use crate::elm;
use crate::reporting::{CompilerError, Problem};
use crate::PortableHash;
use std::hash::Hasher;
use std::io::Write;
use std::path::PathBuf;
use tracing::info_span;

mod astrid_pages;
mod css_in_elm;
mod fixtures;
mod scripting;

pub(crate) fn exec(
    file: PathBuf,
    debug: bool,
    function: String,
    input_source: Option<PathBuf>,
    output: Option<PathBuf>,
    verbosity: u64,
    sqlite_path: Option<PathBuf>,
) -> Result<(), Problem> {
    // Our first elm make call is where we build the users program. There is a pretty good chance
    // this won't work.
    elm::make(&file, debug, verbosity)?;

    // Step 2, find the elm.json and elm-stuff directory
    let elm_project_dir =
        elm::find_project_root("elm.json", "./").map_err(CompilerError::MissingElmJson)?;

    let elm_cache_dir = elm_project_dir.join("elm-stuff").join("0.19.1");

    if !elm_cache_dir.is_dir() {
        return Err(CompilerError::MissingElmStuff(elm_cache_dir).into());
    }

    // step 2.5 get the module name out of the file.
    let data = std::fs::read(&file)
        .map_err(|io_err| CompilerError::ReadInputFailed(io_err, file.clone()))?;

    let entrypoint = elmi::Global(
        elmi::ModuleNameCanonical {
            package: elmi::PackageName::new("author", "project"),
            module: elm::parse_module_name(&data)?,
        },
        elmi::Name(function.clone()),
    );

    // step 3 find all the filepaths in the elm-stuff/0.19.1/* folder
    let interfaces = elm::load_interfaces(&elm_cache_dir)?;

    // Step 5, check for the desired function
    let span = info_span!("resolved target function");
    let timing_guard = span.enter();
    let mode = match interfaces.get(&entrypoint.0) {
        Some(interface) => match interface.values.get(&entrypoint.1) {
            Some(annotation) => {
                let elmi::CannonicalAnnotation(_free_vars, tipe) = annotation;

                if is_astrid_pages_route(tipe) {
                    ExecutionMode::AstridPagesRoute
                } else if is_css_in_elm_stylesheet(tipe) {
                    ExecutionMode::CssInElm
                } else {
                    let (input_type, output_type) = scripting::resolve_function_type(tipe)?;
                    ExecutionMode::Scripting(input_type, output_type)
                }
            }
            None => return Err(CompilerError::BadImport(entrypoint).into()),
        },
        None => return Err(CompilerError::MissingModuleTypeInformation(entrypoint.0).into()),
    };
    drop(timing_guard);

    let mut hasher = PortableHash::new();
    hasher.write_all(&data).unwrap();
    // also include the function name in the checksum so users can run multiple functions
    // from the same file but still get caching if the file does not change.
    hasher.write_all(function.as_bytes()).unwrap();
    let source_checksum = hasher.finish();

    match mode {
        ExecutionMode::Scripting(input_type, output_type) => scripting::run(
            debug,
            verbosity,
            sqlite_path,
            elm_project_dir,
            source_checksum,
            entrypoint,
            input_type,
            output_type,
            input_source,
            output,
        ),
        ExecutionMode::AstridPagesRoute => astrid_pages::run(
            debug,
            verbosity,
            sqlite_path,
            elm_project_dir,
            source_checksum,
            entrypoint,
            output,
        ),
        ExecutionMode::CssInElm => css_in_elm::run(
            debug,
            verbosity,
            elm_project_dir,
            source_checksum,
            entrypoint,
            output,
        ),
    }
}

enum ExecutionMode {
    AstridPagesRoute,
    CssInElm,
    Scripting(Option<scripting::InputType>, scripting::OutputType),
}

fn is_astrid_pages_route(tipe: &elmi::Type) -> bool {
    match tipe {
        elmi::Type::TType(module_name, name, _args) => {
            module_name == "author/project/Astrid.Pages" && name == "Route"
        }
        _ => false,
    }
}

fn is_css_in_elm_stylesheet(tipe: &elmi::Type) -> bool {
    match tipe {
        elmi::Type::TType(module_name, name, args) => {
            if module_name == "elm/core/List" && name == "List" && args.len() == 1 {
                match &args[0] {
                    elmi::Type::TTuple(a, b, None) => {
                        match &**a {
                            elmi::Type::TType(module_name, name, _)
                                if module_name == "elm/core/String" && name == "String" => (),
                            _ => return false,
                        }
                        match &**b {
                            elmi::Type::TType(module_name, name, args)
                                if module_name == "elm/core/List" && name == "List" && args.len() == 1 =>
                            {
                                match &args[0] {
                                    elmi::Type::TAlias(module_name, name, _, _)
                                        if module_name == "ThinkAlexandria/css-in-elm/Css" && name == "Stylesheet" => return true,
                                    _ => (),
                                }
                            }
                            _ => (),
                        }
                    }
                    _ => (),
                }
            }
            
        }
        _ => (),
    }
    false
}

mod runtime {
    use crate::reporting::InterpreterError;
    use deno_core::error::{type_error, AnyError};
    use deno_core::futures::FutureExt;
    use deno_core::{resolve_url, Extension, FsModuleLoader, ModuleLoader, ModuleSpecifier};
    use deno_runtime::deno_broadcast_channel::InMemoryBroadcastChannel;
    use deno_runtime::permissions::Permissions;
    use deno_runtime::worker::MainWorker;
    use deno_runtime::worker::WorkerOptions;
    use deno_runtime::BootstrapOptions;
    use deno_web::BlobStore;
    use std::pin::Pin;
    use std::rc::Rc;
    use std::sync::Arc;
    use tracing::{info_span, Instrument};

    fn get_error_class_name(e: &AnyError) -> &'static str {
        deno_runtime::errors::get_error_class_name(e).unwrap_or("Error")
    }

    pub fn setup_worker(
        extensions: Vec<Extension>,
        path_str: &str,
    ) -> Result<(MainWorker, ModuleSpecifier), AnyError> {
        //let module_loader = Rc::new(EmbeddedModuleLoader("void".to_owned()));
        let module_loader = Rc::new(FsModuleLoader);
        let create_web_worker_cb = Arc::new(|_| {
            todo!("Web workers are not supported in the example");
        });
        let web_worker_preload_module_cb = Arc::new(|_| {
            todo!("Web workers are not supported in the example");
        });

        let options = WorkerOptions {
            bootstrap: BootstrapOptions {
                args: vec![],
                apply_source_maps: false,
                cpu_count: 1,
                debug_flag: false,
                enable_testing_features: false,
                is_tty: false,
                location: None,
                no_color: false,
                runtime_version: "0.50.0".to_string(),
                ts_version: "2.0.0".to_string(),
                unstable: false,
            },
            extensions: extensions,
            unsafely_ignore_certificate_errors: None,
            root_cert_store: None,
            user_agent: "hello_runtime".to_string(),
            seed: None,
            module_loader,
            create_web_worker_cb,
            web_worker_preload_module_cb,
            js_error_create_fn: None,
            maybe_inspector_server: None,
            should_break_on_first_statement: false,
            get_error_class_fn: Some(&get_error_class_name),
            origin_storage_dir: None,
            blob_store: BlobStore::default(),
            broadcast_channel: InMemoryBroadcastChannel::default(),
            shared_array_buffer_store: None,
            compiled_wasm_module_store: None,
        };

        let main_module = deno_core::resolve_path(path_str)?;
        // note: resolve_url is just calling url::Url::parse and mapping the error type
        // let main_module = resolve_url(SPECIFIER)?;
        let permissions = Permissions::allow_all();

        let worker = MainWorker::from_options(main_module.clone(), permissions, options);
        //worker.bootstrap(&options);

        Ok((worker, main_module))
    }

    pub async fn xyz<F>(
        mut worker: MainWorker,
        main_module: ModuleSpecifier,
        foo: F,
    ) -> Result<(), InterpreterError>
    where
        F: FnOnce(deno_core::v8::HandleScope) -> Result<(), InterpreterError>,
    {
        let wait_for_inspector = false;
        // step 10 load the module into our v8 isolate
        worker
            .execute_main_module(&main_module)
            .instrument(info_span!("execute main module"))
            .await?;
        worker
            .run_event_loop(wait_for_inspector)
            .instrument(info_span!("run v8 event loop"))
            .await?;

        let scope_outer = worker.js_runtime.handle_scope();

        foo(scope_outer)?;

        worker
            .run_event_loop(wait_for_inspector)
            .instrument(info_span!("run v8 event loop"))
            .await?;

        Ok(())
    }

    const SPECIFIER: &str = "file://$deno$/bundle.js";

    struct EmbeddedModuleLoader(String);

    impl ModuleLoader for EmbeddedModuleLoader {
        fn resolve(
            &self,
            specifier: &str,
            _referrer: &str,
            _is_main: bool,
        ) -> Result<ModuleSpecifier, AnyError> {
            if let Ok(module_specifier) = resolve_url(specifier) {
                //if get_source_from_data_url(&module_specifier).is_ok()
                //  || specifier == SPECIFIER
                //{
                return Ok(module_specifier);
                //}
            }
            Err(type_error(
                "Self-contained binaries don't support module loading",
            ))
        }

        fn load(
            &self,
            module_specifier: &ModuleSpecifier,
            _maybe_referrer: Option<ModuleSpecifier>,
            _is_dyn_import: bool,
        ) -> Pin<Box<deno_core::ModuleSourceFuture>> {
            let module_specifier = module_specifier.clone();
            //let is_data_uri = get_source_from_data_url(&module_specifier).ok();
            //let code = if let Some((ref source, _)) = is_data_uri {
            //  source.to_string()
            //} else {
            let code = self.0.to_string();
            //};
            async move {
                //if is_data_uri.is_none() && module_specifier.to_string() != SPECIFIER {
                //  return Err(type_error(
                //    "Self-contained binaries don't support module loading",
                //  ));
                //}

                Ok(deno_core::ModuleSource {
                    code,
                    module_type: deno_core::ModuleType::JavaScript,
                    module_url_specified: module_specifier.to_string(),
                    module_url_found: module_specifier.to_string(),
                })
            }
            .boxed_local()
        }
    }
}