use std::path;

use itertools::Itertools;
use thiserror::Error;

use crate::{
    converter, generator,
    io::{get_xml_gitinfo, XmlGitInfoError},
    types, validator,
};

#[derive(Debug, Error)]
pub enum Error {
    #[error("error in getting xml git info: {0}")]
    XmlGitInfoError(#[from] XmlGitInfoError),
    #[error("io error: {0}")]
    IOError(#[from] std::io::Error),
    #[error("xml parse error: {0}")]
    XmlParseError(#[from] roxmltree::Error),
    #[error("dom conversion error: {0}")]
    DomConversionError(#[from] converter::DomConversionError),
    #[error("invalid register map:\n{}", ._0.iter().map(|e| e.to_string()).join("\n"))]
    RegmapValidationError(Vec<validator::ValidationError>),
    #[error("code generation error: {0}")]
    CodeGenError(#[from] generator::CodeGenError),
    #[cfg(feature = "flatmap")]
    #[error("csv write error: {0}")]
    CsvWriteError(#[from] csv::Error),
}

/// Generate register interface code from xml in `xml` and write them under directory `out`.
pub fn generate(xml: &path::Path, out: &path::Path) -> Result<(), Error> {
    log::debug!("generate called: xml:{:?}, out: {:?}", xml, out);

    let xml_git_info = get_xml_gitinfo(xml)?;
    log::debug!("xml git info {xml_git_info:?}");

    let xmlfile = std::fs::read_to_string(xml)?;
    let doc = roxmltree::Document::parse_with_options(
        &xmlfile,
        roxmltree::ParsingOptions {
            allow_dtd: true,
            nodes_limit: u32::MAX,
        },
    )?;
    log::debug!("xml parsed {doc:?}");

    let register_map = types::Module::from_xml_dom(doc.root_element(), xml_git_info)?;
    log::debug!("converted {register_map:?}");

    let (_maps, errors) = register_map.validate();
    if !errors.is_empty() {
        return Err(Error::RegmapValidationError(errors));
    }

    let files = register_map.generate_code()?;
    if log::log_enabled!(log::Level::Debug) {
        for (path, code) in &files {
            log::debug!("path: {:?}", path);
            log::debug!("{}", prettyplease::unparse(code));
            log::trace!("{}", prettyplease::unparse(code));
        }
    }

    crate::write_to_files(files, out)?;
    log::debug!("wrote to files");

    Ok(())
}

#[cfg(feature = "flatmap")]
pub fn generate_flatmap(xml: &path::Path, out: Option<&path::Path>) -> Result<(), Error> {
    use std::{
        fs::File,
        io::{self, BufWriter, Write},
    };

    log::debug!("generate called: xml:{:?}, out: {:?}", xml, out);

    let xml_git_info = get_xml_gitinfo(xml)?;
    log::debug!("xml git info {xml_git_info:?}");

    let xmlfile = std::fs::read_to_string(xml)?;
    let doc = roxmltree::Document::parse_with_options(
        &xmlfile,
        roxmltree::ParsingOptions {
            allow_dtd: true,
            nodes_limit: u32::MAX,
        },
    )?;
    log::debug!("xml parsed {doc:?}");

    let register_map = types::Module::from_xml_dom(doc.root_element(), xml_git_info)?;
    log::debug!("converted {register_map:?}");

    let (maps, errors) = register_map.validate();
    if !errors.is_empty() {
        return Err(Error::RegmapValidationError(errors));
    }
    let f: Box<dyn Write> = match out {
        Some(f) => {
            let file = File::options().write(true).truncate(true).open(f)?;
            Box::new(BufWriter::new(file))
        }
        None => Box::new(io::stdout()),
    };
    let mut wtr = csv::Writer::from_writer(f);

    wtr.write_record([
        "address",
        "path",
        "name",
        "multiple_id",
        "modf",
        "description",
    ])?;
    for (addr, reg) in maps.iter().enumerate() {
        match reg {
            Some(reg) => {
                let path = reg.0.join("/");
                let multiple_id = reg.2.map_or("".to_string(), |x| x.to_string());
                wtr.write_record([
                    format!("0x{:04x}", addr),
                    path,
                    reg.1.name.clone(),
                    multiple_id,
                    reg.1.modf.to_string(),
                    reg.1.desc.as_ref().unwrap_or(&"".to_string()).to_string(),
                ])?;
            }
            None => wtr.write_record([
                format!("0x{:04x}", addr),
                "".to_string(),
                "".to_string(),
                "".to_string(),
                "".to_string(),
                "".to_string(),
            ])?,
        }
    }
    Ok(())
}