use std::str::FromStr;

use anyhow::Result;
use kcmc::{
    ImportFile, ModelingCmd,
    coord::{KITTYCAD, System},
    each_cmd as mcmd,
    format::InputFormat3d,
    shared::FileImportFormat,
    units::UnitLength,
};
use kittycad_modeling_cmds as kcmc;
use serde::{Deserialize, Serialize};
use uuid::Uuid;

use crate::{
    errors::{KclError, KclErrorDetails},
    execution::{
        ExecState, ExecutorContext, ImportedGeometry, ModelingCmdMeta, annotations, typed_path::TypedPath,
        types::UnitLen,
    },
    fs::FileSystem,
    parsing::ast::types::{Annotation, Node},
    source_range::SourceRange,
};

// Zoo co-ordinate system.
//
// * Forward: -Y
// * Up: +Z
// * Handedness: Right
pub const ZOO_COORD_SYSTEM: System = *KITTYCAD;

pub async fn import_foreign(
    file_path: &TypedPath,
    format: Option<InputFormat3d>,
    exec_state: &mut ExecState,
    ctxt: &ExecutorContext,
    source_range: SourceRange,
) -> Result<PreImportedGeometry, KclError> {
    // Make sure the file exists.
    if !ctxt.fs.exists(file_path, source_range).await? {
        return Err(KclError::new_semantic(KclErrorDetails::new(
            format!("File `{}` does not exist.", file_path.display()),
            vec![source_range],
        )));
    }

    let ext_format = get_import_format_from_extension(file_path.extension().ok_or_else(|| {
        KclError::new_semantic(KclErrorDetails::new(
            format!("No file extension found for `{}`", file_path.display()),
            vec![source_range],
        ))
    })?)
    .map_err(|e| KclError::new_semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;

    // Get the format type from the extension of the file.
    let format = if let Some(format) = format {
        // Validate the given format with the extension format.
        validate_extension_format(ext_format, format.clone())
            .map_err(|e| KclError::new_semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;
        format
    } else {
        ext_format
    };

    // Get the file contents for each file path.
    let file_contents = ctxt
        .fs
        .read(file_path, source_range)
        .await
        .map_err(|e| KclError::new_semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;

    // We want the file_path to be without the parent.
    let file_name = file_path.file_name().map(|p| p.to_string()).ok_or_else(|| {
        KclError::new_semantic(KclErrorDetails::new(
            format!("Could not get the file name from the path `{}`", file_path.display()),
            vec![source_range],
        ))
    })?;
    let mut import_files = vec![kcmc::ImportFile {
        path: file_name.to_string(),
        data: file_contents.clone(),
    }];

    // In the case of a gltf importing a bin file we need to handle that! and figure out where the
    // file is relative to our current file.
    if let InputFormat3d::Gltf(..) = format {
        // Check if the file is a binary gltf file, in that case we don't need to import the bin
        // file.
        if !file_contents.starts_with(b"glTF") {
            let json = gltf_json::Root::from_slice(&file_contents)
                .map_err(|e| KclError::new_semantic(KclErrorDetails::new(e.to_string(), vec![source_range])))?;

            // Read the gltf file and check if there is a bin file.
            for buffer in json.buffers.iter() {
                if let Some(uri) = &buffer.uri {
                    if !uri.starts_with("data:") {
                        // We want this path relative to the file_path given.
                        let bin_path = file_path.parent().map(|p| p.join(uri)).ok_or_else(|| {
                            KclError::new_semantic(KclErrorDetails::new(
                                format!("Could not get the parent path of the file `{}`", file_path.display()),
                                vec![source_range],
                            ))
                        })?;

                        let bin_contents = ctxt.fs.read(&bin_path, source_range).await.map_err(|e| {
                            KclError::new_semantic(KclErrorDetails::new(e.to_string(), vec![source_range]))
                        })?;

                        import_files.push(ImportFile {
                            path: uri.to_string(),
                            data: bin_contents,
                        });
                    }
                }
            }
        }
    }
    Ok(PreImportedGeometry {
        id: exec_state.next_uuid(),
        source_range,
        command: mcmd::ImportFiles {
            files: import_files.clone(),
            format,
        },
    })
}

pub(super) fn format_from_annotations(
    annotations: &[Node<Annotation>],
    path: &TypedPath,
    import_source_range: SourceRange,
) -> Result<Option<InputFormat3d>, KclError> {
    if annotations.is_empty() {
        return Ok(None);
    }

    let props = annotations.iter().flat_map(|a| a.properties.as_deref().unwrap_or(&[]));

    let mut result = None;
    for p in props.clone() {
        if p.key.name == annotations::IMPORT_FORMAT {
            result = Some(
                get_import_format_from_extension(annotations::expect_ident(&p.value)?).map_err(|_| {
                    KclError::new_semantic(KclErrorDetails::new(
                        format!(
                            "Unknown format for import, expected one of: {}",
                            crate::IMPORT_FILE_EXTENSIONS.join(", ")
                        ),
                        vec![p.as_source_range()],
                    ))
                })?,
            );
            break;
        }
    }

    let mut result = result
        .or_else(|| {
            path.extension()
                .and_then(|ext| get_import_format_from_extension(ext).ok())
        })
        .ok_or(KclError::new_semantic(KclErrorDetails::new(
            "Unknown or missing extension, and no specified format for imported file".to_owned(),
            vec![import_source_range],
        )))?;

    for p in props {
        match p.key.name.as_str() {
            annotations::IMPORT_COORDS => {
                set_coords(&mut result, annotations::expect_ident(&p.value)?, p.as_source_range())?;
            }
            annotations::IMPORT_LENGTH_UNIT => {
                set_length_unit(&mut result, annotations::expect_ident(&p.value)?, p.as_source_range())?;
            }
            annotations::IMPORT_FORMAT => {}
            _ => {
                return Err(KclError::new_semantic(KclErrorDetails::new(
                    format!(
                        "Unexpected annotation for import, expected one of: {}, {}, {}",
                        annotations::IMPORT_FORMAT,
                        annotations::IMPORT_COORDS,
                        annotations::IMPORT_LENGTH_UNIT
                    ),
                    vec![p.as_source_range()],
                )));
            }
        }
    }

    Ok(Some(result))
}

fn set_coords(fmt: &mut InputFormat3d, coords_str: &str, source_range: SourceRange) -> Result<(), KclError> {
    let mut coords = None;
    for (name, val) in annotations::IMPORT_COORDS_VALUES {
        if coords_str == name {
            coords = Some(*val);
        }
    }

    let Some(coords) = coords else {
        return Err(KclError::new_semantic(KclErrorDetails::new(
            format!(
                "Unknown coordinate system: {coords_str}, expected one of: {}",
                annotations::IMPORT_COORDS_VALUES
                    .iter()
                    .map(|(n, _)| *n)
                    .collect::<Vec<_>>()
                    .join(", ")
            ),
            vec![source_range],
        )));
    };

    match fmt {
        InputFormat3d::Obj(opts) => opts.coords = coords,
        InputFormat3d::Ply(opts) => opts.coords = coords,
        InputFormat3d::Stl(opts) => opts.coords = coords,
        _ => {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                format!(
                    "`{}` option cannot be applied to the specified format",
                    annotations::IMPORT_COORDS
                ),
                vec![source_range],
            )));
        }
    }

    Ok(())
}

fn set_length_unit(fmt: &mut InputFormat3d, units_str: &str, source_range: SourceRange) -> Result<(), KclError> {
    let units = UnitLen::from_str(units_str, source_range)?;

    match fmt {
        InputFormat3d::Obj(opts) => opts.units = units.into(),
        InputFormat3d::Ply(opts) => opts.units = units.into(),
        InputFormat3d::Stl(opts) => opts.units = units.into(),
        _ => {
            return Err(KclError::new_semantic(KclErrorDetails::new(
                format!(
                    "`{}` option cannot be applied to the specified format",
                    annotations::IMPORT_LENGTH_UNIT
                ),
                vec![source_range],
            )));
        }
    }

    Ok(())
}

#[derive(Debug, Clone, PartialEq, Deserialize, Serialize)]
pub struct PreImportedGeometry {
    id: Uuid,
    command: mcmd::ImportFiles,
    pub source_range: SourceRange,
}

pub async fn send_to_engine(
    pre: PreImportedGeometry,
    exec_state: &mut ExecState,
    ctxt: &ExecutorContext,
) -> Result<ImportedGeometry, KclError> {
    let imported_geometry = ImportedGeometry::new(
        pre.id,
        pre.command.files.iter().map(|f| f.path.to_string()).collect(),
        vec![pre.source_range.into()],
    );

    exec_state
        .async_modeling_cmd(
            ModelingCmdMeta::with_id(ctxt, pre.source_range, pre.id),
            &ModelingCmd::from(pre.command.clone()),
        )
        .await?;

    Ok(imported_geometry)
}

/// Get the source format from the extension.
fn get_import_format_from_extension(ext: &str) -> Result<InputFormat3d> {
    let format = match FileImportFormat::from_str(ext) {
        Ok(format) => format,
        Err(_) => {
            if ext == "stp" {
                FileImportFormat::Step
            } else if ext == "glb" {
                FileImportFormat::Gltf
            } else {
                anyhow::bail!(
                    "unknown source format for file extension: {ext}. Try setting the `--src-format` flag explicitly or use a valid format."
                )
            }
        }
    };

    // Make the default units millimeters.
    let ul = UnitLength::Millimeters;

    // Zoo co-ordinate system.
    //
    // * Forward: -Y
    // * Up: +Z
    // * Handedness: Right
    match format {
        FileImportFormat::Step => Ok(InputFormat3d::Step(kcmc::format::step::import::Options {
            split_closed_faces: false,
        })),
        FileImportFormat::Stl => Ok(InputFormat3d::Stl(kcmc::format::stl::import::Options {
            coords: ZOO_COORD_SYSTEM,
            units: ul,
        })),
        FileImportFormat::Obj => Ok(InputFormat3d::Obj(kcmc::format::obj::import::Options {
            coords: ZOO_COORD_SYSTEM,
            units: ul,
        })),
        FileImportFormat::Gltf => Ok(InputFormat3d::Gltf(kcmc::format::gltf::import::Options {})),
        FileImportFormat::Ply => Ok(InputFormat3d::Ply(kcmc::format::ply::import::Options {
            coords: ZOO_COORD_SYSTEM,
            units: ul,
        })),
        FileImportFormat::Fbx => Ok(InputFormat3d::Fbx(kcmc::format::fbx::import::Options {})),
        FileImportFormat::Sldprt => Ok(InputFormat3d::Sldprt(kcmc::format::sldprt::import::Options {
            split_closed_faces: false,
        })),
    }
}

fn validate_extension_format(ext: InputFormat3d, given: InputFormat3d) -> Result<()> {
    if let InputFormat3d::Stl(_) = ext {
        if let InputFormat3d::Stl(_) = given {
            return Ok(());
        }
    }

    if let InputFormat3d::Obj(_) = ext {
        if let InputFormat3d::Obj(_) = given {
            return Ok(());
        }
    }

    if let InputFormat3d::Ply(_) = ext {
        if let InputFormat3d::Ply(_) = given {
            return Ok(());
        }
    }

    if ext == given {
        return Ok(());
    }

    anyhow::bail!(
        "The given format does not match the file extension. Expected: `{}`, Given: `{}`",
        get_name_of_format(ext),
        get_name_of_format(given)
    )
}

fn get_name_of_format(type_: InputFormat3d) -> &'static str {
    match type_ {
        InputFormat3d::Fbx(_) => "fbx",
        InputFormat3d::Gltf(_) => "gltf",
        InputFormat3d::Obj(_) => "obj",
        InputFormat3d::Ply(_) => "ply",
        InputFormat3d::Sldprt(_) => "sldprt",
        InputFormat3d::Step(_) => "step",
        InputFormat3d::Stl(_) => "stl",
    }
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn annotations() {
        // no annotations
        assert!(
            format_from_annotations(&[], &TypedPath::from("../foo.txt"), SourceRange::default(),)
                .unwrap()
                .is_none()
        );

        // no format, no options
        let text = "@()\nimport '../foo.gltf' as foo";
        let parsed = crate::Program::parse_no_errs(text).unwrap().ast;
        let attrs = parsed.body[0].get_attrs();
        let fmt = format_from_annotations(attrs, &TypedPath::from("../foo.gltf"), SourceRange::default())
            .unwrap()
            .unwrap();
        assert_eq!(
            fmt,
            InputFormat3d::Gltf(kittycad_modeling_cmds::format::gltf::import::Options {})
        );

        // format, no options
        let text = "@(format = gltf)\nimport '../foo.txt' as foo";
        let parsed = crate::Program::parse_no_errs(text).unwrap().ast;
        let attrs = parsed.body[0].get_attrs();
        let fmt = format_from_annotations(attrs, &TypedPath::from("../foo.txt"), SourceRange::default())
            .unwrap()
            .unwrap();
        assert_eq!(
            fmt,
            InputFormat3d::Gltf(kittycad_modeling_cmds::format::gltf::import::Options {})
        );

        // format, no extension (wouldn't parse but might some day)
        let fmt = format_from_annotations(attrs, &TypedPath::from("../foo"), SourceRange::default())
            .unwrap()
            .unwrap();
        assert_eq!(
            fmt,
            InputFormat3d::Gltf(kittycad_modeling_cmds::format::gltf::import::Options {})
        );

        // format, options
        let text = "@(format = obj, coords = vulkan, lengthUnit = ft)\nimport '../foo.txt' as foo";
        let parsed = crate::Program::parse_no_errs(text).unwrap().ast;
        let attrs = parsed.body[0].get_attrs();
        let fmt = format_from_annotations(attrs, &TypedPath::from("../foo.txt"), SourceRange::default())
            .unwrap()
            .unwrap();
        assert_eq!(
            fmt,
            InputFormat3d::Obj(kittycad_modeling_cmds::format::obj::import::Options {
                coords: *kittycad_modeling_cmds::coord::VULKAN,
                units: kittycad_modeling_cmds::units::UnitLength::Feet,
            })
        );

        // no format, options
        let text = "@(coords = vulkan, lengthUnit = ft)\nimport '../foo.obj' as foo";
        let parsed = crate::Program::parse_no_errs(text).unwrap().ast;
        let attrs = parsed.body[0].get_attrs();
        let fmt = format_from_annotations(attrs, &TypedPath::from("../foo.obj"), SourceRange::default())
            .unwrap()
            .unwrap();
        assert_eq!(
            fmt,
            InputFormat3d::Obj(kittycad_modeling_cmds::format::obj::import::Options {
                coords: *kittycad_modeling_cmds::coord::VULKAN,
                units: kittycad_modeling_cmds::units::UnitLength::Feet,
            })
        );

        // err - format, options, but no options for specified format
        assert_annotation_error(
            "@(format = gltf, lengthUnit = ft)\nimport '../foo.txt' as foo",
            "../foo.txt",
            "`lengthUnit` option cannot be applied",
        );
        // err - no format, options, but no options for specified format
        assert_annotation_error(
            "@(lengthUnit = ft)\nimport '../foo.gltf' as foo",
            "../foo.gltf",
            "lengthUnit` option cannot be applied",
        );
        // err - bad option
        assert_annotation_error(
            "@(format = obj, coords = vulkan, lengthUni = ft)\nimport '../foo.txt' as foo",
            "../foo.txt",
            "Unexpected annotation",
        );
        // err - bad format
        assert_annotation_error(
            "@(format = foo)\nimport '../foo.txt' as foo",
            "../foo.txt",
            "Unknown format for import",
        );
        // err - bad coord value
        assert_annotation_error(
            "@(format = gltf, coords = north)\nimport '../foo.txt' as foo",
            "../foo.txt",
            "Unknown coordinate system",
        );
        // err - bad unit value
        assert_annotation_error(
            "@(format = gltf, lengthUnit = gallons)\nimport '../foo.txt' as foo",
            "../foo.txt",
            "Unexpected value for length units",
        );
    }

    #[track_caller]
    fn assert_annotation_error(src: &str, path: &str, expected: &str) {
        let parsed = crate::Program::parse_no_errs(src).unwrap().ast;
        let attrs = parsed.body[0].get_attrs();
        let err = format_from_annotations(attrs, &TypedPath::from(path), SourceRange::default()).unwrap_err();
        assert!(
            err.message().contains(expected),
            "Expected: `{expected}`, found `{}`",
            err.message()
        );
    }
}