use crate::base_module::{self, BaseModule, FunctionType, GlobalType};
use anyhow::{anyhow, bail, Result};
use enc::ValType;
use std::{
    collections::{HashMap, HashSet},
    fs::File,
    io::prelude::*,
    path::Path,
};
use wasm_encoder as enc;
use wasmparser::{
    BinaryReader, ExportSectionReader, ExternalKind, FunctionBody, FunctionSectionReader,
    ImportSectionEntryType, ImportSectionReader, TypeSectionReader,
};

pub struct PackConfig {
    compression: Option<u8>,
}

impl PackConfig {
    pub fn with_compression(mut self) -> Self {
        self.compression = Some(2);
        self
    }

    pub fn with_compression_level(mut self, level: u8) -> Self {
        self.compression = Some(level);
        self
    }
}

impl Default for PackConfig {
    fn default() -> PackConfig {
        PackConfig { compression: None }
    }
}

pub fn pack_file(source: &Path, dest: &Path, config: PackConfig) -> Result<()> {
    let mut source_data = vec![];
    File::open(source)?.read_to_end(&mut source_data)?;

    let dest_data = pack(&source_data, config)?;
    File::create(dest)?.write_all(&dest_data)?;

    Ok(())
}

pub fn pack(data: &[u8], config: PackConfig) -> Result<Vec<u8>> {
    let base = BaseModule::for_format_version(1)?;

    let parsed_module = ParsedModule::parse(data)?;
    let result = parsed_module.pack(&base)?;

    if let Some(level) = config.compression {
        let mut uw8 = vec![2];

        let content = &result[8..];
        let mut pb = pbr::ProgressBar::new(content.len() as u64);
        pb.set_units(pbr::Units::Bytes);

        uw8.extend_from_slice(&upkr::pack(
            &result[8..],
            level,
            Some(&mut |pos| {
                pb.set(pos as u64);
            }),
        ));
        pb.finish();
        Ok(uw8)
    } else {
        let mut uw8 = vec![1];
        uw8.extend_from_slice(&result[8..]);
        Ok(uw8)
    }
}

pub fn unpack_file(source: &Path, dest: &Path) -> Result<()> {
    let mut source_data = vec![];
    File::open(source)?.read_to_end(&mut source_data)?;
    let unpacked = unpack(source_data)?;
    File::create(dest)?.write_all(&unpacked)?;
    Ok(())
}

pub fn unpack(data: Vec<u8>) -> Result<Vec<u8>> {
    let (version, data) = match data[0] {
        0 => return Ok(data),
        1 => (1, data[1..].to_vec()),
        2 => (1, upkr::unpack(&data[1..])),
        other => bail!("Uknown format version {}", other),
    };

    let mut data = data.as_slice();
    let base_data = BaseModule::for_format_version(version)?.to_wasm();

    let mut base_data = base_data.as_slice();

    let mut dest = base_data[..8].to_vec();
    base_data = &base_data[8..];

    fn section_length(data: &[u8]) -> Result<usize> {
        let mut reader = BinaryReader::new_with_offset(&data[1..], 1);
        let inner_len = reader.read_var_u32()? as usize;
        let header_len = reader.original_position();
        let len = header_len + inner_len;
        if len > data.len() {
            bail!("Section length greater than size of the rest of the file");
        }
        Ok(len)
    }

    fn copy_section<'a>(dest: &mut Vec<u8>, source: &'a [u8]) -> Result<&'a [u8]> {
        let len = section_length(source)?;
        dest.extend_from_slice(&source[..len]);
        Ok(&source[len..])
    }

    while !data.is_empty() || !base_data.is_empty() {
        if !data.is_empty() && (base_data.is_empty() || data[0] <= base_data[0]) {
            if !base_data.is_empty() && data[0] == base_data[0] {
                base_data = &base_data[section_length(base_data)?..];
            }
            data = copy_section(&mut dest, data)?;
        } else {
            base_data = copy_section(&mut dest, base_data)?;
        }
    }

    Ok(dest)
}

fn to_val_type(type_: &wasmparser::Type) -> Result<ValType> {
    use wasmparser::Type::*;
    Ok(match *type_ {
        I32 => ValType::I32,
        I64 => ValType::I64,
        F32 => ValType::F32,
        F64 => ValType::F64,
        _ => bail!("Type {:?} isn't a value type", type_),
    })
}

fn to_val_type_vec(types: &[wasmparser::Type]) -> Result<Vec<ValType>> {
    types.into_iter().map(to_val_type).collect()
}

#[derive(Debug)]
struct ParsedModule<'a> {
    data: &'a [u8],
    types: Section<Vec<base_module::FunctionType>>,
    imports: Section<ImportSection>,
    globals: Option<Section<u32>>,
    functions: Section<Vec<u32>>,
    exports: Section<Vec<(String, u32)>>,
    start_section: Option<u32>,
    function_bodies: Vec<wasmparser::FunctionBody<'a>>,
    data_section: Option<Section<()>>,
}

impl<'a> ParsedModule<'a> {
    fn parse(data: &'a [u8]) -> Result<ParsedModule<'a>> {
        let mut parser = wasmparser::Parser::new(0);

        let mut type_section = None;
        let mut import_section = None;
        let mut global_section = None;
        let mut function_section = None;
        let mut export_section = None;
        let mut start_section = None;
        let mut function_bodies = Vec::new();
        let mut data_section = None;

        let mut offset = 0;

        loop {
            let (consumed, payload) = if let wasmparser::Chunk::Parsed { consumed, payload } =
                parser.parse(&data[offset..], true)?
            {
                (consumed, payload)
            } else {
                unreachable!();
            };

            use wasmparser::Payload;

            let range = offset..(offset + consumed);

            match payload {
                Payload::Version { .. } => (),
                Payload::TypeSection(reader) => {
                    type_section = Some(Section::new(range, read_type_section(reader)?));
                }
                Payload::ImportSection(reader) => {
                    import_section = Some(Section::new(range, ImportSection::parse(reader)?));
                }
                Payload::GlobalSection(reader) => {
                    global_section = Some(Section::new(range, reader.get_count()));
                }
                Payload::FunctionSection(reader) => {
                    function_section = Some(Section::new(range, read_function_section(reader)?));
                }
                Payload::ExportSection(reader) => {
                    export_section = Some(Section::new(range, read_export_section(reader)?));
                }
                Payload::StartSection { func, .. } => {
                    start_section = Some(func);
                }
                Payload::DataSection(_) => {
                    data_section = Some(Section::new(range, ()));
                }
                Payload::CodeSectionStart { .. } => (),
                Payload::CodeSectionEntry(body) => function_bodies.push(body),
                Payload::CustomSection { .. } => (),
                Payload::End => break,
                other => bail!("Unsupported section: {:?}", other),
            }

            offset += consumed;
        }

        Ok(ParsedModule {
            data,
            types: type_section.ok_or_else(|| anyhow!("No type section found"))?,
            imports: import_section.ok_or_else(|| anyhow!("No import section found"))?,
            globals: global_section,
            functions: function_section.ok_or_else(|| anyhow!("No function section found"))?,
            exports: export_section.ok_or_else(|| anyhow!("No export section found"))?,
            start_section,
            function_bodies,
            data_section,
        })
    }

    fn pack(self, base: &BaseModule) -> Result<Vec<u8>> {
        let mut module = enc::Module::new();

        let mut type_map = HashMap::new();

        let mut uses_base_types = true;

        {
            let base_type_map: HashMap<FunctionType, u32> = base
                .types
                .iter()
                .enumerate()
                .map(|(idx, type_)| (type_.clone(), idx as u32))
                .collect();

            for (idx, type_) in self.types.data.iter().enumerate() {
                if let Some(base_idx) = base_type_map.get(type_) {
                    type_map.insert(idx as u32, *base_idx);
                } else {
                    println!("Type {:?} not found in base", type_);
                    uses_base_types = false;
                }
            }

            if !uses_base_types {
                type_map = (0..self.types.data.len() as u32).map(|i| (i, i)).collect();

                copy_section(&mut module, &self.data[self.types.range.clone()])?;
            }
        }

        let mut function_map = HashMap::new();
        let mut function_count = 0;
        let mut global_map = HashMap::new();
        let mut global_count = 0;

        if uses_base_types {
            if self.imports.data.memory > base.memory {
                bail!(
                    "Trying to import more memory than base ({})",
                    self.imports.data.memory
                );
            }

            let base_import_map: HashMap<(String, String), (u32, u32)> = base
                .function_imports
                .iter()
                .enumerate()
                .map(|(idx, (module, field, type_))| {
                    ((module.to_string(), field.clone()), (*type_, idx as u32))
                })
                .collect();

            for (idx, fnc) in self.imports.data.functions.iter().enumerate() {
                if let Some((base_type, base_idx)) =
                    base_import_map.get(&(fnc.module.clone(), fnc.field.clone()))
                {
                    if type_map.get(&fnc.type_) == Some(base_type) {
                        function_map.insert(idx as u32, *base_idx);
                    } else {
                        bail!(
                            "Import function {}.{} has incompatible type",
                            fnc.module,
                            fnc.field
                        );
                    }
                } else {
                    bail!(
                        "Import function {}.{} not found in base",
                        fnc.module,
                        fnc.field
                    );
                }
            }
            function_count += base.function_imports.len();

            let base_global_import_map: HashMap<(String, String), (GlobalType, u32)> = base
                .global_imports
                .iter()
                .enumerate()
                .map(|(idx, (module, field, type_))| {
                    (
                        (module.to_string(), field.clone()),
                        (type_.clone(), idx as u32),
                    )
                })
                .collect();

            for (idx, glb) in self.imports.data.globals.iter().enumerate() {
                if let Some((base_type, base_idx)) =
                    base_global_import_map.get(&(glb.module.clone(), glb.field.clone()))
                {
                    if base_type == &glb.type_ {
                        global_map.insert(idx as u32, *base_idx);
                    } else {
                        bail!(
                            "Import global {}.{} has incompatible type",
                            glb.module,
                            glb.field
                        );
                    }
                } else {
                    bail!(
                        "Import global {}.{} not found in base",
                        glb.module,
                        glb.field
                    );
                }
            }
            global_count += base.global_imports.len();
        } else {
            copy_section(&mut module, &self.data[self.imports.range.clone()])?;

            function_map = (0..self.imports.data.functions.len() as u32)
                .map(|i| (i, i))
                .collect();
            function_count += self.imports.data.functions.len();

            global_map = (0..self.imports.data.globals.len() as u32)
                .map(|i| (i, i))
                .collect();
            global_count += self.imports.data.globals.len();
        }

        let functions = {
            let mut sorted_functions: Vec<usize> = (0..self.functions.data.len()).collect();
            let exported_functions: HashSet<usize> = self
                .exports
                .data
                .iter()
                .map(|(_, idx)| *idx as usize - self.imports.data.functions.len())
                .collect();
            sorted_functions.sort_by_key(|idx| {
                if exported_functions.contains(idx) {
                    0
                } else {
                    1
                }
            });

            let functions: Vec<_> = sorted_functions
                .iter()
                .map(|i| (&self.functions.data[*i], &self.function_bodies[*i]))
                .collect();

            for i in sorted_functions {
                function_map.insert(
                    self.imports.data.functions.len() as u32 + i as u32,
                    function_count as u32,
                );
                function_count += 1;
            }

            functions
        };

        if functions.len() != base.functions.len()
            || functions
                .iter()
                .zip(base.functions.iter())
                .any(|(a, b)| type_map.get(a.0) != Some(b))
        {
            let mut function_section = enc::FunctionSection::new();
            for (type_, _) in &functions {
                function_section.function(
                    *type_map
                        .get(type_)
                        .ok_or_else(|| anyhow!("Type index out of range: {}", type_))?,
                );
            }
            module.section(&function_section);
        }

        if let Some(ref globals) = self.globals {
            copy_section(&mut module, &self.data[globals.range.clone()])?;
            for i in 0..globals.data {
                global_map.insert(
                    self.imports.data.globals.len() as u32 + i,
                    global_count as u32,
                );
                global_count += 1;
            }
        }

        {
            let base_exports = base.exports.clone();

            let my_exports: Vec<(String, u32)> = self
                .exports
                .data
                .iter()
                .map(|(name, func)| (name.clone(), *function_map.get(func).unwrap()))
                .collect();

            if base_exports.len() != my_exports.len()
                || base_exports
                    .iter()
                    .zip(my_exports.iter())
                    .any(|((n1, t1), (n2, t2))| n1 != n2 || t1 != t2)
            {
                let mut export_section = enc::ExportSection::new();
                for (name, fnc) in my_exports {
                    export_section.export(&name, enc::Export::Function(fnc));
                }
                module.section(&export_section);
            }
        }

        if let Some(start_function) = self.start_section {
            module.section(&enc::StartSection {
                function_index: *function_map.get(&start_function).unwrap(),
            });
        }

        {
            let mut code_section = enc::CodeSection::new();

            for (_, function) in &functions {
                code_section.function(&remap_function(
                    function,
                    &type_map,
                    &function_map,
                    &global_map,
                )?);
            }

            module.section(&code_section);
        }

        if let Some(ref data_section) = self.data_section {
            copy_section(&mut module, &self.data[data_section.range.clone()])?;
        }

        Ok(module.finish())
    }
}

fn copy_section(module: &mut wasm_encoder::Module, data: &[u8]) -> Result<()> {
    let mut reader = wasmparser::BinaryReader::new(data);
    let id = reader.read_u8()? as u8;
    let size = reader.read_var_u32()?;

    let data = &data[reader.current_position()..];
    assert!(data.len() == size as usize);

    module.section(&wasm_encoder::RawSection { id, data });

    Ok(())
}

fn read_type_section(reader: TypeSectionReader) -> Result<Vec<base_module::FunctionType>> {
    let mut function_types = vec![];

    for type_def in reader {
        match type_def? {
            wasmparser::TypeDef::Func(fnc) => {
                if fnc.returns.len() > 1 {
                    bail!("Multi-value not supported");
                }
                let params = to_val_type_vec(&fnc.params)?;
                let result = to_val_type_vec(&fnc.returns)?.into_iter().next();
                function_types.push(FunctionType { params, result });
            }
            t => bail!("Unsupported type def {:?}", t),
        }
    }

    Ok(function_types)
}

#[derive(Debug)]
struct Section<T> {
    range: std::ops::Range<usize>,
    data: T,
}

impl<T> Section<T> {
    fn new(range: std::ops::Range<usize>, data: T) -> Section<T> {
        Section { range, data }
    }
}

#[derive(Debug)]
struct ImportSection {
    memory: u32,
    functions: Vec<FunctionImport>,
    globals: Vec<GlobalImport>,
}

impl ImportSection {
    fn parse(reader: ImportSectionReader) -> Result<ImportSection> {
        let mut memory = 0;
        let mut functions = vec![];
        let mut globals = vec![];

        for import in reader {
            let import = import?;
            if let Some(field) = import.field {
                match import.ty {
                    ImportSectionEntryType::Function(type_) => {
                        functions.push(FunctionImport {
                            module: import.module.to_string(),
                            field: field.to_string(),
                            type_,
                        });
                    }
                    ImportSectionEntryType::Memory(mem) => {
                        if import.module != "env" || field != "memory" {
                            bail!(
                                "Wrong name of memory import {}.{}, should be env.memory",
                                import.module,
                                field
                            );
                        }
                        if mem.memory64 || mem.shared {
                            bail!("Wrong memory import options: {:?}", import.ty);
                        }
                        memory = mem.maximum.unwrap_or(mem.initial) as u32;
                    }
                    ImportSectionEntryType::Global(glbl) => {
                        globals.push(GlobalImport {
                            module: import.module.to_string(),
                            field: field.to_string(),
                            type_: GlobalType {
                                type_: to_val_type(&glbl.content_type)?,
                                mutable: glbl.mutable,
                            },
                        });
                    }
                    _ => bail!("Unsupported import item {:?}", import.ty),
                }
            } else {
                bail!(
                    "Found import without field, only module '{}'",
                    import.module
                );
            }
        }

        if memory == 0 {
            bail!("No memory import found");
        }

        Ok(ImportSection {
            memory,
            functions,
            globals,
        })
    }
}

#[derive(Debug)]
struct FunctionImport {
    module: String,
    field: String,
    type_: u32,
}

#[derive(Debug)]
struct GlobalImport {
    module: String,
    field: String,
    type_: GlobalType,
}

fn read_function_section(reader: FunctionSectionReader) -> Result<Vec<u32>> {
    let mut functions = vec![];
    for func_type in reader {
        functions.push(func_type?);
    }
    Ok(functions)
}

fn read_export_section(reader: ExportSectionReader) -> Result<Vec<(String, u32)>> {
    let mut function_exports = Vec::new();
    for export in reader {
        let export = export?;
        match export.kind {
            ExternalKind::Function => {
                function_exports.push((export.field.to_string(), export.index));
            }
            _ => (), // just ignore all other kinds since MicroW8 doesn't expect any exports other than functions
        }
    }
    Ok(function_exports)
}

fn remap_function(
    reader: &FunctionBody,
    type_map: &HashMap<u32, u32>,
    function_map: &HashMap<u32, u32>,
    global_map: &HashMap<u32, u32>,
) -> Result<enc::Function> {
    let mut locals = Vec::new();
    for local in reader.get_locals_reader()? {
        let (count, type_) = local?;
        locals.push((count, to_val_type(&type_)?));
    }
    let mut function = enc::Function::new(locals);

    let block_type = |ty: wasmparser::TypeOrFuncType| -> Result<enc::BlockType> {
        Ok(match ty {
            wasmparser::TypeOrFuncType::Type(wasmparser::Type::EmptyBlockType) => {
                enc::BlockType::Empty
            }
            wasmparser::TypeOrFuncType::Type(ty) => enc::BlockType::Result(to_val_type(&ty)?),
            wasmparser::TypeOrFuncType::FuncType(ty) => enc::BlockType::FunctionType(
                *type_map
                    .get(&ty)
                    .ok_or_else(|| anyhow!("Function type index out of range: {}", ty))?,
            ),
        })
    };

    let global_idx = |idx: u32| -> Result<u32> {
        Ok(*global_map
            .get(&idx)
            .ok_or_else(|| anyhow!("Global index out of range: {}", idx))?)
    };

    fn mem(m: wasmparser::MemoryImmediate) -> enc::MemArg {
        enc::MemArg {
            offset: m.offset,
            align: m.align as u32,
            memory_index: m.memory,
        }
    }

    use enc::Instruction as En;
    use wasmparser::Operator as De;

    for op in reader.get_operators_reader()? {
        function.instruction(&match op? {
            De::Unreachable => En::Unreachable,
            De::Nop => En::Nop,
            De::Block { ty } => En::Block(block_type(ty)?),
            De::Loop { ty } => En::Loop(block_type(ty)?),
            De::If { ty } => En::If(block_type(ty)?),
            De::Else => En::Else,
            De::Try { .. } | De::Catch { .. } | De::Throw { .. } | De::Rethrow { .. } => todo!(),
            De::End => En::End,
            De::Br { relative_depth } => En::Br(relative_depth),
            De::BrIf { relative_depth } => En::BrIf(relative_depth),
            De::BrTable { .. } => todo!(),
            De::Return => En::Return,
            De::Call { function_index } => En::Call(
                *function_map
                    .get(&function_index)
                    .ok_or_else(|| anyhow!("Function index out of range: {}", function_index))?,
            ),
            De::CallIndirect { .. }
            | De::ReturnCall { .. }
            | De::ReturnCallIndirect { .. }
            | De::Delegate { .. }
            | De::CatchAll => todo!(),
            De::Drop => En::Drop,
            De::Select => En::Select,
            De::TypedSelect { .. } => todo!(),
            De::LocalGet { local_index } => En::LocalGet(local_index),
            De::LocalSet { local_index } => En::LocalSet(local_index),
            De::LocalTee { local_index } => En::LocalTee(local_index),
            De::GlobalGet { global_index } => En::GlobalGet(global_idx(global_index)?),
            De::GlobalSet { global_index } => En::GlobalSet(global_idx(global_index)?),
            De::I32Load { memarg } => En::I32Load(mem(memarg)),
            De::I64Load { memarg } => En::I64Load(mem(memarg)),
            De::F32Load { memarg } => En::F32Load(mem(memarg)),
            De::F64Load { memarg } => En::F64Load(mem(memarg)),
            De::I32Load8S { memarg } => En::I32Load8_S(mem(memarg)),
            De::I32Load8U { memarg } => En::I32Load8_U(mem(memarg)),
            De::I32Load16S { memarg } => En::I32Load16_S(mem(memarg)),
            De::I32Load16U { memarg } => En::I32Load16_U(mem(memarg)),
            De::I64Load8S { memarg } => En::I64Load8_S(mem(memarg)),
            De::I64Load8U { memarg } => En::I64Load8_U(mem(memarg)),
            De::I64Load16S { memarg } => En::I64Load16_S(mem(memarg)),
            De::I64Load16U { memarg } => En::I64Load16_U(mem(memarg)),
            De::I64Load32S { memarg } => En::I64Load32_S(mem(memarg)),
            De::I64Load32U { memarg } => En::I64Load32_U(mem(memarg)),
            De::I32Store { memarg } => En::I32Store(mem(memarg)),
            De::I64Store { memarg } => En::I64Store(mem(memarg)),
            De::F32Store { memarg } => En::F32Store(mem(memarg)),
            De::F64Store { memarg } => En::F64Store(mem(memarg)),
            De::I32Store8 { memarg } => En::I32Store8(mem(memarg)),
            De::I32Store16 { memarg } => En::I32Store16(mem(memarg)),
            De::I64Store8 { memarg } => En::I64Store8(mem(memarg)),
            De::I64Store16 { memarg } => En::I64Store16(mem(memarg)),
            De::I64Store32 { memarg } => En::I64Store32(mem(memarg)),
            De::MemorySize { mem, mem_byte: _ } => En::MemorySize(mem),
            De::MemoryGrow { mem, mem_byte: _ } => En::MemoryGrow(mem),
            De::I32Const { value } => En::I32Const(value),
            De::I64Const { value } => En::I64Const(value),
            De::F32Const { value } => En::F32Const(f32::from_bits(value.bits())),
            De::F64Const { value } => En::F64Const(f64::from_bits(value.bits())),
            De::RefNull { .. } | De::RefIsNull { .. } | De::RefFunc { .. } => todo!(),
            De::I32Eqz => En::I32Eqz,
            De::I32Eq => En::I32Eq,
            De::I32Ne => En::I32Neq,
            De::I32LtS => En::I32LtS,
            De::I32LtU => En::I32LtU,
            De::I32GtS => En::I32GtS,
            De::I32GtU => En::I32GtU,
            De::I32LeS => En::I32LeS,
            De::I32LeU => En::I32LeU,
            De::I32GeS => En::I32GeS,
            De::I32GeU => En::I32GeU,
            De::I64Eqz => En::I64Eqz,
            De::I64Eq => En::I64Eq,
            De::I64Ne => En::I64Neq,
            De::I64LtS => En::I64LtS,
            De::I64LtU => En::I64LtU,
            De::I64GtS => En::I64GtS,
            De::I64GtU => En::I64GtU,
            De::I64LeS => En::I64LeS,
            De::I64LeU => En::I64LeU,
            De::I64GeS => En::I64GeS,
            De::I64GeU => En::I64GeU,
            De::F32Eq => En::F32Eq,
            De::F32Ne => En::F32Neq,
            De::F32Lt => En::F32Lt,
            De::F32Gt => En::F32Gt,
            De::F32Le => En::F32Le,
            De::F32Ge => En::F32Ge,
            De::F64Eq => En::F64Eq,
            De::F64Ne => En::F64Neq,
            De::F64Lt => En::F64Lt,
            De::F64Gt => En::F64Gt,
            De::F64Le => En::F64Le,
            De::F64Ge => En::F64Ge,
            De::I32Clz => En::I32Clz,
            De::I32Ctz => En::I32Ctz,
            De::I32Popcnt => En::I32Popcnt,
            De::I32Add => En::I32Add,
            De::I32Sub => En::I32Sub,
            De::I32Mul => En::I32Mul,
            De::I32DivS => En::I32DivS,
            De::I32DivU => En::I32DivU,
            De::I32RemS => En::I32RemS,
            De::I32RemU => En::I32RemU,
            De::I32And => En::I32And,
            De::I32Or => En::I32Or,
            De::I32Xor => En::I32Xor,
            De::I32Shl => En::I32Shl,
            De::I32ShrS => En::I32ShrS,
            De::I32ShrU => En::I32ShrU,
            De::I32Rotl => En::I32Rotl,
            De::I32Rotr => En::I32Rotr,
            De::I64Clz => En::I64Clz,
            De::I64Ctz => En::I64Ctz,
            De::I64Popcnt => En::I64Popcnt,
            De::I64Add => En::I64Add,
            De::I64Sub => En::I64Sub,
            De::I64Mul => En::I64Mul,
            De::I64DivS => En::I64DivS,
            De::I64DivU => En::I64DivU,
            De::I64RemS => En::I64RemS,
            De::I64RemU => En::I64RemU,
            De::I64And => En::I64And,
            De::I64Or => En::I64Or,
            De::I64Xor => En::I64Xor,
            De::I64Shl => En::I64Shl,
            De::I64ShrS => En::I64ShrS,
            De::I64ShrU => En::I64ShrU,
            De::I64Rotl => En::I64Rotl,
            De::I64Rotr => En::I64Rotr,
            De::F32Abs => En::F32Abs,
            De::F32Neg => En::F32Neg,
            De::F32Ceil => En::F32Ceil,
            De::F32Floor => En::F32Floor,
            De::F32Trunc => En::F32Trunc,
            De::F32Nearest => En::F32Nearest,
            De::F32Sqrt => En::F32Sqrt,
            De::F32Add => En::F32Add,
            De::F32Sub => En::F32Sub,
            De::F32Mul => En::F32Mul,
            De::F32Div => En::F32Div,
            De::F32Min => En::F32Min,
            De::F32Max => En::F32Max,
            De::F32Copysign => En::F32Copysign,
            De::F64Abs => En::F64Abs,
            De::F64Neg => En::F64Neg,
            De::F64Ceil => En::F64Ceil,
            De::F64Floor => En::F64Floor,
            De::F64Trunc => En::F64Trunc,
            De::F64Nearest => En::F64Nearest,
            De::F64Sqrt => En::F64Sqrt,
            De::F64Add => En::F64Add,
            De::F64Sub => En::F64Sub,
            De::F64Mul => En::F64Mul,
            De::F64Div => En::F64Div,
            De::F64Min => En::F64Min,
            De::F64Max => En::F64Max,
            De::F64Copysign => En::F64Copysign,
            De::I32WrapI64 => En::I32WrapI64,
            De::I32TruncF32S => En::I32TruncF32S,
            De::I32TruncF32U => En::I32TruncF32U,
            De::I32TruncF64S => En::I32TruncF64S,
            De::I32TruncF64U => En::I32TruncF64U,
            De::I64ExtendI32S => En::I64ExtendI32S,
            De::I64ExtendI32U => En::I64ExtendI32U,
            De::I64TruncF32S => En::I64TruncF32S,
            De::I64TruncF32U => En::I64TruncF32U,
            De::I64TruncF64S => En::I64TruncF64S,
            De::I64TruncF64U => En::I64TruncF64U,
            De::F32ConvertI32S => En::F32ConvertI32S,
            De::F32ConvertI32U => En::F32ConvertI32U,
            De::F32ConvertI64S => En::F32ConvertI64S,
            De::F32ConvertI64U => En::F32ConvertI64U,
            De::F32DemoteF64 => En::F32DemoteF64,
            De::F64ConvertI32S => En::F64ConvertI32S,
            De::F64ConvertI32U => En::F64ConvertI32U,
            De::F64ConvertI64S => En::F64ConvertI64S,
            De::F64ConvertI64U => En::F64ConvertI64U,
            De::F64PromoteF32 => En::F64PromoteF32,
            De::I32ReinterpretF32 => En::I32ReinterpretF32,
            De::I64ReinterpretF64 => En::I64ReinterpretF64,
            De::F32ReinterpretI32 => En::F32ReinterpretI32,
            De::F64ReinterpretI64 => En::F64ReinterpretI64,
            De::I32Extend8S => En::I32Extend8S,
            De::I32Extend16S => En::I32Extend16S,
            De::I64Extend8S => En::I64Extend8S,
            De::I64Extend16S => En::I64Extend16S,
            De::I64Extend32S => En::I64Extend32S,
            De::I32TruncSatF32S => En::I32TruncSatF32S,
            De::I32TruncSatF32U => En::I32TruncSatF32U,
            De::I32TruncSatF64S => En::I32TruncSatF64S,
            De::I32TruncSatF64U => En::I32TruncSatF64U,
            De::I64TruncSatF32S => En::I64TruncSatF32S,
            De::I64TruncSatF32U => En::I64TruncSatF32U,
            De::I64TruncSatF64S => En::I64TruncSatF64S,
            De::I64TruncSatF64U => En::I64TruncSatF64U,
            other => bail!("Unsupported instruction {:?}", other),
        });
    }

    Ok(function)
}