/* Software License Agreement
 * 
 *     Copyright(C) 1994-2021 David Lindauer, (LADSoft)
 * 
 *     This file is part of the Orange C Compiler package.
 * 
 *     The Orange C Compiler package is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 * 
 *     The Orange C Compiler package is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 * 
 *     You should have received a copy of the GNU General Public License
 *     along with Orange C.  If not, see <http://www.gnu.org/licenses/>.
 * 
 *     contact information:
 *         email: TouchStone222@runbox.com <David Lindauer>
 * 
 */

#include "PreProcessor.h"
#include "ppMacro.h"
#include "ppkw.h"
#include "UTF8.h"
#include <fstream>
#include <climits>

ppMacro::ppMacro(ppInclude& Include, ppDefine& Define) : include(Include), expr(false), define(Define), nextMacro(1), pp(nullptr)
{
    expr.SetParams(&define);
}
ppMacro::~ppMacro() {}
bool ppMacro::Check(kw token, std::string& line)
{
    bool rv = false;
    switch (token)
    {
        case kw::REP:
            rv = HandleRep(line);
            break;
        case kw::EXITREP:
            include.Release();
            rv = HandleExitRep();
            break;
        case kw::ENDREP:
            rv = HandleEndRep();
            break;
        case kw::MACRO:
            rv = HandleMacro(line, false);
            break;
        case kw::IMACRO:
            rv = HandleMacro(line, true);
            break;
        case kw::ENDMACRO:
            rv = HandleEndMacro();
            break;
        case kw::ROTATE:
            rv = HandleRotate(line);
            break;
    }
    return rv;
}
bool ppMacro::GetLine(std::string& line, int& lineno)
{
    while (!stack.empty())
    {
        MacroData* p = stack.back().get();
        if (p->offset >= p->lines.size())
        {
            p->offset = 0;
            if (--p->repsLeft == 0)
            {
                include.Drop();
                HandleExitRep();
                continue;
            }
        }
        else
        {
            if (!p->isNative)
                lineno = p->offset + p->begline;
            line = p->lines[p->offset++];
            return true;
        }
    }
    return false;
}
bool ppMacro::HandleRep(std::string& line)
{
    define.Process(line);
    PPINT n = expr.Eval(line);
    int level = 1;
    std::unique_ptr<MacroData> p;
    if (n < 0 || n > INT_MAX)
    {
        Errors::Error("Invalid range in %rep expression");
    }
    else if (n > 0)
    {
        p = std::make_unique<MacroData>();
        p->repsLeft = (int)n;
        p->offset = 0;
        p->id = -1;
        p->begline = 0;
        p->isNative = false;
        p->caseInsensitive = false;
    }
    std::string ll;
    include.SetInProc("%rep");
    while (pp->GetPreLine(ll))
    {
        if (p->begline == 0)
            p->begline = pp->GetMainLineNo();
        std::string orig = ll;
        int t = ll.find_first_not_of(" \t\v\r\n");
        if (t != std::string::npos)
        {
            define.Process(ll);
            t = ll.find_first_not_of(" \t\v\r\n");
            if (t != std::string::npos && ll[t] == '%')
            {
                t = ll.find_first_not_of(" \t\v\r\n", t + 1);
                if (ll.substr(t, 5) == "macro")
                    Errors::Error("macro definition in %rep loop not allowed");
                else if (ll.substr(t, 3) == "rep")
                    level++;
                else if (ll.substr(t, 6) == "endrep")
                    if (!--level)
                        break;
            }
            if (p)
                p->lines.push_back(ll);
        }
    }
    include.SetInProc("");
    if (level == 0 && p)
    {
        include.Mark();
        stack.push_back(std::move(p));
    }
    return true;
}
bool ppMacro::HandleExitRep()
{
    MacroData* p = stack.back().release();
    stack.pop_back();
    if (p->id < 0)
        delete p;
    return true;
}
bool ppMacro::HandleEndRep()
{
    Errors::Error("unexpected %endrep");
    return true;
}
std::string ppMacro::ExtractArg(std::string& line)
{
    int npos;
    if (line[0] == '{')
    {
        npos = line.find_first_of('}');
    }
    else
    {
        npos = line.find_first_of(',');
    }
    if (npos == -1)
        npos = line.size();
    std::string rv = line.substr(0, npos);
    line.erase(0, npos + 1);
    if (rv[0] == '{')
    {
        rv.erase(0, 1);
        npos = line.find_first_not_of(" \t\r\v\n");
        if (npos != std::string::npos)
            if (line[npos] != ',')
                Errors::Error("Expected ','");
            else
                line.erase(0, npos + 1);
        else
            line = "";
    }
    else
    {
        npos = rv.find_last_not_of(" \t\r\n\v");
        if (npos == std::string::npos)
            rv = "";
        else if (npos != rv.size() - 1)
            rv.erase(npos + 1, rv.size() - npos - 1);
    }
    return rv;
}
void ppMacro::GetArgs(int max, std::string& line, std::vector<std::string>& vals)
{
    for (int i = 0; i < max; i++)
    {
        int npos = line.find_first_not_of(" \t\r\n\v");
        if (npos == std::string::npos)
        {
            line = "";
            break;
        }
        line.erase(0, npos);
        std::string temp = ExtractArg(line);
        vals.push_back(temp);
    }
    int npos = line.find_first_not_of(" \t\r\n\v");
    if (npos != std::string::npos)
    {
        line.erase(0, npos);
        npos = line.find_last_not_of(" \t\r\n\v");
        if (npos != std::string::npos && npos < line.size() - 1)
            line.erase(npos + 1, line.size() - npos - 1);
    }
}
bool ppMacro::HandleMacro(std::string& line, bool caseInsensitive)
{
    bool nolist = false;
    bool native = false;
    define.Process(line);
    std::string name;
    int start, end;
    bool plussign;
    Tokenizer tk(line, ppExpr::GetHash());
    const Token* next = tk.Next();
    MacroData* p = nullptr;
    bool bailed = false;
    if (next->IsIdentifier())
    {
        name = next->GetId();
        if (caseInsensitive)
            name = UTF8::ToUpper(name);
        next = tk.Next();
        if (next->IsNumeric())
        {
            start = end = next->GetInteger();
            plussign = false;
            next = tk.Next();
            if (next->GetKeyword() == kw::minus)
            {
                next = tk.Next();
                if (next->IsNumeric())
                {
                    end = next->GetInteger();
                    if (end < start)
                    {
                        Errors::Error("Macro end limit < start limit");
                        bailed = true;
                    }
                    else
                    {
                        next = tk.Next();
                        if (next->GetKeyword() == kw::plus)
                        {
                            next = tk.Next();
                            plussign = true;
                        }
                    }
                }
                else if (next->GetKeyword() == kw::star)
                {
                    end = INT_MAX;
                }
                else
                {
                    Errors::Error("Macro argument end limit expected");
                    bailed = true;
                }
            }
            else if (next->GetKeyword() == kw::plus)
            {
                next = tk.Next();
                plussign = true;
            }
            if (next->IsIdentifier())
            {
                if (next->GetId() == ".nolist")
                {
                    next = tk.Next();
                    nolist = true;
                }
                else if (next->GetId() == ".native")
                {
                    next = tk.Next();
                    native = true;
                }
            }
        }
        else
        {
            Errors::Error("Macro argument count expected");
            bailed = true;
        }
    }
    else
    {
        Errors::Error("Macro name expected");
        bailed = true;
    }
    if (!bailed)
    {
        p = new MacroData;
        p->repsLeft = 0;
        p->offset = 0;
        p->id = 0;  // macro
        p->argmin = start;
        p->argmax = end;
        p->plus = plussign;
        p->begline = 0;
        p->isNative = native;
        p->caseInsensitive = caseInsensitive;
        line = next->GetChars() + tk.GetString();
        int count = 0;
        GetArgs(end - start, line, p->defaults);
        if (!line.empty())
        {
            if (line.find_first_not_of(" \t\r\n\v") == std::string::npos)
                line.erase(0, line.size());
        }
        if ((p->defaults.size() + (line.size() != 0)) > end - start + plussign)
            Errors::Error("Too many default arguments to macro");
        if (!line.empty())
            p->defaults.push_back(line);
    }
    std::string ll;
    include.SetInProc("%macro");
    while (pp->GetPreLine(ll))
    {
        if (p && p->begline == 0)
            p->begline = nolist ? INT_MIN : pp->GetMainLineNo();
        int t = ll.find_first_not_of(" \t\v\r\n");
        if (t != std::string::npos)
        {
            if (ll[t] == '%')
            {
                t = ll.find_first_not_of(" \t\v\r\n", t + 1);
                if (ll.substr(t, 5) == "macro")
                    Errors::Error("macro definitions may not be nested");
                else if (ll.substr(t, 8) == "endmacro")
                    break;
            }
            if (p)
                p->lines.push_back(ll);
        }
    }
    include.SetInProc("");
    if (p)
        macros[name] = p;
    return true;
}
bool ppMacro::HandleEndMacro()
{
    Errors::Error("unexpected %endmacro");
    return true;
}
void ppMacro::reverse(std::vector<std::string>& x, int offs, int len)
{
    for (int i = 0; i < len / 2; i++)
    {
        std::swap(x[offs + i], x[offs + len - i - 1]);
    }
}
bool ppMacro::HandleRotate(std::string& line)
{
    MacroData* p = GetTopMacro();
    if (!p)
    {
        Errors::Error("%rotate outside of macro invocation");
    }
    else
    {
        define.Process(line);
        PPINT m = expr.Eval(line);
        if (m < INT_MIN || m > INT_MAX)
        {
            Errors::Error("Invalid rotation count");
        }
        int n = (int)m;
        if (n < 0)
        {
            n = -n;
            n %= p->args.size();
            n = p->args.size() - n;
        }
        else
        {
            n %= p->args.size();
        }
        if (n != 0)
        {
            reverse(p->args, 0, n);
            reverse(p->args, n, p->args.size() - n);
            reverse(p->args, 0, p->args.size());
        }
    }
    return true;
}
bool ppMacro::Invoke(std::string name, std::string line)
{
    auto it = macros.find(name);
    if (it == macros.end())
    {
        std::string name1 = UTF8::ToUpper(name);
        it = macros.find(name1);
        if (it == macros.end() || it->second->caseInsensitive == false)
            return false;
        else
            name = name1;
    }
    MacroData* p = it->second;
    if (p->repsLeft != 0)
    {
        return false;
    }
    p->args.clear();
    GetArgs(p->argmax, line, p->args);
    if (!line.empty())
    {
        if (line.find_first_not_of(" \t\r\n\v") == std::string::npos)
            line.erase(0, line.size());
    }
    if (p->args.size() < p->argmin)
    {
        Errors::Error("Too few arguments in call to macro");
        return true;
    }
    else if ((p->args.size() + (line.size() != 0)) > (p->argmax + p->plus))
    {
        Errors::Error("Too many arguments in call to macro");
        return true;
    }
    while (p->defaults.size() + p->argmin > p->args.size())
    {
        p->args.push_back(p->defaults[p->args.size() - p->argmin]);
    }
    if (!line.empty())
        p->args.push_back(line);
    p->id = nextMacro++;
    p->repsLeft = 1;
    include.Mark();
    std::unique_ptr<MacroData> temp(p);
    stack.push_back(std::move(temp));
    return true;
}
MacroData* ppMacro::GetTopMacro()
{
    for (int i = stack.size() - 1; i >= 0; i--)
        if (stack[i]->id != -1)
            return stack[i].get();
    return nullptr;
}
