYPE_LOB => {
                dpiLob_release(data.value.asLOB);
            }
            DPI_NATIVE_TYPE_OBJECT => {
                dpiObject_release(data.value.asObject);
            }
            DPI_NATIVE_TYPE_ROWID => {
                dpiRowid_release(data.value.asRowid);
            }
            _ => (),
        }
    }
}

/// Oracle-specific collection data type
///
/// This type corresponds to varray and nested table data types.
/// See [Oracle manual](https://docs.oracle.com/database/122/ADOBJ/collection-data-types.htm).
///
/// ```no_run
/// # use oracle::*; fn try_main() -> Result<()> {
/// let conn = Connection::connect("scott", "tiger", "")?;
///
/// // MDSYS.SDO_ELEM_INFO_ARRAY is defined as VARRAY (1048576) of NUMBER.
/// let objtype = conn.object_type("MDSYS.SDO_ELEM_INFO_ARRAY")?;
///
/// // Create a new collection
/// let mut obj = objtype.new_collection()?;
/// obj.push(&1);
/// obj.push(&3);
/// assert_eq!(obj.to_string(), "MDSYS.SDO_ELEM_INFO_ARRAY(1, 3)");
/// # Ok(())} fn main() { try_main().unwrap(); }
/// ```
///
/// Note: Methods in the type may be changed in future.
pub struct Collection {
    ctxt: &'static Context,
    pub(crate) handle: *mut dpiObject,
    objtype: ObjectType,
}

impl Collection {
    pub(crate) fn new(
        ctxt: &'static Context,
        handle: *mut dpiObject,
        objtype: ObjectType,
    ) -> Collection {
        Collection {
            ctxt: ctxt,
            handle: handle,
            objtype: objtype,
        }
    }

    /// Returns type information.
    pub fn object_type(&self) -> &ObjectType {
        &self.objtype
    }

    /// Returns the number of elements.
    ///
    /// This counts also deleted elements. See "Comments" about [OCICollSize()][].
    ///
    /// [OCICollSize()]: https://docs.oracle.com/en/database/oracle/oracle-database/12.2/lnoci/oci-collection-and-iterator-functions.html#GUID-B8F6665F-12F1-43DB-A27E-82A2A655D701
    pub fn size(&self) -> Result<i32> {
        let mut size = 0;
        chkerr!(self.ctxt, dpiObject_getSize(self.handle, &mut size));
        Ok(size)
    }

    /// Returns the first index.
    ///
    /// Use this method if indexes of the collection isn't continuous.
    pub fn first_index(&self) -> Result<i32> {
        let mut index = 0;
        let mut exists = 0;
        chkerr!(
            self.ctxt,
            dpiObject_getFirstIndex(self.handle, &mut index, &mut exists)
        );
        if exists != 0 {
            Ok(index)
        } else {
            Err(Error::NoDataFound)
        }
    }

    /// Returns the last index.
    ///
    /// Use this method if indexes of the collection isn't continuous.
    pub fn last_index(&self) -> Result<i32> {
        let mut index = 0;
        let mut exists = 0;
        chkerr!(
            self.ctxt,
            dpiObject_getLastIndex(self.handle, &mut index, &mut exists)
        );
        if exists != 0 {
            Ok(index)
        } else {
            Err(Error::NoDataFound)
        }
    }

    /// Returns the next index following the specified index.
    ///
    /// Use this method if indexes of the collection isn't continuous.
    pub fn next_index(&self, index: i32) -> Result<i32> {
        let mut next = 0;
        let mut exists = 0;
        chkerr!(
            self.ctxt,
            dpiObject_getNextIndex(self.handle, index, &mut next, &mut exists)
        );
        if exists != 0 {
            Ok(next)
        } else {
            Err(Error::NoDataFound)
        }
    }

    /// Returns the previous index following the specified index.
    ///
    /// Use this method if indexes of the collection isn't continuous.
    pub fn prev_index(&self, index: i32) -> Result<i32> {
        let mut prev = 0;
        let mut exists = 0;
        chkerr!(
            self.ctxt,
            dpiObject_getPrevIndex(self.handle, index, &mut prev, &mut exists)
        );
        if exists != 0 {
            Ok(prev)
        } else {
            Err(Error::NoDataFound)
        }
    }

    /// Returns whether an element exists at the specified index.
    pub fn exist(&self, index: i32) -> Result<bool> {
        let mut exists = 0;
        chkerr!(
            self.ctxt,
            dpiObject_getElementExistsByIndex(self.handle, index, &mut exists)
        );
        Ok(exists != 0)
    }

    /// Returns the value of the element at the specified index.
    pub fn get<T>(&self, index: i32) -> Result<T>
    where
        T: FromSql,
    {
        let oratype = self.objtype.element_oracle_type().unwrap();
        let mut data = Default::default();
        let mut buf = [0i8; 172]; // DPI_NUMBER_AS_TEXT_CHARS in odpi/src/dpiImpl.h
        if let OracleType::Number(_, _) = *oratype {
            unsafe {
                dpiData_setBytes(&mut data, buf.as_mut_ptr(), buf.len() as u32);
            }
        }
        let sql_value = SqlValue::from_oratype(self.ctxt, oratype, &mut data)?;
        let native_type_num = sql_value.native_type_num();
        chkerr!(
            self.ctxt,
            dpiObject_getElementValueByIndex(self.handle, index, native_type_num, &mut data)
        );
        let res = sql_value.get();
        unsafe { release_dpi_data(&data, native_type_num) };
        res
    }

    /// Sets the value to the element at the specified index.
    pub fn set(&mut self, index: i32, value: &dyn ToSql) -> Result<()> {
        let oratype = self.objtype.element_oracle_type().unwrap();
        let mut data = Default::default();
        let mut sql_value = SqlValue::from_oratype(self.ctxt, oratype, &mut data)?;
        sql_value.set(value)?;
        chkerr!(
            self.ctxt,
            dpiObject_setElementValueByIndex(
                self.handle,
                index,
                sql_value.native_type_num(),
                &mut data
            )
        );
        Ok(())
    }

    /// Appends an element to the end of the collection.
    pub fn push(&mut self, value: &dyn ToSql) -> Result<()> {
        let oratype = self.objtype.element_oracle_type().unwrap();
        let mut data = Default::default();
        let mut sql_value = SqlValue::from_oratype(self.ctxt, oratype, &mut data)?;
        sql_value.set(value)?;
        chkerr!(
            self.ctxt,
            dpiObject_appendElement(self.handle, sql_value.native_type_num(), &mut data)
        );
        Ok(())
    }

    /// Remove the element at the specified index.
    /// Note that the position ordinals of the remaining elements are not changed.
    /// The operation creates **holes** in the collection.
    pub fn remove(&mut self, index: i32) -> Result<()> {
        chkerr!(
            self.ctxt,
            dpiObject_deleteElementByIndex(self.handle, index)
        );
        Ok(())
    }

    /// Trims a number of elements from the end of a collection.
    ///
    /// If the number of of elements to trim exceeds the current size
    /// of the collection an error is returned.
    pub fn trim(&mut self, len: usize) -> Result<()> {
        chkerr!(self.ctxt, dpiObject_trim(self.handle, len as u32));
        Ok(())
    }
}

impl Clone for Collection {
    fn clone(&self) -> Collection {
        unsafe { dpiObject_addRef(self.handle) };
        Collection::new(self.ctxt, self.handle, self.objtype.clone())
    }
}

impl Drop for Collection {
    fn drop(&mut self) {
        let _ = unsafe { dpiObject_release(self.handle) };
    }
}

impl FromSql for Collection {
    fn from_sql(val: &SqlValue) -> Result<Collection> {
        val.to_collection()
    }
}

impl ToSql for Collection {
    fn oratype(&self, _conn: &Connection) -> Result<OracleType> {
        Ok(OracleType::Object(self.object_type().clone()))
    }
    fn to_sql(&self, val: &mut SqlValue) -> Result<()> {
        val.set_collection(self)
    }
}

impl fmt::Display for Collection {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}(", self.objtype)?;
        if let Ok(index) = self.first_index() {
            let mut idx = index;
            let oratype = self.objtype.element_oracle_type().unwrap();
            loop {
                write_literal(f, &self.get(idx), oratype)?;
                if let Ok(index) = self.next_index(idx) {
                    idx = index;
                    write!(f, ", ")?;
                } else {
                    break;
                }
            }
        }
        write!(f, ")")
    }
}

impl fmt::Debug for Collection {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        let oratype = self.objtype.element_oracle_type().unwrap();
        write!(f, "Collection({} collection of {}: ", self.objtype, oratype)?;
        if let Ok(index) = self.first_index() {
            let mut idx = index;
            loop {
                write_literal(f, &self.get(idx), oratype)?;
                if let Ok(index) = self.next_index(idx) {
                    idx = index;
                    write!(f, ", ")?;
                } else {
                    break;
                }
            }
        }
        write!(f, ")")
    }
}

/// Oracle-specific object data type
///
/// ```no_run
/// # use oracle::*; fn try_main() -> Result<()> {
/// let conn = Connection::connect("scott", "tiger", "")?;
///
/// // MDSYS.SDO_GEOMETRY
/// // https://docs.oracle.com/en/database/oracle/oracle-database/12.2/spatl/spatial-datatypes-metadata.html#GUID-683FF8C5-A773-4018-932D-2AF6EC8BC119
/// let geom_type = conn.object_type("MDSYS.SDO_GEOMETRY")?;
/// let point_type = conn.object_type("MDSYS.SDO_POINT_TYPE")?;
///
/// // Create a new object
/// let mut obj = geom_type.new_object()?;
/// let mut point = point_type.new_object()?;
/// point.set("X", &-79)?;
/// point.set("Y", &37)?;
/// obj.set("SDO_GTYPE", &2001)?;
/// obj.set("SDO_POINT", &point)?;
/// assert_eq!(obj.to_string(), "MDSYS.SDO_GEOMETRY(2001, NULL, MDSYS.SDO_POINT_TYPE(-79, 37, NULL), NULL, NULL)");
///
/// // Gets an attribute value.
/// let gtype: i32 = obj.get("SDO_GTYPE")?;
/// assert_eq!(gtype, 2001);
/// # Ok(())} fn main() { try_main().unwrap(); }
/// ```
///
/// Note: Methods in the type may be changed in future.
pub struct Object {
    ctxt: &'static Context,
    pub(crate) handle: *mut dpiObject,
    objtype: ObjectType,
}

impl Object {
    pub(crate) fn new(
        ctxt: &'static Context,
        handle: *mut dpiObject,
        objtype: ObjectType,
    ) -> Object {
        Object {
            ctxt: ctxt,
            handle: handle,
            objtype: objtype,
        }
    }

    /// Returns type information.
    pub fn object_type(&self) -> &ObjectType {
        &self.objtype
    }

    fn type_attr(&self, name: &str) -> Result<&ObjectTypeAttr> {
        for attr in self.objtype.attributes() {
            if attr.name() == name {
                return Ok(attr);
            }
        }
        Err(Error::InvalidAttributeName(name.to_string()))
    }

    pub(crate) fn get_by_attr<T>(&self, attr: &ObjectTypeAttr) -> Result<T>
    where
        T: FromSql,
    {
        let mut data = Default::default();
        let mut buf = [0i8; 172]; // DPI_NUMBER_AS_TEXT_CHARS in odpi/src/dpiImpl.h
        if let OracleType::Number(_, _) = attr.oratype {
            unsafe {
                dpiData_setBytes(&mut data, buf.as_mut_ptr(), buf.len() as u32);
            }
        }
        let sql_value = SqlValue::from_oratype(self.ctxt, &attr.oratype, &mut data)?;
        let native_type_num = sql_value.native_type_num();
        chkerr!(
            self.ctxt,
            dpiObject_getAttributeValue(self.handle, attr.handle.raw(), native_type_num, &mut data)
        );
        let res = sql_value.get();
        unsafe { release_dpi_data(&data, native_type_num) };
        res
    }

    /// Gets an value at the specified attribute.
    pub fn get<T>(&self, name: &str) -> Result<T>
    where
        T: FromSql,
    {
        self.get_by_attr(self.type_attr(name)?)
    }

    /// Sets the value to the specified attribute.
    pub fn set(&mut self, name: &str, value: &dyn ToSql) -> Result<()> {
        let attrtype = self.type_attr(name)?;
        let mut data = Default::default();
        let mut sql_value = SqlValue::from_oratype(self.ctxt, &attrtype.oratype, &mut data)?;
        sql_value.set(value)?;
        chkerr!(
            self.ctxt,
            dpiObject_setAttributeValue(
                self.handle,
                attrtype.handle.raw(),
                sql_value.native_type_num(),
                &mut data
            )
        );
        Ok(())
    }
}

impl Clone for Object {
    fn clone(&self) -> Object {
        unsafe { dpiObject_addRef(self.handle) };
        Object::new(self.ctxt, self.handle, self.objtype.clone())
    }
}

impl Drop for Object {
    fn drop(&mut self) {
        let _ = unsafe { dpiObject_release(self.handle) };
    }
}

impl FromSql for Object {
    fn from_sql(val: &SqlValue) -> Result<Object> {
        val.to_object()
    }
}

impl ToSql for Object {
    fn oratype(&self, _conn: &Connection) -> Result<OracleType> {
        Ok(OracleType::Object(self.object_type().clone()))
    }
    fn to_sql(&self, val: &mut SqlValue) -> Result<()> {
        val.set_object(self)
    }
}

impl fmt::Display for Object {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}(", self.objtype)?;
        let mut first = true;
        for attr in self.objtype.attributes() {
            if first {
                first = false;
            } else {
                write!(f, ", ")?;
            }
            write_literal(f, &self.get_by_attr(attr), &attr.oratype)?;
        }
        write!(f, ")")
    }
}

impl fmt::Debug for Object {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "Object({}(", self.objtype)?;
        let mut first = true;
        for attr in self.objtype.attributes() {
            if first {
                first = false;
            } else {
                write!(f, ", ")?;
            }
            write!(f, "{}({}): ", attr.name(), attr.oracle_type())?;
            write_literal(f, &self.get_by_attr(attr), &attr.oratype)?;
        }
        write!(f, "))")
    }
}

/// Type information about Object or Collection data type
///
/// This is for not only Object type information but also
/// collection type information.
///
/// # Examples
///
/// Gets MDSYS.SDO_GEOMETRY object type information.
///
/// ```no_run
/// # use oracle::*; fn try_main() -> Result<()> {
/// let conn = Connection::connect("scott", "tiger", "")?;
/// let objtype = conn.object_type("MDSYS.SDO_GEOMETRY");
/// # Ok(())} fn main() { try_main().unwrap(); }
/// ```
///
/// Gets object type infomration in query.
///
/// ```no_run
/// # use oracle::*; use oracle::sql_type::*; fn try_main() -> Result<()> {
/// let conn = Connection::connect("scott", "tiger", "")?;
/// // conn.execute("create table location (name varchar2(60), loc sdo_geometry)", &[]);
/// let mut stmt = conn.prepare("select loc from location where name = '...'", &[])?;
/// let rows = stmt.query(&[])?;
/// let objtype = if let OracleType::Object(ref objtype) = *rows.column_info()[0].oracle_type() {
///     objtype
/// } else {
///     panic!("Not an object type")
/// };
/// # Ok(())} fn main() { try_main().unwrap(); }
/// ```
#[derive(Clone)]
pub struct ObjectType {
    pub(crate) internal: Arc<ObjectTypeInternal>,
}

impl ObjectType {
    pub(crate) fn from_dpi_object_type(
        ctxt: &'static Context,
        handle: DpiObjectType,
    ) -> Result<ObjectType> {
        Ok(ObjectType {
            internal: Arc::new(ObjectTypeInternal::from_dpi_object_type(ctxt, handle)?),
        })
    }

    pub(crate) fn handle(&self) -> &DpiObjectType {
        &self.internal.handle
    }

    /// Gets schema name
    pub fn schema(&self) -> &str {
        &self.internal.schema
    }

    /// Gets object name
    pub fn name(&self) -> &str {
        &self.internal.name
    }

    /// True when it is a collectoin. Otherwise false.
    pub fn is_collection(&self) -> bool {
        self.internal.elem_oratype.is_some()
    }

    /// Gets the Oracle type of elements if it is a collection.
    /// Otherwise, `None`.
    pub fn element_oracle_type(&self) -> Option<&OracleType> {
        if let Some(ref oratype) = self.internal.elem_oratype {
            Some(oratype)
        } else {
            None
        }
    }

    /// Gets the number of attributes if it isn't a collection.
    /// Otherwise, 0.
    pub fn num_attributes(&self) -> usize {
        self.internal.attrs.len()
    }

    /// Gets a vector of attribute information if it isn't a collection.
    /// Otherwise, a zero-length vector.
    ///
    /// # Examples
    ///
    /// Prints attribute information of `MDSYS.SDO_GEOMETRY`.
    ///
    /// ```no_run
    /// # use oracle::*; fn try_main() -> Result<()> {
    /// let conn = Connection::connect("scott", "tiger", "")?;
    /// let objtype = conn.object_type("MDSYS.SDO_GEOMETRY")?;
    /// for attr in objtype.attributes() {
    ///     println!("{:-20} {}", attr.name(), attr.oracle_type());
    /// }
    /// # Ok(())} fn main() { try_main().unwrap(); }
    /// ```
    pub fn attributes(&self) -> &[ObjectTypeAttr] {
        &self.internal.attrs
    }

    /// Create a new Oracle object.
    pub fn new_object(&self) -> Result<Object> {
        if self.is_collection() {
            return Err(Error::InvalidOperation(format!(
                "{}.{} isn't object type.",
                self.schema(),
                self.name()
            )));
        }
        let ctxt = self.internal.ctxt;
        let mut handle = ptr::null_mut();
        chkerr!(
            ctxt,
            dpiObjectType_createObject(self.internal.handle.raw(), &mut handle)
        );
        Ok(Object::new(ctxt, handle, self.clone()))
    }

    /// Create a new collection.
    pub fn new_collection(&self) -> Result<Collection> {
        if !self.is_collection() {
            return Err(Error::InvalidOperation(format!(
                "{}.{} isn't collection type.",
                self.schema(),
                self.name()
            )));
        }
        let ctxt = self.internal.ctxt;
        let mut handle = ptr::null_mut();
        chkerr!(
            ctxt,
            dpiObjectType_createObject(self.internal.handle.raw(), &mut handle)
        );
        Ok(Collection::new(ctxt, handle, self.clone()))
    }
}

impl cmp::PartialEq for ObjectType {
    fn eq(&self, other: &Self) -> bool {
        self.internal == other.internal
    }
}

impl fmt::Display for ObjectType {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", self.internal)
    }
}

impl fmt::Debug for ObjectType {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{:?}", self.internal)
    }
}

/// Object type attribute information
///
/// See [ObjectType.attributes()](struct.ObjectType.html#method.attributes)
pub struct ObjectTypeAttr {
    ctxt: &'static Context,
    handle: DpiObjectAttr,
    name: String,
    oratype: OracleType,
}

impl ObjectTypeAttr {
    fn new(ctxt: &'static Context, handle: DpiObjectAttr) -> Result<ObjectTypeAttr> {
        let mut info = Default::default();
        chkerr!(ctxt, dpiObjectAttr_getInfo(handle.raw(), &mut info));
        Ok(ObjectTypeAttr {
            ctxt: ctxt,
            handle: handle,
            name: to_rust_str(info.name, info.nameLength),
            oratype: OracleType::from_type_info(ctxt, &info.typeInfo)?,
        })
    }

    /// Gets the attribute name
    pub fn name(&self) -> &str {
        &self.name
    }

    /// Gets the attribute type
    pub fn oracle_type(&self) -> &OracleType {
        &self.oratype
    }
}

impl Clone for ObjectTypeAttr {
    fn clone(&self) -> ObjectTypeAttr {
        ObjectTypeAttr {
            ctxt: self.ctxt,
            handle: self.handle.clone(),
            name: self.name.clone(),
            oratype: self.oratype.clone(),
        }
    }
}

impl fmt::Debug for ObjectTypeAttr {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(
            f,
            "ObjectTypeAttr {{ handle: {:?}, name: {:?}, oratype: {:?} }}",
            self.handle.raw(),
            self.name,
            self.oratype
        )
    }
}

//
// ObjectTypeInternal
//

pub(crate) struct ObjectTypeInternal {
    ctxt: &'static Context,
    handle: DpiObjectType,
    schema: String,
    name: String,
    elem_oratype: Option<OracleType>,
    attrs: Vec<ObjectTypeAttr>,
}

impl ObjectTypeInternal {
    fn from_dpi_object_type(
        ctxt: &'static Context,
        handle: DpiObjectType,
    ) -> Result<ObjectTypeInternal> {
        let mut info = Default::default();
        chkerr!(ctxt, dpiObjectType_getInfo(handle.raw(), &mut info));
        let (elem_oratype, attrs) = if info.isCollection != 0 {
            match OracleType::from_type_info(ctxt, &info.elementTypeInfo) {
                Ok(oratype) => (Some(oratype), Vec::new()),
                Err(err) => return Err(err),
            }
        } else {
            let attrnum = info.numAttributes as usize;
            let mut attr_handles = vec![ptr::null_mut(); attrnum];
            chkerr!(
                ctxt,
                dpiObjectType_getAttributes(
                    handle.raw(),
                    info.numAttributes,
                    attr_handles.as_mut_ptr()
                )
            );
            let mut attrs = Vec::with_capacity(attrnum);
            for i in 0..attrnum {
                match ObjectTypeAttr::new(ctxt, DpiObjectAttr::new(attr_handles[i])) {
                    Ok(attr) => attrs.push(attr),
                    Err(err) => {
                        for j in (i + 1)..attrnum {
                            unsafe {
                                dpiObjectAttr_release(attr_handles[j]);
                            }
                        }
                        return Err(err);
                    }
                }
            }
            (None, attrs)
        };
        Ok(ObjectTypeInternal {
            ctxt: ctxt,
            handle: handle,
            schema: to_rust_str(info.schema, info.schemaLength),
            name: to_rust_str(info.name, info.nameLength),
            elem_oratype: elem_oratype,
            attrs: attrs,
        })
    }
}

impl cmp::PartialEq for ObjectTypeInternal {
    fn eq(&self, other: &Self) -> bool {
        self.handle.raw() == other.handle.raw()
    }
}

impl fmt::Display for ObjectTypeInternal {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}.{}", self.schema, self.name)
    }
}

impl fmt::Debug for ObjectTypeInternal {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        if self.elem_oratype.is_some() {
            write!(
                f,
                "ObjectType({}.{} collection of {})",
                self.schema,
                self.name,
                self.elem_oratype.as_ref().unwrap()
            )
        } else {
            write!(f, "ObjectType({}.{}(", self.schema, self.name)?;
            let mut first = true;
            for attr in &self.attrs {
                if first {
                    first = false;
                } else {
                    write!(f, ", ")?;
                }
                write!(f, "{} {}", attr.name(), attr.oracle_type())?;
            }
            write!(f, "))")
        }
    }
}