import std::map;
import std::map::hashmap;
import ast::*;
import print::pprust;
import ast_util::path_to_ident;
import ast_util::inlined_item_methods;
import diagnostic::span_handler;

enum path_elt { path_mod(ident), path_name(ident) }
type path = ~[path_elt];

/* FIXMEs that say "bad" are as per #2543 */
fn path_to_str_with_sep(p: path, sep: ~str) -> ~str {
    let strs = do vec::map(p) |e| {
        alt e {
          path_mod(s) { /* FIXME (#2543) */ copy *s }
          path_name(s) { /* FIXME (#2543) */ copy *s }
        }
    };
    str::connect(strs, sep)
}

fn path_ident_to_str(p: path, i: ident) -> ~str {
    if vec::is_empty(p) {
        /* FIXME (#2543) */ copy *i
    } else {
        #fmt["%s::%s", path_to_str(p), *i]
    }
}

fn path_to_str(p: path) -> ~str {
    path_to_str_with_sep(p, ~"::")
}

enum ast_node {
    node_item(@item, @path),
    node_foreign_item(@foreign_item, foreign_abi, @path),
    node_method(@method, def_id /* impl did */, @path /* path to the impl */),
    node_variant(variant, @item, @path),
    node_expr(@expr),
    node_export(@view_path, @path),
    // Locals are numbered, because the alias analysis needs to know in which
    // order they are introduced.
    node_arg(arg, uint),
    node_local(uint),
    // Constructor for a class
    // def_id is parent id
    node_ctor(ident, ~[ty_param], @class_ctor, def_id, @path),
    // Destructor for a class
    node_dtor(~[ty_param], @class_dtor, def_id, @path),
    node_block(blk),
}

type map = std::map::hashmap<node_id, ast_node>;
type ctx = {map: map, mut path: path,
            mut local_id: uint, diag: span_handler};
type vt = visit::vt<ctx>;

fn extend(cx: ctx, +elt: ident) -> @path {
    @(vec::append(cx.path, ~[path_name(elt)]))
}

fn mk_ast_map_visitor() -> vt {
    ret visit::mk_vt(@{
        visit_item: map_item,
        visit_expr: map_expr,
        visit_fn: map_fn,
        visit_local: map_local,
        visit_arm: map_arm,
        visit_view_item: map_view_item,
        visit_block: map_block
        with *visit::default_visitor()
    });
}

fn map_crate(diag: span_handler, c: crate) -> map {
    let cx = {map: std::map::int_hash(),
              mut path: ~[],
              mut local_id: 0u,
              diag: diag};
    visit::visit_crate(c, cx, mk_ast_map_visitor());
    ret cx.map;
}

// Used for items loaded from external crate that are being inlined into this
// crate.  The `path` should be the path to the item but should not include
// the item itself.
fn map_decoded_item(diag: span_handler,
                    map: map, +path: path, ii: inlined_item) {
    // I believe it is ok for the local IDs of inlined items from other crates
    // to overlap with the local ids from this crate, so just generate the ids
    // starting from 0.  (In particular, I think these ids are only used in
    // alias analysis, which we will not be running on the inlined items, and
    // even if we did I think it only needs an ordering between local
    // variables that are simultaneously in scope).
    let cx = {map: map,
              mut path: /* FIXME (#2543) */ copy path,
              mut local_id: 0u,
              diag: diag};
    let v = mk_ast_map_visitor();

    // methods get added to the AST map when their impl is visited.  Since we
    // don't decode and instantiate the impl, but just the method, we have to
    // add it to the table now:
    alt ii {
      ii_item(*) | ii_ctor(*) | ii_dtor(*) { /* fallthrough */ }
      ii_foreign(i) {
        cx.map.insert(i.id, node_foreign_item(i, foreign_abi_rust_intrinsic,
                                             @path));
      }
      ii_method(impl_did, m) {
        map_method(impl_did, @path, m, cx);
      }
    }

    // visit the item / method contents and add those to the map:
    ii.accept(cx, v);
}

fn map_fn(fk: visit::fn_kind, decl: fn_decl, body: blk,
          sp: codemap::span, id: node_id, cx: ctx, v: vt) {
    for decl.inputs.each |a| {
        cx.map.insert(a.id,
                      node_arg(/* FIXME (#2543) */
                          copy a, cx.local_id));
        cx.local_id += 1u;
    }
    alt fk {
      visit::fk_ctor(nm, attrs, tps, self_id, parent_id) {
          let ct = @{node: {id: id,
                            attrs: attrs,
                            self_id: self_id,
                            dec: /* FIXME (#2543) */ copy decl,
                            body: /* FIXME (#2543) */ copy body},
                    span: sp};
          cx.map.insert(id, node_ctor(/* FIXME (#2543) */ copy nm,
                                      /* FIXME (#2543) */ copy tps,
                                      ct, parent_id,
                                      @/* FIXME (#2543) */ copy cx.path));
      }
      visit::fk_dtor(tps, attrs, self_id, parent_id) {
          let dt = @{node: {id: id, attrs: attrs, self_id: self_id,
                     body: /* FIXME (#2543) */ copy body}, span: sp};
          cx.map.insert(id, node_dtor(/* FIXME (#2543) */ copy tps, dt,
                                      parent_id,
                                      @/* FIXME (#2543) */ copy cx.path));
      }
      _ {}
    }
    visit::visit_fn(fk, decl, body, sp, id, cx, v);
}

fn map_block(b: blk, cx: ctx, v: vt) {
    cx.map.insert(b.node.id, node_block(/* FIXME (#2543) */ copy b));
    visit::visit_block(b, cx, v);
}

fn number_pat(cx: ctx, pat: @pat) {
    do ast_util::walk_pat(pat) |p| {
        alt p.node {
          pat_ident(_, _) {
            cx.map.insert(p.id, node_local(cx.local_id));
            cx.local_id += 1u;
          }
          _ {}
        }
    };
}

fn map_local(loc: @local, cx: ctx, v: vt) {
    number_pat(cx, loc.node.pat);
    visit::visit_local(loc, cx, v);
}

fn map_arm(arm: arm, cx: ctx, v: vt) {
    number_pat(cx, arm.pats[0]);
    visit::visit_arm(arm, cx, v);
}

fn map_method(impl_did: def_id, impl_path: @path,
              m: @method, cx: ctx) {
    cx.map.insert(m.id, node_method(m, impl_did, impl_path));
    cx.map.insert(m.self_id, node_local(cx.local_id));
    cx.local_id += 1u;
}

fn map_item(i: @item, cx: ctx, v: vt) {
    let item_path = @/* FIXME (#2543) */ copy cx.path;
    cx.map.insert(i.id, node_item(i, item_path));
    alt i.node {
      item_impl(_, opt_ir, _, ms) {
        let impl_did = ast_util::local_def(i.id);
        for ms.each |m| {
            map_method(impl_did, extend(cx, i.ident), m,
                       cx);
        }
      }
      item_enum(vs, _) {
        for vs.each |v| {
            cx.map.insert(v.node.id, node_variant(
                /* FIXME (#2543) */ copy v, i,
                extend(cx, i.ident)));
        }
      }
      item_foreign_mod(nm) {
        let abi = alt attr::foreign_abi(i.attrs) {
          either::left(msg) { cx.diag.span_fatal(i.span, msg); }
          either::right(abi) { abi }
        };
        for nm.items.each |nitem| {
            cx.map.insert(nitem.id,
                          node_foreign_item(nitem, abi,
                                           /* FIXME (#2543) */
                                           extend(cx, i.ident)));
        }
      }
      item_class(tps, traits, items, ctor, dtor) {
          let (_, ms) = ast_util::split_class_items(items);
          // Map trait refs to their parent classes. This is
          // so we can find the self_ty
          do vec::iter(traits) |p| { cx.map.insert(p.ref_id,
                                  node_item(i, item_path));
                            // This is so we can look up the right things when
                            // encoding/decoding
                            cx.map.insert(p.impl_id,
                                          node_item(i, item_path));

                           };
          let d_id = ast_util::local_def(i.id);
          let p = extend(cx, i.ident);
           // only need to handle methods
          do vec::iter(ms) |m| { map_method(d_id, p, m, cx); }
      }
      _ { }
    }
    alt i.node {
      item_mod(_) | item_foreign_mod(_) {
        vec::push(cx.path, path_mod(i.ident));
      }
      _ { vec::push(cx.path, path_name(i.ident)); }
    }
    visit::visit_item(i, cx, v);
    vec::pop(cx.path);
}

fn map_view_item(vi: @view_item, cx: ctx, _v: vt) {
    alt vi.node {
      view_item_export(vps) {
        for vps.each |vp| {
            let (id, name) = alt vp.node {
              view_path_simple(nm, _, id) {
                (id, /* FIXME (#2543) */ copy nm)
              }
              view_path_glob(pth, id) | view_path_list(pth, _, id) {
                (id, path_to_ident(pth))
              }
            };
            cx.map.insert(id, node_export(vp, extend(cx, name)));
        }
      }
      _ {}
    }
}

fn map_expr(ex: @expr, cx: ctx, v: vt) {
    cx.map.insert(ex.id, node_expr(ex));
    visit::visit_expr(ex, cx, v);
}

fn node_id_to_str(map: map, id: node_id) -> ~str {
    alt map.find(id) {
      none {
        #fmt["unknown node (id=%d)", id]
      }
      some(node_item(item, path)) {
        #fmt["item %s (id=%?)", path_ident_to_str(*path, item.ident), id]
      }
      some(node_foreign_item(item, abi, path)) {
        #fmt["foreign item %s with abi %? (id=%?)",
             path_ident_to_str(*path, item.ident), abi, id]
      }
      some(node_method(m, impl_did, path)) {
        #fmt["method %s in %s (id=%?)",
             *m.ident, path_to_str(*path), id]
      }
      some(node_variant(variant, def_id, path)) {
        #fmt["variant %s in %s (id=%?)",
             *variant.node.name, path_to_str(*path), id]
      }
      some(node_expr(expr)) {
        #fmt["expr %s (id=%?)",
             pprust::expr_to_str(expr), id]
      }
      // FIXMEs are as per #2410
      some(node_export(_, path)) {
        #fmt["export %s (id=%?)", // add more info here
             path_to_str(*path), id]
      }
      some(node_arg(_, _)) { // add more info here
        #fmt["arg (id=%?)", id]
      }
      some(node_local(_)) { // add more info here
        #fmt["local (id=%?)", id]
      }
      some(node_ctor(*)) { // add more info here
        #fmt["node_ctor (id=%?)", id]
      }
      some(node_dtor(*)) { // add more info here
        #fmt["node_dtor (id=%?)", id]
      }
      some(node_block(_)) {
        #fmt["block"]
      }
    }
}
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End: