import std::map::hashmap;
import middle::ty;
import middle::ty::*;
import metadata::encoder;
import syntax::codemap;
import syntax::print::pprust;
import syntax::print::pprust::{path_to_str, constr_args_to_str, proto_to_str,
                               mode_to_str};
import syntax::{ast, ast_util};
import syntax::ast_map;
import driver::session::session;

fn bound_region_to_str(cx: ctxt, br: bound_region) -> str {
    alt br {
      br_anon                        { "&" }
      br_named(str)                  { #fmt["&%s", str] }
      br_self if cx.sess.ppregions() { "&<self>" }
      br_self                        { "&self" }
    }
}

fn re_scope_id_to_str(cx: ctxt, node_id: ast::node_id) -> str {
    alt cx.items.get(node_id) {
      ast_map::node_block(blk) {
        #fmt("<block at %s>",
             codemap::span_to_str(blk.span, cx.sess.codemap))
      }
      ast_map::node_expr(expr) {
        alt expr.node {
          ast::expr_call(_, _, _) {
            #fmt("<call at %s>",
                 codemap::span_to_str(expr.span, cx.sess.codemap))
          }
          ast::expr_alt(_, _, _) {
            #fmt("<alt at %s>",
                 codemap::span_to_str(expr.span, cx.sess.codemap))
          }
          _ { cx.sess.bug(
              #fmt["re_scope refers to %s",
                   ast_map::node_id_to_str(cx.items, node_id)]) }
        }
      }
      _ { cx.sess.bug(
          #fmt["re_scope refers to %s",
               ast_map::node_id_to_str(cx.items, node_id)]) }
    }
}

fn region_to_str(cx: ctxt, region: region) -> str {
    alt region {
      re_scope(node_id) { #fmt["&%s", re_scope_id_to_str(cx, node_id)] }
      re_bound(br) { bound_region_to_str(cx, br) }
      re_free(id, br) {
        if cx.sess.ppregions() {
            // For debugging, this version is sometimes helpful:
            #fmt["{%d} %s", id, bound_region_to_str(cx, br)]
        } else {
            // But this version is what the user expects to see:
            bound_region_to_str(cx, br)
        }
      }

      // These two should not be seen by end-users (very often, anyhow):
      re_var(id)    { #fmt("&%s", id.to_str()) }
      re_static     { "&static" }
    }
}

fn mt_to_str(cx: ctxt, m: mt) -> str {
    let mstr = alt m.mutbl {
      ast::m_mutbl { "mut " }
      ast::m_imm { "" }
      ast::m_const { "const " }
    };
    ret mstr + ty_to_str(cx, m.ty);
}

fn vstore_to_str(cx: ctxt, vs: ty::vstore) -> str {
    alt vs {
      ty::vstore_fixed(n) { #fmt["%u", n] }
      ty::vstore_uniq { "~" }
      ty::vstore_box { "@" }
      ty::vstore_slice(r) { region_to_str(cx, r) }
    }
}

fn tys_to_str(cx: ctxt, ts: [t]) -> str {
    let mut rs = "";
    for ts.each {|t| rs += ty_to_str(cx, t); }
    rs
}

fn ty_to_str(cx: ctxt, typ: t) -> str {
    fn fn_input_to_str(cx: ctxt, input: {mode: ast::mode, ty: t}) ->
       str {
        let {mode, ty} = input;
        let modestr = alt canon_mode(cx, mode) {
          ast::infer(_) { "" }
          ast::expl(m) {
            if !ty::type_needs_infer(ty) &&
                m == ty::default_arg_mode_for_ty(ty) {
                ""
            } else {
                mode_to_str(ast::expl(m))
            }
          }
        };
        modestr + ty_to_str(cx, ty)
    }
    fn fn_to_str(cx: ctxt, proto: ast::proto, ident: option<ast::ident>,
                 inputs: [arg], output: t, cf: ast::ret_style,
                 constrs: [@constr]) -> str {
        let mut s = proto_to_str(proto);
        alt ident { some(i) { s += " "; s += i; } _ { } }
        s += "(";
        let mut strs = [];
        for inputs.each {|a| strs += [fn_input_to_str(cx, a)]; }
        s += str::connect(strs, ", ");
        s += ")";
        if ty::get(output).struct != ty_nil {
            s += " -> ";
            alt cf {
              ast::noreturn { s += "!"; }
              ast::return_val { s += ty_to_str(cx, output); }
            }
        }
        s += constrs_str(constrs);
        ret s;
    }
    fn method_to_str(cx: ctxt, m: method) -> str {
        ret fn_to_str(cx, m.fty.proto, some(m.ident), m.fty.inputs,
                      m.fty.output, m.fty.ret_style, m.fty.constraints) + ";";
    }
    fn field_to_str(cx: ctxt, f: field) -> str {
        ret f.ident + ": " + mt_to_str(cx, f.mt);
    }

    // if there is an id, print that instead of the structural type:
    for ty::type_def_id(typ).each { |def_id|
        // note that this typedef cannot have type parameters
        ret ast_map::path_to_str(ty::item_path(cx, def_id));
    }

    // pretty print the structural type representation:
    ret alt ty::get(typ).struct {
      ty_nil { "()" }
      ty_bot { "_|_" }
      ty_bool { "bool" }
      ty_int(ast::ty_i) { "int" }
      ty_int(ast::ty_char) { "char" }
      ty_int(t) { ast_util::int_ty_to_str(t) }
      ty_uint(ast::ty_u) { "uint" }
      ty_uint(t) { ast_util::uint_ty_to_str(t) }
      ty_float(ast::ty_f) { "float" }
      ty_float(t) { ast_util::float_ty_to_str(t) }
      ty_str { "str" }
      ty_box(tm) { "@" + mt_to_str(cx, tm) }
      ty_uniq(tm) { "~" + mt_to_str(cx, tm) }
      ty_ptr(tm) { "*" + mt_to_str(cx, tm) }
      ty_rptr(r, tm) {
        let rs = region_to_str(cx, r);
        if str::len(rs) == 1u {
            rs + mt_to_str(cx, tm)
        } else {
            rs + "." + mt_to_str(cx, tm)
        }
      }
      ty_vec(tm) { "[" + mt_to_str(cx, tm) + "]" }
      ty_type { "type" }
      ty_rec(elems) {
        let mut strs: [str] = [];
        for elems.each {|fld| strs += [field_to_str(cx, fld)]; }
        "{" + str::connect(strs, ",") + "}"
      }
      ty_tup(elems) {
        let mut strs = [];
        for elems.each {|elem| strs += [ty_to_str(cx, elem)]; }
        "(" + str::connect(strs, ",") + ")"
      }
      ty_fn(f) {
        fn_to_str(cx, f.proto, none, f.inputs, f.output, f.ret_style,
                  f.constraints)
      }
      ty_var(v) { v.to_str() }
      ty_param(id, _) {
        "'" + str::from_bytes([('a' as u8) + (id as u8)])
      }
      ty_self { "self" }
      ty_enum(did, substs) | ty_res(did, _, substs) | ty_class(did, substs) {
        let path = ty::item_path(cx, did);
        let base = ast_map::path_to_str(path);
        parameterized(cx, base, substs.self_r, substs.tps)
      }
      ty_iface(did, substs) {
        let path = ty::item_path(cx, did);
        let base = ast_map::path_to_str(path);
        parameterized(cx, base, substs.self_r, substs.tps)
      }
      ty_evec(mt, vs) {
        #fmt["[%s]/%s", mt_to_str(cx, mt),
             vstore_to_str(cx, vs)]
      }
      ty_estr(vs) { #fmt["str/%s", vstore_to_str(cx, vs)] }
      ty_opaque_box { "@?" }
      ty_constr(t, _) { "@?" }
      ty_opaque_closure_ptr(ck_block) { "closure&" }
      ty_opaque_closure_ptr(ck_box) { "closure@" }
      ty_opaque_closure_ptr(ck_uniq) { "closure~" }
    }
}

fn parameterized(cx: ctxt,
                 base: str,
                 self_r: option<ty::region>,
                 tps: [ty::t]) -> str {

    let r_str = alt self_r {
      none { "" }
      some(r) {
        #fmt["/%s", region_to_str(cx, r)]
      }
    };

    if vec::len(tps) > 0u {
        let strs = vec::map(tps, {|t| ty_to_str(cx, t)});
        #fmt["%s%s<%s>", base, r_str, str::connect(strs, ",")]
    } else {
        #fmt["%s%s", base, r_str]
    }
}

fn ty_to_short_str(cx: ctxt, typ: t) -> str {
    let mut s = encoder::encoded_ty(cx, typ);
    if str::len(s) >= 32u { s = str::slice(s, 0u, 32u); }
    ret s;
}

fn constr_to_str(c: @constr) -> str {
    ret path_to_str(c.node.path) +
            pprust::constr_args_to_str(pprust::uint_to_str, c.node.args);
}

fn constrs_str(constrs: [@constr]) -> str {
    let mut s = "";
    let mut colon = true;
    for constrs.each {|c|
        if colon { s += " : "; colon = false; } else { s += ", "; }
        s += constr_to_str(c);
    }
    ret s;
}

fn ty_constr_to_str<Q>(c: @ast::spanned<ast::constr_general_<@ast::path, Q>>)
   -> str {
    ret path_to_str(c.node.path) +
            constr_args_to_str::<@ast::path>(path_to_str, c.node.args);
}

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