// The crate store - a central repo for information collected about external
// crates and libraries

import std::{vec, map, str};
import syntax::ast;

export cstore;
export cnum_map;
export crate_metadata;
export mk_cstore;
export get_crate_data;
export set_crate_data;
export have_crate_data;
export iter_crate_data;
export add_used_crate_file;
export get_used_crate_files;
export add_used_library;
export get_used_libraries;
export add_used_link_args;
export get_used_link_args;
export add_use_stmt_cnum;
export get_use_stmt_cnum;

// A map from external crate numbers (as decoded from some crate file) to
// local crate numbers (as generated during this session). Each external
// crate may refer to types in other external crates, and each has their
// own crate numbers.
type cnum_map = map::hashmap<ast::crate_num, ast::crate_num>;

type crate_metadata = {name: str, data: @[u8], cnum_map: cnum_map};

// This is a bit of an experiment at encapsulating the data in cstore. By
// keeping all the data in a non-exported tag variant, it's impossible for
// other modules to access the cstore's private data. This could also be
// achieved with an obj, but at the expense of a vtable. Not sure if this is a
// good pattern or not.
tag cstore { private(cstore_private); }

type cstore_private =
    @{metas: map::hashmap<ast::crate_num, crate_metadata>,
      use_crate_map: use_crate_map,
      mutable used_crate_files: [str],
      mutable used_libraries: [str],
      mutable used_link_args: [str]};

// Map from node_id's of local use statements to crate numbers
type use_crate_map = map::hashmap<ast::node_id, ast::crate_num>;

// Internal method to retrieve the data from the cstore
fn p(cstore: cstore) -> cstore_private { alt cstore { private(p) { p } } }

fn mk_cstore() -> cstore {
    let meta_cache = map::new_int_hash::<crate_metadata>();
    let crate_map = map::new_int_hash::<ast::crate_num>();
    ret private(@{metas: meta_cache,
                  use_crate_map: crate_map,
                  mutable used_crate_files: [],
                  mutable used_libraries: [],
                  mutable used_link_args: []});
}

fn get_crate_data(cstore: cstore, cnum: ast::crate_num) -> crate_metadata {
    ret p(cstore).metas.get(cnum);
}

fn set_crate_data(cstore: cstore, cnum: ast::crate_num,
                  data: crate_metadata) {
    p(cstore).metas.insert(cnum, data);
}

fn have_crate_data(cstore: cstore, cnum: ast::crate_num) -> bool {
    ret p(cstore).metas.contains_key(cnum);
}

fn iter_crate_data(cstore: cstore, i: block(ast::crate_num, crate_metadata)) {
    p(cstore).metas.items {|k,v| i(k, v);};
}

fn add_used_crate_file(cstore: cstore, lib: str) {
    if !vec::member(lib, p(cstore).used_crate_files) {
        p(cstore).used_crate_files += [lib];
    }
}

fn get_used_crate_files(cstore: cstore) -> [str] {
    ret p(cstore).used_crate_files;
}

fn add_used_library(cstore: cstore, lib: str) -> bool {
    if lib == "" { ret false; }

    if vec::member(lib, p(cstore).used_libraries) { ret false; }

    p(cstore).used_libraries += [lib];
    ret true;
}

fn get_used_libraries(cstore: cstore) -> [str] {
    ret p(cstore).used_libraries;
}

fn add_used_link_args(cstore: cstore, args: str) {
    p(cstore).used_link_args += str::split(args, ' ' as u8);
}

fn get_used_link_args(cstore: cstore) -> [str] {
    ret p(cstore).used_link_args;
}

fn add_use_stmt_cnum(cstore: cstore, use_id: ast::node_id,
                     cnum: ast::crate_num) {
    p(cstore).use_crate_map.insert(use_id, cnum);
}

fn get_use_stmt_cnum(cstore: cstore, use_id: ast::node_id) -> ast::crate_num {
    ret p(cstore).use_crate_map.get(use_id);
}

// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End: