1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129

use deno_core::anyhow::bail;
use deno_core::error::AnyError;
use deno_core::futures::FutureExt;
use deno_core::resolve_import;
use deno_core::ModuleLoader;
use deno_core::ModuleSource;
use deno_core::ModuleSourceFuture;
use deno_core::ModuleSpecifier;
use deno_core::ModuleType;
use deno_graph::source::LoadFuture;
use deno_graph::source::LoadResponse;
use deno_graph::source::Loader;
use deno_transpiler::compile;
use std::path::PathBuf;
use std::pin::Pin;
use std::sync::Arc;

use crate::get_source_code;
use crate::ModuleStore;

#[derive(Default, Clone)]
pub struct UniversalModuleLoader {
    store: Option<Arc<dyn ModuleStore>>,
    compile: bool,
}

impl UniversalModuleLoader {
    pub fn new(module_store: Option<Arc<dyn ModuleStore>>, compile: bool) -> Self {
        Self {
            store: module_store,
            compile,
        }
    }

    pub async fn get_and_update_source(
        self,
        m: &ModuleSpecifier,
        minify: bool,
    ) -> Result<String, AnyError> {
        let mut code = get_source_code(m).await?;
        if self.compile {
            code = compile(m, code, minify)?;
        }
        if let Some(store) = self.store.as_ref() {
            store.put(m.to_string(), code.clone());
        }
        Ok(code)
    }
}

impl ModuleLoader for UniversalModuleLoader {
    fn resolve(
        &self,
        specifier: &str,
        referrer: &str,
        _is_main: bool,
    ) -> Result<ModuleSpecifier, AnyError> {
        Ok(resolve_import(specifier, referrer)?)
    }

    fn load(
        &self,
        module_specifier: &ModuleSpecifier,
        _maybe_referrer: Option<ModuleSpecifier>,
        _is_dyn_import: bool,
    ) -> Pin<Box<ModuleSourceFuture>> {
        let m = module_specifier.clone();
        let string_specifier = m.to_string();

        let loader = self.clone();
        async move {
            let module_type = get_module_type(&m)?;
            if let Some(store) = loader.store.as_ref() {
                if let Some(code) = store.get(&string_specifier) {
                    return Ok(ModuleSource {
                        code,
                        module_type,
                        module_url_specified: string_specifier.clone(),
                        module_url_found: string_specifier,
                    });
                }
            }
            let code = loader.get_and_update_source(&m, false).await?;

            Ok(ModuleSource {
                code,
                module_type,
                module_url_specified: string_specifier.clone(),
                module_url_found: string_specifier,
            })
        }
        .boxed_local()
    }
}

impl Loader for UniversalModuleLoader {
    fn load(&mut self, specifier: &ModuleSpecifier, _is_dynamic: bool) -> LoadFuture {
        let loader = self.clone();
        let m = specifier.clone();
        async move {
            let code = loader.get_and_update_source(&m, false).await?;
            Ok(Some(LoadResponse::Module {
                content: Arc::new(code),
                specifier: m,
                maybe_headers: None,
            }))
        }
        .boxed_local()
    }
}

fn get_module_type(m: &ModuleSpecifier) -> Result<ModuleType, AnyError> {
    let path = if let Ok(path) = m.to_file_path() {
        path
    } else {
        PathBuf::from(m.path())
    };
    match path.extension() {
        Some(ext) => {
            let lowercase_str = ext.to_str().map(|s| s.to_lowercase());
            match lowercase_str.as_deref() {
                Some("json") => Ok(ModuleType::Json),
                None => bail!("Unknown extension"),
                _ => Ok(ModuleType::JavaScript),
            }
        }
        None => bail!("Unknown media type {:?}", path),
    }
}