use crate::commands::UnevaluatedCallInfo;
use crate::context::SpanSource;
use crate::errors::ShellError;
use crate::object::Value;
use crate::parser::hir::SyntaxType;
use crate::parser::registry::Signature;
use crate::prelude::*;
use mime::Mime;
use std::path::{Path, PathBuf};
use std::str::FromStr;
use surf::mime;
use uuid::Uuid;
pub struct Open;

impl PerItemCommand for Open {
    fn name(&self) -> &str {
        "open"
    }

    fn signature(&self) -> Signature {
        Signature::build(self.name())
            .required("path", SyntaxType::Path)
            .switch("raw")
    }

    fn usage(&self) -> &str {
        "Load a file into a cell, convert to table if possible (avoid by appending '--raw')"
    }

    fn run(
        &self,
        call_info: &CallInfo,
        registry: &CommandRegistry,
        raw_args: &RawCommandArgs,
        _input: Tagged<Value>,
    ) -> Result<OutputStream, ShellError> {
        run(call_info, registry, raw_args)
    }
}

fn run(
    call_info: &CallInfo,
    registry: &CommandRegistry,
    raw_args: &RawCommandArgs,
) -> Result<OutputStream, ShellError> {
    let shell_manager = &raw_args.shell_manager;
    let cwd = PathBuf::from(shell_manager.path());
    let full_path = PathBuf::from(cwd);

    let path = match call_info
        .args
        .nth(0)
        .ok_or_else(|| ShellError::string(&format!("No file or directory specified")))?
    {
        file => file,
    };
    let path_buf = path.as_path()?;
    let path_str = path_buf.display().to_string();
    let path_span = path.span();
    let has_raw = call_info.args.has("raw");
    let registry = registry.clone();
    let raw_args = raw_args.clone();

    let stream = async_stream_block! {

        let result = fetch(&full_path, &path_str, path_span).await;

        if let Err(e) = result {
            yield Err(e);
            return;
        }
        let (file_extension, contents, contents_tag, span_source) = result.unwrap();

        let file_extension = if has_raw {
            None
        } else {
            // If the extension could not be determined via mimetype, try to use the path
            // extension. Some file types do not declare their mimetypes (such as bson files).
            file_extension.or(path_str.split('.').last().map(String::from))
        };

        if let Some(uuid) = contents_tag.origin {
            // If we have loaded something, track its source
            yield ReturnSuccess::action(CommandAction::AddSpanSource(
                uuid,
                span_source,
            ));
        }

        let tagged_contents = contents.tagged(contents_tag);

        if let Some(extension) = file_extension {
            let command_name = format!("from-{}", extension);
            if let Some(converter) = registry.get_command(&command_name) {
                let new_args = RawCommandArgs {
                    host: raw_args.host,
                    shell_manager: raw_args.shell_manager,
                    call_info: UnevaluatedCallInfo {
                        args: crate::parser::hir::Call {
                            head: raw_args.call_info.args.head,
                            positional: None,
                            named: None
                        },
                        source: raw_args.call_info.source,
                        source_map: raw_args.call_info.source_map,
                        name_span: raw_args.call_info.name_span,
                    }
                };
                let mut result = converter.run(new_args.with_input(vec![tagged_contents]), &registry);
                let result_vec: Vec<Result<ReturnSuccess, ShellError>> = result.drain_vec().await;
                for res in result_vec {
                    match res {
                        Ok(ReturnSuccess::Value(Tagged { item: Value::List(list), ..})) => {
                            for l in list {
                                yield Ok(ReturnSuccess::Value(l));
                            }
                        }
                        Ok(ReturnSuccess::Value(Tagged { item, .. })) => {
                            yield Ok(ReturnSuccess::Value(Tagged { item, tag: contents_tag }));
                        }
                        x => yield x,
                    }
                }
            } else {
                yield ReturnSuccess::value(tagged_contents);
            }
        } else {
            yield ReturnSuccess::value(tagged_contents);
        }
    };

    Ok(stream.to_output_stream())
}

pub async fn fetch(
    cwd: &PathBuf,
    location: &str,
    span: Span,
) -> Result<(Option<String>, Value, Tag, SpanSource), ShellError> {
    let mut cwd = cwd.clone();
    if location.starts_with("http:") || location.starts_with("https:") {
        let response = surf::get(location).await;
        match response {
            Ok(mut r) => match r.headers().get("content-type") {
                Some(content_type) => {
                    let content_type = Mime::from_str(content_type).unwrap();
                    match (content_type.type_(), content_type.subtype()) {
                        (mime::APPLICATION, mime::XML) => Ok((
                            Some("xml".to_string()),
                            Value::string(r.body_string().await.map_err(|_| {
                                ShellError::labeled_error(
                                    "Could not load text from remote url",
                                    "could not load",
                                    span,
                                )
                            })?),
                            Tag {
                                span,
                                origin: Some(Uuid::new_v4()),
                            },
                            SpanSource::Url(location.to_string()),
                        )),
                        (mime::APPLICATION, mime::JSON) => Ok((
                            Some("json".to_string()),
                            Value::string(r.body_string().await.map_err(|_| {
                                ShellError::labeled_error(
                                    "Could not load text from remote url",
                                    "could not load",
                                    span,
                                )
                            })?),
                            Tag {
                                span,
                                origin: Some(Uuid::new_v4()),
                            },
                            SpanSource::Url(location.to_string()),
                        )),
                        (mime::APPLICATION, mime::OCTET_STREAM) => {
                            let buf: Vec<u8> = r.body_bytes().await.map_err(|_| {
                                ShellError::labeled_error(
                                    "Could not load binary file",
                                    "could not load",
                                    span,
                                )
                            })?;
                            Ok((
                                None,
                                Value::Binary(buf),
                                Tag {
                                    span,
                                    origin: Some(Uuid::new_v4()),
                                },
                                SpanSource::Url(location.to_string()),
                            ))
                        }
                        (mime::IMAGE, mime::SVG) => Ok((
                            Some("svg".to_string()),
                            Value::string(r.body_string().await.map_err(|_| {
                                ShellError::labeled_error(
                                    "Could not load svg from remote url",
                                    "could not load",
                                    span,
                                )
                            })?),
                            Tag {
                                span,
                                origin: Some(Uuid::new_v4()),
                            },
                            SpanSource::Url(location.to_string()),
                        )),
                        (mime::IMAGE, image_ty) => {
                            let buf: Vec<u8> = r.body_bytes().await.map_err(|_| {
                                ShellError::labeled_error(
                                    "Could not load image file",
                                    "could not load",
                                    span,
                                )
                            })?;
                            Ok((
                                Some(image_ty.to_string()),
                                Value::Binary(buf),
                                Tag {
                                    span,
                                    origin: Some(Uuid::new_v4()),
                                },
                                SpanSource::Url(location.to_string()),
                            ))
                        }
                        (mime::TEXT, mime::HTML) => Ok((
                            Some("html".to_string()),
                            Value::string(r.body_string().await.map_err(|_| {
                                ShellError::labeled_error(
                                    "Could not load text from remote url",
                                    "could not load",
                                    span,
                                )
                            })?),
                            Tag {
                                span,
                                origin: Some(Uuid::new_v4()),
                            },
                            SpanSource::Url(location.to_string()),
                        )),
                        (mime::TEXT, mime::PLAIN) => {
                            let path_extension = url::Url::parse(location)
                                .unwrap()
                                .path_segments()
                                .and_then(|segments| segments.last())
                                .and_then(|name| if name.is_empty() { None } else { Some(name) })
                                .and_then(|name| {
                                    PathBuf::from(name)
                                        .extension()
                                        .map(|name| name.to_string_lossy().to_string())
                                });

                            Ok((
                                path_extension,
                                Value::string(r.body_string().await.map_err(|_| {
                                    ShellError::labeled_error(
                                        "Could not load text from remote url",
                                        "could not load",
                                        span,
                                    )
                                })?),
                                Tag {
                                    span,
                                    origin: Some(Uuid::new_v4()),
                                },
                                SpanSource::Url(location.to_string()),
                            ))
                        }
                        (ty, sub_ty) => Ok((
                            None,
                            Value::string(format!(
                                "Not yet supported MIME type: {} {}",
                                ty, sub_ty
                            )),
                            Tag {
                                span,
                                origin: Some(Uuid::new_v4()),
                            },
                            SpanSource::Url(location.to_string()),
                        )),
                    }
                }
                None => Ok((
                    None,
                    Value::string(format!("No content type found")),
                    Tag {
                        span,
                        origin: Some(Uuid::new_v4()),
                    },
                    SpanSource::Url(location.to_string()),
                )),
            },
            Err(_) => {
                return Err(ShellError::labeled_error(
                    "URL could not be opened",
                    "url not found",
                    span,
                ));
            }
        }
    } else {
        cwd.push(Path::new(location));
        if let Ok(cwd) = dunce::canonicalize(cwd) {
            match std::fs::read(&cwd) {
                Ok(bytes) => match std::str::from_utf8(&bytes) {
                    Ok(s) => Ok((
                        cwd.extension()
                            .map(|name| name.to_string_lossy().to_string()),
                        Value::string(s),
                        Tag {
                            span,
                            origin: Some(Uuid::new_v4()),
                        },
                        SpanSource::File(cwd.to_string_lossy().to_string()),
                    )),
                    Err(_) => {
                        //Non utf8 data.
                        match (bytes.get(0), bytes.get(1)) {
                            (Some(x), Some(y)) if *x == 0xff && *y == 0xfe => {
                                // Possibly UTF-16 little endian
                                let utf16 = read_le_u16(&bytes[2..]);

                                if let Some(utf16) = utf16 {
                                    match std::string::String::from_utf16(&utf16) {
                                        Ok(s) => Ok((
                                            cwd.extension()
                                                .map(|name| name.to_string_lossy().to_string()),
                                            Value::string(s),
                                            Tag {
                                                span,
                                                origin: Some(Uuid::new_v4()),
                                            },
                                            SpanSource::File(cwd.to_string_lossy().to_string()),
                                        )),
                                        Err(_) => Ok((
                                            None,
                                            Value::Binary(bytes),
                                            Tag {
                                                span,
                                                origin: Some(Uuid::new_v4()),
                                            },
                                            SpanSource::File(cwd.to_string_lossy().to_string()),
                                        )),
                                    }
                                } else {
                                    Ok((
                                        None,
                                        Value::Binary(bytes),
                                        Tag {
                                            span,
                                            origin: Some(Uuid::new_v4()),
                                        },
                                        SpanSource::File(cwd.to_string_lossy().to_string()),
                                    ))
                                }
                            }
                            (Some(x), Some(y)) if *x == 0xfe && *y == 0xff => {
                                // Possibly UTF-16 big endian
                                let utf16 = read_be_u16(&bytes[2..]);

                                if let Some(utf16) = utf16 {
                                    match std::string::String::from_utf16(&utf16) {
                                        Ok(s) => Ok((
                                            cwd.extension()
                                                .map(|name| name.to_string_lossy().to_string()),
                                            Value::string(s),
                                            Tag {
                                                span,
                                                origin: Some(Uuid::new_v4()),
                                            },
                                            SpanSource::File(cwd.to_string_lossy().to_string()),
                                        )),
                                        Err(_) => Ok((
                                            None,
                                            Value::Binary(bytes),
                                            Tag {
                                                span,
                                                origin: Some(Uuid::new_v4()),
                                            },
                                            SpanSource::File(cwd.to_string_lossy().to_string()),
                                        )),
                                    }
                                } else {
                                    Ok((
                                        None,
                                        Value::Binary(bytes),
                                        Tag {
                                            span,
                                            origin: Some(Uuid::new_v4()),
                                        },
                                        SpanSource::File(cwd.to_string_lossy().to_string()),
                                    ))
                                }
                            }
                            _ => Ok((
                                None,
                                Value::Binary(bytes),
                                Tag {
                                    span,
                                    origin: Some(Uuid::new_v4()),
                                },
                                SpanSource::File(cwd.to_string_lossy().to_string()),
                            )),
                        }
                    }
                },
                Err(_) => {
                    return Err(ShellError::labeled_error(
                        "File could not be opened",
                        "file not found",
                        span,
                    ));
                }
            }
        } else {
            return Err(ShellError::labeled_error(
                "File could not be opened",
                "file not found",
                span,
            ));
        }
    }
}

fn read_le_u16(input: &[u8]) -> Option<Vec<u16>> {
    if input.len() % 2 != 0 || input.len() < 2 {
        None
    } else {
        let mut result = vec![];
        let mut pos = 0;
        while pos < input.len() {
            result.push(u16::from_le_bytes([input[pos], input[pos + 1]]));
            pos += 2;
        }

        Some(result)
    }
}

fn read_be_u16(input: &[u8]) -> Option<Vec<u16>> {
    if input.len() % 2 != 0 || input.len() < 2 {
        None
    } else {
        let mut result = vec![];
        let mut pos = 0;
        while pos < input.len() {
            result.push(u16::from_be_bytes([input[pos], input[pos + 1]]));
            pos += 2;
        }

        Some(result)
    }
}