pub mod types;
pub mod names;
pub mod context;
pub mod parsers;
pub mod unparsers;
pub mod codegen;

use crate::gen::schema::*;
use crate::syntax::block::Formatter;
use crate::syntax::block::constructors::*;

use glob::glob;
use preserves::value::Map;
use preserves::value::PackedReader;
use preserves::value::Reader;
use preserves::value::Set;

use std::convert::TryFrom;
use std::fs::DirBuilder;
use std::fs::File;
use std::io::BufRead;
use std::io::BufReader;
use std::io::Error;
use std::io::ErrorKind;
use std::io::Write;
use std::path::PathBuf;

pub type ModulePath = Vec<String>;

#[derive(Debug)]
pub struct CompilerConfig {
    pub bundle: Map<ModulePath, Schema>,
    pub output_dir: PathBuf,
    pub fully_qualified_module_prefix: String,
    pub support_crate: String,
}

impl CompilerConfig {
    pub fn new(
        output_dir: PathBuf,
        fully_qualified_module_prefix: String,
    ) -> Self {
        CompilerConfig {
            bundle: Map::new(),
            output_dir: output_dir,
            fully_qualified_module_prefix: fully_qualified_module_prefix,
            support_crate: "preserves_schema".to_owned(),
        }
    }

    pub fn load_schemas_and_bundles(&mut self, inputs: &Vec<PathBuf>) -> Result<(), Error> {
        for i in inputs {
            let mut f = File::open(&i)?;
            let mut reader = PackedReader::decode_read(&mut f);
            let blob = reader.demand_next(false)?;

            if let Ok(s) = Schema::try_from(&blob) {
                let prefix = i.file_stem().ok_or_else(
                    || Error::new(ErrorKind::InvalidData, format!("Bad schema file stem: {:?}", i)))?
                    .to_str().ok_or_else(
                        || Error::new(ErrorKind::InvalidData, format!("Invalid UTF-8 in schema file name: {:?}", i)))?;
                self.bundle.insert(vec![prefix.to_owned()], s);
                return Ok(());
            }

            if let Ok(Bundle { modules }) = Bundle::try_from(&blob) {
                for (ModulePath(k), v) in modules.0 {
                    self.bundle.insert(k, v);
                }
                return Ok(());
            }

            return Err(Error::new(ErrorKind::InvalidData,
                                  format!("Invalid schema binary blob {:?}", i)));
        }
        Ok(())
    }
}

pub fn expand_inputs(globs: &Vec<String>) -> Result<Vec<PathBuf>, Error> {
    let mut result = Vec::new();
    for g in globs.iter() {
        for p in glob(g).map_err(|e| Error::new(ErrorKind::InvalidData, format!("{}", e)))? {
            result.push(p.map_err(glob::GlobError::into_error)?)
        }
    }
    Ok(result)
}

pub fn compile(config: &CompilerConfig) -> Result<(), std::io::Error> {
    for (k, v) in config.bundle.iter() {
        let mut output_path = config.output_dir.clone();
        output_path.extend(k);
        output_path.set_extension("rs");
        let module_name = output_path.file_stem().unwrap().to_str().unwrap().to_owned();
        DirBuilder::new().recursive(true).create(output_path.parent().unwrap())?;
        let mut m = context::ModuleContext::new(config);

        // TODO: embedded type

        for (n, d) in &v.definitions.0 {
            m.define_type(item(types::render_definition_type(&m, n, &types::definition_type(d))));
            parsers::gen_definition_parser(&mut m, n, d);
            unparsers::gen_definition_unparser(&mut m, n, d);
        }

        //---------------------------------------------------------------------------

        let mut lines: Vec<String> = Vec::new();

        lines.push("#![allow(unused_parens)]".to_owned());
        lines.push("".to_owned());
        lines.push("use std::convert::TryFrom;".to_owned());
        lines.push("use preserves::value::NestedValue;".to_owned());
        lines.push(format!("use {}::support::*;", &config.support_crate));
        lines.push("".to_owned());

        lines.push("lazy_static! {".to_owned());
        for (value, name) in m.literals {
            let bs = preserves::value::PackedWriter::encode(&value).unwrap();
            lines.push(format!("    pub static ref {}: preserves::value::IOValue = /* {:?} */ preserves::value::packed::from_bytes(&vec!{:?}).unwrap();",
                               name,
                               value,
                               bs));
        }
        lines.push("}".to_owned());
        lines.push("".to_owned());

        for i in m.typedefs {
            lines.push(Formatter::to_string(i));
            lines.push("".to_owned());
        }
        for i in m.functiondefs {
            lines.push(Formatter::to_string(i));
            lines.push("".to_owned());
        }

        {
            let mut f = File::create(&output_path)?;
            for line in lines {
                write!(f, "{}\n", line)?;
            }
        }

        {
            let mut mod_rs = output_path.clone();
            mod_rs.set_file_name("mod.rs");
            let mut lines = if !mod_rs.exists() {
                Set::new()
            } else {
                BufReader::new(File::open(&mod_rs)?)
                    .lines().collect::<Result<Set<String>, Error>>()?
            };
            lines.insert(format!("pub mod {};", &module_name));
            let mut f = File::create(mod_rs)?;
            for line in lines {
                write!(f, "{}\n", line)?;
            }
        }
    }
    Ok(())
}