device-driver-generation 1.0.9

use std::ops::{Add, Not};

use anyhow::ensure;

use crate::{
    lir,
    mir::{self, passes::search_object},
};

use super::{
    Integer,
    passes::{find_min_max_addresses, recurse_objects},
};

pub fn transform(device: mir::Device, driver_name: &str) -> anyhow::Result<lir::Device> {
    let lenient_pascal_converter = convert_case::Converter::new()
        .set_boundaries(&convert_case::Boundary::list_from("aA:AAa:_:-: :a1:A1:1A"))
        .set_pattern(convert_case::Pattern::Capital);
    let converted_driver_name = lenient_pascal_converter.convert(driver_name);

    ensure!(
        driver_name == converted_driver_name,
        "The device name must be given in PascalCase, e.g. \"{}\"",
        converted_driver_name
    );

    let mir_enums = collect_enums(&device)?;
    let lir_enums = mir_enums
        .iter()
        .map(|(e, base_type, size_bits)| transform_enum(e, *base_type, *size_bits))
        .collect::<Result<_, anyhow::Error>>()?;

    let field_sets = transform_field_sets(&device, mir_enums.iter().map(|(e, _, _)| e))?;

    // Create a root block and pass the device objects to it
    let blocks = collect_into_blocks(
        BorrowedBlock {
            cfg_attr: &mir::Cfg::new(None),
            description: &format!("Root block of the {driver_name} driver"),
            name: &driver_name.into(),
            address_offset: &0,
            repeat: &None,
            objects: &device.objects,
        },
        true,
        &device.global_config,
        &device.objects,
    )?;

    Ok(lir::Device {
        internal_address_type: find_best_internal_address_type(&device),
        register_address_type: device
            .global_config
            .register_address_type
            .unwrap_or(mir::Integer::U8),
        blocks,
        field_sets,
        enums: lir_enums,
        defmt_feature: device.global_config.defmt_feature,
    })
}

fn collect_into_blocks(
    block: BorrowedBlock,
    is_root: bool,
    global_config: &mir::GlobalConfig,
    device_objects: &[mir::Object],
) -> anyhow::Result<Vec<lir::Block>> {
    let mut blocks = Vec::new();

    let BorrowedBlock {
        cfg_attr,
        description,
        name,
        address_offset: _,
        repeat: _,
        objects,
    } = block;

    let mut methods = Vec::new();

    for object in objects {
        let method = get_method(
            object,
            &mut blocks,
            global_config,
            device_objects,
            "new".to_string(),
        )?;

        methods.push(method);
    }

    let new_block = lir::Block {
        cfg_attr: cfg_attr.to_string(),
        description: description.clone(),
        root: is_root,
        name: name.to_string(),
        methods,
    };

    blocks.insert(0, new_block);

    Ok(blocks)
}

fn get_method(
    object: &mir::Object,
    blocks: &mut Vec<lir::Block>,
    global_config: &mir::GlobalConfig,
    device_objects: &[mir::Object],
    mut register_reset_value_function: String,
) -> Result<lir::BlockMethod, anyhow::Error> {
    use convert_case::Casing;

    Ok(match object {
        mir::Object::Block(
            b @ mir::Block {
                cfg_attr,
                description,
                name,
                address_offset,
                repeat,
                ..
            },
        ) => {
            blocks.extend(collect_into_blocks(
                b.into(),
                false,
                global_config,
                device_objects,
            )?);

            lir::BlockMethod {
                cfg_attr: cfg_attr.to_string(),
                description: description.clone(),
                name: name.to_case(convert_case::Case::Snake),
                address: *address_offset,
                allow_address_overlap: false,
                kind: repeat_to_method_kind(repeat),
                method_type: lir::BlockMethodType::Block {
                    name: name.to_string(),
                },
            }
        }
        mir::Object::Register(mir::Register {
            cfg_attr,
            description,
            name,
            allow_address_overlap,
            address,
            access,
            repeat,
            ..
        }) => lir::BlockMethod {
            cfg_attr: cfg_attr.to_string(),
            description: description.clone(),
            name: name.to_case(convert_case::Case::Snake),
            address: *address,
            allow_address_overlap: *allow_address_overlap,
            kind: repeat_to_method_kind(repeat),
            method_type: lir::BlockMethodType::Register {
                field_set_name: name.to_string(),
                access: *access,
                address_type: global_config
                    .register_address_type
                    .expect("The presence of the address type is already checked in a mir pass"),
                reset_value_function: register_reset_value_function.clone(),
            },
        },
        mir::Object::Command(mir::Command {
            cfg_attr,
            description,
            name,
            allow_address_overlap,
            address,
            repeat,
            in_fields,
            out_fields,
            ..
        }) => lir::BlockMethod {
            cfg_attr: cfg_attr.to_string(),
            description: description.clone(),
            name: name.to_case(convert_case::Case::Snake),
            address: *address,
            allow_address_overlap: *allow_address_overlap,
            kind: repeat_to_method_kind(repeat),
            method_type: lir::BlockMethodType::Command {
                field_set_name_in: in_fields
                    .is_empty()
                    .not()
                    .then(|| format!("{name}FieldsIn")),
                field_set_name_out: out_fields
                    .is_empty()
                    .not()
                    .then(|| format!("{name}FieldsOut")),
                address_type: global_config
                    .command_address_type
                    .expect("The presence of the address type is already checked in a mir pass"),
            },
        },
        mir::Object::Buffer(mir::Buffer {
            cfg_attr,
            description,
            name,
            access,
            address,
        }) => lir::BlockMethod {
            cfg_attr: cfg_attr.to_string(),
            description: description.clone(),
            name: name.to_case(convert_case::Case::Snake),
            address: *address,
            allow_address_overlap: false,
            kind: lir::BlockMethodKind::Normal, // Buffers can't be repeated (for now?)
            method_type: lir::BlockMethodType::Buffer {
                access: *access,
                address_type: global_config
                    .buffer_address_type
                    .expect("The presence of the address type is already checked in a mir pass"),
            },
        },
        mir::Object::Ref(mir::RefObject {
            cfg_attr,
            description,
            name,
            object_override,
        }) => {
            let mut reffed_object = search_object(object_override.name(), device_objects)
                .expect("All refs are validated in a mir pass")
                .clone();

            match object_override {
                mir::ObjectOverride::Block(override_values) => {
                    let reffed_object = reffed_object
                        .as_block_mut()
                        .expect("All refs are validated in a mir pass");
                    reffed_object.cfg_attr = cfg_attr.clone();
                    reffed_object.description = description.clone();

                    if let Some(address_offset) = override_values.address_offset {
                        reffed_object.address_offset = address_offset;
                    }
                    if let Some(repeat) = override_values.repeat {
                        reffed_object.repeat = Some(repeat);
                    }
                }
                mir::ObjectOverride::Register(override_values) => {
                    let reffed_object = reffed_object
                        .as_register_mut()
                        .expect("All refs are validated in a mir pass");
                    reffed_object.cfg_attr = cfg_attr.clone();
                    reffed_object.description = description.clone();

                    if let Some(access) = override_values.access {
                        reffed_object.access = access;
                    }
                    if let Some(address) = override_values.address {
                        reffed_object.address = address;
                    }
                    if let Some(reset_value) = override_values.reset_value.clone() {
                        reffed_object.reset_value = Some(reset_value);
                        register_reset_value_function =
                            format!("new_as_{}", name.to_case(convert_case::Case::Snake));
                    }
                    if let Some(repeat) = override_values.repeat {
                        reffed_object.repeat = Some(repeat);
                    }
                }
                mir::ObjectOverride::Command(override_values) => {
                    let reffed_object = reffed_object
                        .as_command_mut()
                        .expect("All refs are validated in a mir pass");
                    reffed_object.cfg_attr = cfg_attr.clone();
                    reffed_object.description = description.clone();

                    if let Some(address) = override_values.address {
                        reffed_object.address = address;
                    }
                    if let Some(repeat) = override_values.repeat {
                        reffed_object.repeat = Some(repeat);
                    }
                }
            }

            let mut method = get_method(
                &reffed_object,
                blocks,
                global_config,
                device_objects,
                register_reset_value_function,
            )?;

            // We kept the old name in the reffed object so it generates with the correct field sets.
            // But we do want to have the name of ref to be the method name.
            method.name = name.to_case(convert_case::Case::Snake);

            method
        }
    })
}

fn transform_field_sets<'a>(
    device: &mir::Device,
    mir_enums: impl Iterator<Item = &'a mir::Enum> + Clone,
) -> anyhow::Result<Vec<lir::FieldSet>> {
    let mut field_sets = Vec::new();

    recurse_objects(&device.objects, &mut |object| {
        match object {
            mir::Object::Register(r) => {
                let ref_reset_overrides = find_refs(device, object)?
                    .iter()
                    .map(|r| {
                        (
                            &r.name,
                            r.object_override
                                .as_register()
                                .expect("Ref must be register override"),
                        )
                    })
                    .filter_map(|(ref_name, ro)| {
                        ro.reset_value.as_ref().map(|reset_value| {
                            (ref_name.clone(), reset_value.as_array().unwrap().clone())
                        })
                    })
                    .collect();

                field_sets.push(transform_field_set(
                    &r.fields,
                    r.name.clone(),
                    &r.cfg_attr,
                    &r.description,
                    r.byte_order.unwrap(),
                    r.bit_order,
                    r.size_bits,
                    r.reset_value
                        .as_ref()
                        .map(|rv| rv.as_array().unwrap().clone()),
                    ref_reset_overrides,
                    mir_enums.clone(),
                )?);
            }
            mir::Object::Command(c) => {
                if c.size_bits_in != 0 {
                    field_sets.push(transform_field_set(
                        &c.in_fields,
                        format!("{}FieldsIn", c.name),
                        &c.cfg_attr,
                        &c.description,
                        c.byte_order.unwrap(),
                        c.bit_order,
                        c.size_bits_in,
                        None,
                        Vec::new(),
                        mir_enums.clone(),
                    )?);
                }
                if c.size_bits_out != 0 {
                    field_sets.push(transform_field_set(
                        &c.out_fields,
                        format!("{}FieldsOut", c.name),
                        &c.cfg_attr,
                        &c.description,
                        c.byte_order.unwrap(),
                        c.bit_order,
                        c.size_bits_out,
                        None,
                        Vec::new(),
                        mir_enums.clone(),
                    )?);
                }
            }
            _ => {}
        }

        Ok(())
    })?;

    Ok(field_sets)
}

#[allow(clippy::too_many_arguments)] // Though it is correct... it's too many args
fn transform_field_set<'a>(
    field_set: &[mir::Field],
    field_set_name: String,
    cfg_attr: &mir::Cfg,
    description: &str,
    byte_order: mir::ByteOrder,
    bit_order: mir::BitOrder,
    size_bits: u32,
    reset_value: Option<Vec<u8>>,
    ref_reset_overrides: Vec<(String, Vec<u8>)>,
    enum_list: impl Iterator<Item = &'a mir::Enum> + Clone,
) -> anyhow::Result<lir::FieldSet> {
    let fields = field_set
        .iter()
        .map(|field| {
            let mir::Field {
                cfg_attr,
                description,
                name,
                access,
                base_type,
                field_conversion,
                field_address,
            } = field;

            let (base_type, conversion_method) =
                match (base_type, field.field_address.len(), field_conversion) {
                    (mir::BaseType::Unspecified | mir::BaseType::FixedSize(_), _, _) => todo!(),
                    (mir::BaseType::Bool, 1, None) => {
                        ("u8".to_string(), lir::FieldConversionMethod::Bool)
                    }
                    (mir::BaseType::Bool, _, _) => unreachable!(
                        "Checked in a MIR pass. Bools can only be 1 bit and have no conversion"
                    ),
                    (mir::BaseType::Uint | mir::BaseType::Int, val, None) => (
                        format!(
                            "{}{}",
                            match base_type {
                                mir::BaseType::Uint => 'u',
                                mir::BaseType::Int => 'i',
                                _ => unreachable!(),
                            },
                            val.max(8).next_power_of_two()
                        ),
                        lir::FieldConversionMethod::None,
                    ),
                    (mir::BaseType::Uint | mir::BaseType::Int, val, Some(fc)) => (
                        format!(
                            "{}{}",
                            match base_type {
                                mir::BaseType::Uint => 'u',
                                mir::BaseType::Int => 'i',
                                _ => unreachable!(),
                            },
                            val.max(8).next_power_of_two()
                        ),
                        {
                            match enum_list.clone().find(|e| e.name == fc.type_name()) {
                                // Always use try if that's specified
                                _ if fc.use_try() => {
                                    lir::FieldConversionMethod::TryInto(fc.type_name().into())
                                }
                                // There is an enum we generate so we can look at its metadata
                                Some(mir::Enum {
                                    generation_style:
                                        Some(mir::EnumGenerationStyle::Infallible { bit_size }),
                                    ..
                                }) if field.field_address.clone().count() <= *bit_size as usize => {
                                    // This field is equal or smaller in bits than the infallible enum. So we can do the unsafe into
                                    lir::FieldConversionMethod::UnsafeInto(fc.type_name().into())
                                }
                                // Fallback is to require the into trait
                                _ => lir::FieldConversionMethod::Into(fc.type_name().into()),
                            }
                        },
                    ),
                };

            Ok(lir::Field {
                cfg_attr: cfg_attr.to_string(),
                description: description.clone(),
                name: name.clone(),
                address: field_address.clone(),
                base_type,
                conversion_method,
                access: *access,
            })
        })
        .collect::<Result<_, anyhow::Error>>()?;

    Ok(lir::FieldSet {
        cfg_attr: cfg_attr.to_string(),
        description: description.into(),
        name: field_set_name.to_string(),
        byte_order,
        bit_order,
        size_bits,
        reset_value: reset_value.unwrap_or_else(|| vec![0; size_bits.div_ceil(8) as usize]),
        ref_reset_overrides,
        fields,
    })
}

fn collect_enums(device: &mir::Device) -> anyhow::Result<Vec<(mir::Enum, mir::BaseType, usize)>> {
    let mut enums = Vec::new();

    recurse_objects(&device.objects, &mut |object| {
        for field in object.field_sets().flatten() {
            if let Some(mir::FieldConversion::Enum { enum_value, .. }) = &field.field_conversion {
                enums.push((
                    enum_value.clone(),
                    field.base_type,
                    field.field_address.clone().count(),
                ))
            }
        }

        Ok(())
    })?;

    Ok(enums)
}

fn transform_enum(
    e: &mir::Enum,
    base_type: mir::BaseType,
    size_bits: usize,
) -> anyhow::Result<lir::Enum> {
    let mir::Enum {
        cfg_attr,
        description,
        name,
        variants,
        generation_style: _,
    } = e;

    let base_type = match (base_type, size_bits) {
        (mir::BaseType::Bool, _) => "u8".to_string(),
        (mir::BaseType::Uint, val) => format!("u{}", val.max(8).next_power_of_two()),
        (mir::BaseType::Int, val) => format!("i{}", val.max(8).next_power_of_two()),
        (mir::BaseType::Unspecified, _) => {
            todo!()
        }
        (mir::BaseType::FixedSize(_), _) => {
            todo!()
        }
    };

    let mut next_variant_number = None;
    let variants = variants
        .iter()
        .map(|v| {
            let mir::EnumVariant {
                cfg_attr,
                description,
                name,
                value,
            } = v;

            let number = match value {
                mir::EnumValue::Unspecified
                | mir::EnumValue::Default
                | mir::EnumValue::CatchAll => {
                    let val = next_variant_number.unwrap_or_default();
                    next_variant_number = Some(val + 1);
                    val
                }
                mir::EnumValue::Specified(num) => {
                    next_variant_number = Some(*num + 1);
                    *num
                }
            };

            Ok(lir::EnumVariant {
                cfg_attr: cfg_attr.to_string(),
                description: description.clone(),
                name: name.to_string(),
                number,
                default: matches!(value, mir::EnumValue::Default),
                catch_all: matches!(value, mir::EnumValue::CatchAll),
            })
        })
        .collect::<Result<_, anyhow::Error>>()?;

    Ok(lir::Enum {
        cfg_attr: cfg_attr.to_string(),
        description: description.clone(),
        name: name.to_string(),
        base_type,
        variants,
    })
}

fn repeat_to_method_kind(repeat: &Option<mir::Repeat>) -> lir::BlockMethodKind {
    match repeat {
        Some(mir::Repeat { count, stride }) => lir::BlockMethodKind::Repeated {
            count: *count,
            stride: *stride,
        },
        None => lir::BlockMethodKind::Normal,
    }
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct BorrowedBlock<'o> {
    pub cfg_attr: &'o mir::Cfg,
    pub description: &'o String,
    pub name: &'o String,
    pub address_offset: &'o i64,
    pub repeat: &'o Option<mir::Repeat>,
    pub objects: &'o [mir::Object],
}

impl<'o> From<&'o mir::Block> for BorrowedBlock<'o> {
    fn from(value: &'o mir::Block) -> Self {
        let mir::Block {
            cfg_attr,
            description,
            name,
            address_offset,
            repeat,
            objects,
        } = value;

        Self {
            cfg_attr,
            description,
            name,
            address_offset,
            repeat,
            objects,
        }
    }
}

fn find_best_internal_address_type(device: &mir::Device) -> Integer {
    let (min_address_found, max_address_found) = find_min_max_addresses(&device.objects, |_| true);

    let needs_signed = min_address_found < 0;
    let needs_bits = (min_address_found
        .unsigned_abs()
        .max(max_address_found.unsigned_abs())
        .add(1)
        .next_power_of_two()
        .ilog2()
        + needs_signed as u32)
        .next_power_of_two()
        .max(8);

    if needs_signed {
        match needs_bits {
            8 => Integer::I8,
            16 => Integer::I16,
            32 => Integer::I32,
            64 => Integer::I64,
            _ => unreachable!(),
        }
    } else {
        match needs_bits {
            8 => Integer::U8,
            16 => Integer::U16,
            32 => Integer::U32,
            _ => unreachable!(),
        }
    }
}

fn find_refs<'d>(
    device: &'d mir::Device,
    source_object: &mir::Object,
) -> anyhow::Result<Vec<&'d mir::RefObject>> {
    let mut found_refs = Vec::new();

    recurse_objects(&device.objects, &mut |object| {
        if let mir::Object::Ref(ref_object) = object
            && ref_object.object_override.name() == source_object.name()
        {
            found_refs.push(ref_object);
        }

        Ok(())
    })?;

    Ok(found_refs)
}