#![allow(unused_imports)]
#![allow(unused_variables)]
#[cfg(feature = "__plugin_mode")]
use swc_common::{
    source_map::{
        DistinctSources, FileLinesResult, MalformedSourceMapPositions, PartialFileLinesResult,
        PartialLoc, SmallPos, SpanSnippetError,
    },
    sync::Lrc,
    BytePos, FileName, Loc, SourceFileAndBytePos, SourceMapper, Span,
};
use swc_common::{sync::OnceCell, CharPos, FileLines, SourceFile};
#[cfg(feature = "__plugin_mode")]
use swc_ecma_ast::SourceMapperExt;
use swc_trace_macro::swc_trace;

#[cfg(all(feature = "__rkyv", feature = "__plugin_mode", target_arch = "wasm32"))]
use crate::memory_interop::read_returned_result_from_host;

#[cfg(target_arch = "wasm32")]
extern "C" {
    fn __lookup_char_pos_source_map_proxy(
        byte_pos: u32,
        should_include_source_file: i32,
        allocated_ret_ptr: u32,
    ) -> u32;
    fn __doctest_offset_line_proxy(orig: u32) -> u32;
    fn __merge_spans_proxy(
        lhs_lo: u32,
        lhs_hi: u32,
        rhs_lo: u32,
        rhs_hi: u32,
        allocated_ptr: u32,
    ) -> u32;
    fn __span_to_string_proxy(span_lo: u32, span_hi: u32, allocated_ret_ptr: u32) -> u32;
    fn __span_to_filename_proxy(span_lo: u32, span_hi: u32, allocated_ret_ptr: u32) -> u32;
    fn __span_to_source_proxy(span_lo: u32, span_hi: u32, allocated_ret_ptr: u32) -> u32;
    fn __span_to_lines_proxy(
        span_lo: u32,
        span_hi: u32,
        should_request_source_file: i32,
        allocated_ret_ptr: u32,
    ) -> u32;
    fn __lookup_byte_offset_proxy(byte_pos: u32, allocated_ret_ptr: u32) -> u32;
}

#[cfg(feature = "__plugin_mode")]
#[derive(Debug, Clone)]
pub struct PluginSourceMapProxy {
    // Sharable instance to `SourceFile` per plugin transform.
    // Since each plugin's lifecycle is tied to single `transform`,
    // We know this'll be the same across subsequent request for lookup_char_*.
    pub source_file: OnceCell<swc_common::sync::Lrc<SourceFile>>,
}

#[cfg(all(feature = "__rkyv", feature = "__plugin_mode", target_arch = "wasm32"))]
#[swc_trace]
impl PluginSourceMapProxy {
    pub fn span_to_source<F, Ret>(
        &self,
        sp: Span,
        extract_source: F,
    ) -> Result<Ret, Box<SpanSnippetError>>
    where
        F: FnOnce(&str, usize, usize) -> Ret,
    {
        #[cfg(target_arch = "wasm32")]
        {
            let src: Result<String, Box<SpanSnippetError>> =
                read_returned_result_from_host(|serialized_ptr| unsafe {
                    __span_to_source_proxy(sp.lo.0, sp.hi.0, serialized_ptr)
                })
                .expect("Host should return source code");

            let src = src?;
            return Ok(extract_source(&src, 0, src.len()));
        }

        #[cfg(not(target_arch = "wasm32"))]
        unimplemented!("Sourcemap proxy cannot be called in this context")
    }
}

/// Subset of SourceMap interface supported in plugin.
/// Unlike `Comments`, this does not fully implement `SourceMap`.
#[cfg(feature = "__plugin_mode")]
impl SourceMapper for PluginSourceMapProxy {
    #[cfg_attr(not(target_arch = "wasm32"), allow(unused))]
    fn lookup_char_pos(&self, pos: BytePos) -> Loc {
        #[cfg(target_arch = "wasm32")]
        {
            let should_request_source_file = if self.source_file.get().is_none() {
                1
            } else {
                0
            };
            let partial_loc: PartialLoc = read_returned_result_from_host(|serialized_ptr| unsafe {
                __lookup_char_pos_source_map_proxy(
                    pos.0,
                    should_request_source_file,
                    serialized_ptr,
                )
            })
            .expect("Host should return PartialLoc");

            if self.source_file.get().is_none() {
                if let Some(source_file) = partial_loc.source_file {
                    self.source_file
                        .set(source_file)
                        .expect("Should able to set source file");
                }
            }

            return Loc {
                file: self
                    .source_file
                    .get()
                    .expect("SourceFile should exist")
                    .clone(),
                line: partial_loc.line,
                col: CharPos(partial_loc.col),
                col_display: partial_loc.col_display,
            };
        }

        #[cfg(not(target_arch = "wasm32"))]
        unimplemented!("Sourcemap proxy cannot be called in this context")
    }

    fn span_to_lines(&self, sp: Span) -> FileLinesResult {
        #[cfg(target_arch = "wasm32")]
        {
            let should_request_source_file = if self.source_file.get().is_none() {
                1
            } else {
                0
            };
            let partial_files: PartialFileLinesResult =
                read_returned_result_from_host(|serialized_ptr| unsafe {
                    __span_to_lines_proxy(
                        sp.lo.0,
                        sp.hi.0,
                        should_request_source_file,
                        serialized_ptr,
                    )
                })
                .expect("Host should return PartialFileLinesResult");

            if self.source_file.get().is_none() {
                if let Ok(p) = &partial_files {
                    if let Some(source_file) = &p.file {
                        self.source_file
                            .set(source_file.clone())
                            .expect("Should able to set source file");
                    }
                }
            }

            return partial_files.map(|files| FileLines {
                file: self
                    .source_file
                    .get()
                    .expect("SourceFile should exist")
                    .clone(),
                lines: files.lines,
            });
        }

        #[cfg(not(target_arch = "wasm32"))]
        unimplemented!("Sourcemap proxy cannot be called in this context")
    }

    fn span_to_string(&self, sp: Span) -> String {
        #[cfg(target_arch = "wasm32")]
        return read_returned_result_from_host(|serialized_ptr| unsafe {
            __span_to_string_proxy(sp.lo.0, sp.hi.0, serialized_ptr)
        })
        .expect("Host should return String");

        #[cfg(not(target_arch = "wasm32"))]
        unimplemented!("Sourcemap proxy cannot be called in this context")
    }

    fn span_to_filename(&self, sp: Span) -> Lrc<FileName> {
        #[cfg(target_arch = "wasm32")]
        return Lrc::new(
            read_returned_result_from_host(|serialized_ptr| unsafe {
                __span_to_filename_proxy(sp.lo.0, sp.hi.0, serialized_ptr)
            })
            .expect("Host should return Filename"),
        );

        #[cfg(not(target_arch = "wasm32"))]
        unimplemented!("Sourcemap proxy cannot be called in this context")
    }

    fn span_to_snippet(&self, sp: Span) -> Result<String, Box<SpanSnippetError>> {
        #[cfg(target_arch = "wasm32")]
        return self.span_to_source(sp, |src, start_index, end_index| {
            src[start_index..end_index].to_string()
        });

        #[cfg(not(target_arch = "wasm32"))]
        unimplemented!("Sourcemap proxy cannot be called in this context")
    }

    fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
        #[cfg(target_arch = "wasm32")]
        unsafe {
            // We need to `allocate` memory, force creates empty span instead of DUMMY_SP
            let span = Span {
                lo: BytePos(0),
                hi: BytePos(0),
            };

            let serialized = swc_common::plugin::serialized::PluginSerializedBytes::try_serialize(
                &swc_common::plugin::serialized::VersionedSerializable::new(span),
            )
            .expect("Should be serializable");
            let (ptr, len) = serialized.as_ptr();

            let ret =
                __merge_spans_proxy(sp_lhs.lo.0, sp_lhs.hi.0, sp_rhs.lo.0, sp_rhs.hi.0, ptr as _);

            return if ret == 1 { Some(span) } else { None };
        };

        #[cfg(not(target_arch = "wasm32"))]
        unimplemented!("Sourcemap proxy cannot be called in this context")
    }

    fn call_span_if_macro(&self, sp: Span) -> Span {
        // This mimics host's behavior
        // https://github.com/swc-project/swc/blob/f7dc3fff1f03c9b7cee27ef760dc11bc96083f60/crates/swc_common/src/source_map.rs#L1283-L1285=
        sp
    }

    fn doctest_offset_line(&self, line: usize) -> usize {
        #[cfg(target_arch = "wasm32")]
        unsafe {
            return __doctest_offset_line_proxy(line as u32) as usize;
        };

        #[cfg(not(target_arch = "wasm32"))]
        unimplemented!("Sourcemap proxy cannot be called in this context")
    }
}

#[cfg(feature = "__plugin_mode")]
impl SourceMapperExt for PluginSourceMapProxy {
    fn get_code_map(&self) -> &dyn SourceMapper {
        self
    }
}