/*
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.

Author: Leonardo de Moura
*/
#include "operator_info.h"
#include "rc.h"

namespace lean {

struct operator_info::imp {
    void dealloc() { delete this;  }
    MK_LEAN_RC();
    fixity        m_fixity;
    unsigned      m_precedence;
    list<name>    m_op_parts;  // operator parts, > 1 only if the operator is mixfix.
    list<name>    m_names;     // internal names, > 1 only if the operator is overloaded.

    imp(name const & op, fixity f, unsigned p):
        m_rc(1), m_fixity(f), m_precedence(p), m_op_parts(cons(op, list<name>())) {}

    imp(unsigned num_parts, name const * parts, fixity f, unsigned p):
        m_rc(1), m_fixity(f), m_precedence(p), m_op_parts(it2list<name, name const *>(parts, parts + num_parts)) {
        lean_assert(num_parts > 0);
    }

    imp(imp const & s):
        m_rc(1), m_fixity(s.m_fixity), m_precedence(s.m_precedence), m_op_parts(s.m_op_parts), m_names(s.m_names) {
    }

    bool is_eq(imp const & other) const {
        return
            m_fixity == other.m_fixity &&
            m_precedence == other.m_precedence &&
            m_op_parts == other.m_op_parts;
    }

};

operator_info::operator_info(imp * p):m_ptr(p) {}

operator_info::operator_info(operator_info const & info):m_ptr(info.m_ptr) { if (m_ptr) m_ptr->inc_ref(); }

operator_info::operator_info(operator_info && info):m_ptr(info.m_ptr) { info.m_ptr = nullptr; }

operator_info::~operator_info() { if (m_ptr) m_ptr->dec_ref(); }

operator_info & operator_info::operator=(operator_info const & s) { LEAN_COPY_REF(operator_info, s); }

operator_info & operator_info::operator=(operator_info && s) { LEAN_MOVE_REF(operator_info, s); }

void operator_info::add_internal_name(name const & n) { lean_assert(m_ptr); m_ptr->m_names = cons(n, m_ptr->m_names); }

bool operator_info::is_overloaded() const { return m_ptr && !is_nil(m_ptr->m_names) && !is_nil(cdr(m_ptr->m_names)); }

list<name> const & operator_info::get_internal_names() const { lean_assert(m_ptr); return m_ptr->m_names; }

fixity operator_info::get_fixity() const { lean_assert(m_ptr); return m_ptr->m_fixity; }

unsigned operator_info::get_precedence() const { lean_assert(m_ptr); return m_ptr->m_precedence; }

name const & operator_info::get_op_name() const { lean_assert(m_ptr); return car(m_ptr->m_op_parts); }

list<name> const & operator_info::get_op_name_parts() const { lean_assert(m_ptr); return m_ptr->m_op_parts; }

operator_info operator_info::copy() const { return operator_info(new imp(*m_ptr)); }

bool operator==(operator_info const & op1, operator_info const & op2) {
    if ((op1.m_ptr == nullptr) != (op2.m_ptr == nullptr))
        return false;
    if (op1.m_ptr)
        return op1.m_ptr->is_eq(*(op2.m_ptr));
    else
        return true;
}

operator_info infixr(name const & op, unsigned precedence) {
    return operator_info(new operator_info::imp(op, fixity::Infixr, precedence));
}
operator_info infixl(name const & op, unsigned precedence) {
    return operator_info(new operator_info::imp(op, fixity::Infixl, precedence));
}
operator_info prefix(name const & op, unsigned precedence) {
    return operator_info(new operator_info::imp(op, fixity::Prefix, precedence));
}
operator_info postfix(name const & op, unsigned precedence) {
    return operator_info(new operator_info::imp(op, fixity::Postfix, precedence));
}
operator_info mixfixl(unsigned num_parts, name const * parts, unsigned precedence) {
    lean_assert(num_parts > 1); return operator_info(new operator_info::imp(num_parts, parts, fixity::Mixfixl, precedence));
}
operator_info mixfixr(unsigned num_parts, name const * parts, unsigned precedence) {
    lean_assert(num_parts > 1); return operator_info(new operator_info::imp(num_parts, parts, fixity::Mixfixr, precedence));
}
operator_info mixfixc(unsigned num_parts, name const * parts, unsigned precedence) {
    lean_assert(num_parts > 1); return operator_info(new operator_info::imp(num_parts, parts, fixity::Mixfixc, precedence));
}

static char const * g_arrow               = "\u21a6";

format pp(operator_info const & o) {
    format r;
    switch (o.get_fixity()) {
    case fixity::Infixl:  r = format("Infixl"); break;
    case fixity::Infixr:  r = format("Infixr"); break;
    case fixity::Prefix:  r = format("Prefix");  break;
    case fixity::Postfix: r = format("Postfix"); break;
    case fixity::Mixfixl:
    case fixity::Mixfixr:
    case fixity::Mixfixc: r = format("Mixfix"); break;
    }

    r += space();

    if (o.get_precedence() != 0)
        r += format{format(o.get_precedence()), space()};

    switch (o.get_fixity()) {
    case fixity::Infixl: case fixity::Infixr: case fixity::Prefix: case fixity::Postfix:
        r += pp(o.get_op_name()); break;
    case fixity::Mixfixl:
        for (auto p : o.get_op_name_parts()) r += format{pp(p), format(" _")};
        break;
    case fixity::Mixfixr:
        for (auto p : o.get_op_name_parts()) r += format{format("_ "), pp(p)};
        break;
    case fixity::Mixfixc: {
        bool first = true;
        for (auto p : o.get_op_name_parts()) {
            if (first) first = false; else r += format(" _ ");
            r += pp(p);
        }
    }}

    list<name> const & l = o.get_internal_names();
    if (!is_nil(l)) {
        r += format{space(), format(g_arrow)};
        for (auto n : l) r += format{space(), pp(n)};
    }
    return r;
}

std::ostream & operator<<(std::ostream & out, operator_info const & o) {
    out << pp(o);
    return out;
}
}