use super::OperationPassManager;
use crate::{
    context::Context, ir::Module, logical_result::LogicalResult, pass::Pass, string_ref::StringRef,
    Error,
};
use mlir_sys::{
    mlirPassManagerAddOwnedPass, mlirPassManagerCreate, mlirPassManagerDestroy,
    mlirPassManagerEnableIRPrinting, mlirPassManagerEnableVerifier,
    mlirPassManagerGetAsOpPassManager, mlirPassManagerGetNestedUnder, mlirPassManagerRunOnOp,
    MlirPassManager,
};
use std::marker::PhantomData;

/// A pass manager.
pub struct PassManager<'c> {
    raw: MlirPassManager,
    _context: PhantomData<&'c Context>,
}

impl<'c> PassManager<'c> {
    /// Creates a pass manager.
    pub fn new(context: &Context) -> Self {
        Self {
            raw: unsafe { mlirPassManagerCreate(context.to_raw()) },
            _context: Default::default(),
        }
    }

    /// Returns an operation pass manager for nested operations corresponding to
    /// a given name.
    pub fn nested_under(&self, name: &str) -> OperationPassManager {
        let name = StringRef::new(name);

        unsafe {
            OperationPassManager::from_raw(mlirPassManagerGetNestedUnder(self.raw, name.to_raw()))
        }
    }

    /// Adds a pass.
    pub fn add_pass(&self, pass: Pass) {
        unsafe { mlirPassManagerAddOwnedPass(self.raw, pass.to_raw()) }
    }

    /// Enables a verifier.
    pub fn enable_verifier(&self, enabled: bool) {
        unsafe { mlirPassManagerEnableVerifier(self.raw, enabled) }
    }

    /// Enables IR printing.
    pub fn enable_ir_printing(&self) {
        unsafe { mlirPassManagerEnableIRPrinting(self.raw) }
    }

    /// Runs passes added to a pass manager against a module.
    pub fn run(&self, module: &mut Module) -> Result<(), Error> {
        let result = LogicalResult::from_raw(unsafe {
            mlirPassManagerRunOnOp(self.raw, module.as_operation().to_raw())
        });

        if result.is_success() {
            Ok(())
        } else {
            Err(Error::RunPass)
        }
    }

    /// Converts a pass manager to an operation pass manager.
    pub fn as_operation_pass_manager(&self) -> OperationPassManager {
        unsafe { OperationPassManager::from_raw(mlirPassManagerGetAsOpPassManager(self.raw)) }
    }
}

impl<'c> Drop for PassManager<'c> {
    fn drop(&mut self) {
        unsafe { mlirPassManagerDestroy(self.raw) }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{
        ir::{Location, Module},
        pass::{self, transform::register_print_op_stats},
        test::create_test_context,
        utility::parse_pass_pipeline,
    };
    use indoc::indoc;
    use pretty_assertions::assert_eq;

    #[test]
    fn new() {
        let context = create_test_context();

        PassManager::new(&context);
    }

    #[test]
    fn add_pass() {
        let context = create_test_context();

        PassManager::new(&context).add_pass(pass::conversion::create_func_to_llvm());
    }

    #[test]
    fn enable_verifier() {
        let context = create_test_context();

        PassManager::new(&context).enable_verifier(true);
    }

    // TODO Enable this test.
    // #[test]
    // fn enable_ir_printing() {
    //     let context = Context::new();

    //     PassManager::new(&context).enable_ir_printing();
    // }

    #[test]
    fn run() {
        let context = create_test_context();
        let manager = PassManager::new(&context);

        manager.add_pass(pass::conversion::create_func_to_llvm());
        manager
            .run(&mut Module::new(Location::unknown(&context)))
            .unwrap();
    }

    #[test]
    fn run_on_function() {
        let context = create_test_context();

        let mut module = Module::parse(
            &context,
            indoc!(
                "
                func.func @foo(%arg0 : i32) -> i32 {
                    %res = arith.addi %arg0, %arg0 : i32
                    return %res : i32
                }
                "
            ),
        )
        .unwrap();

        let manager = PassManager::new(&context);
        manager.add_pass(pass::transform::create_print_op_stats());

        assert_eq!(manager.run(&mut module), Ok(()));
    }

    #[test]
    fn run_on_function_in_nested_module() {
        let context = create_test_context();

        let mut module = Module::parse(
            &context,
            indoc!(
                "
                func.func @foo(%arg0 : i32) -> i32 {
                    %res = arith.addi %arg0, %arg0 : i32
                    return %res : i32
                }

                module {
                    func.func @bar(%arg0 : f32) -> f32 {
                        %res = arith.addf %arg0, %arg0 : f32
                        return %res : f32
                    }
                }
                "
            ),
        )
        .unwrap();

        let manager = PassManager::new(&context);
        manager
            .nested_under("func.func")
            .add_pass(pass::transform::create_print_op_stats());

        assert_eq!(manager.run(&mut module), Ok(()));

        let manager = PassManager::new(&context);
        manager
            .nested_under("builtin.module")
            .nested_under("func.func")
            .add_pass(pass::transform::create_print_op_stats());

        assert_eq!(manager.run(&mut module), Ok(()));
    }

    #[test]
    fn print_pass_pipeline() {
        let context = create_test_context();
        let manager = PassManager::new(&context);
        let function_manager = manager.nested_under("func.func");

        function_manager.add_pass(pass::transform::create_print_op_stats());

        assert_eq!(
            manager.as_operation_pass_manager().to_string(),
            "any(func.func(print-op-stats{json=false}))"
        );
        assert_eq!(
            function_manager.to_string(),
            "func.func(print-op-stats{json=false})"
        );
    }

    #[test]
    fn parse_pass_pipeline_() {
        let context = Context::new();
        let manager = PassManager::new(&context);

        insta::assert_snapshot!(parse_pass_pipeline(
            manager.as_operation_pass_manager(),
            "builtin.module(func.func(print-op-stats{json=false}),\
                func.func(print-op-stats{json=false}))"
        )
        .unwrap_err());

        register_print_op_stats();

        assert_eq!(
            parse_pass_pipeline(
                manager.as_operation_pass_manager(),
                "builtin.module(func.func(print-op-stats{json=false}),\
                func.func(print-op-stats{json=false}))"
            ),
            Ok(())
        );

        assert_eq!(
            manager.as_operation_pass_manager().to_string(),
            "builtin.module(func.func(print-op-stats{json=false}),\
            func.func(print-op-stats{json=false}))"
        );
    }
}