/**************************************************************************
 *
 * Copyright 2010 VMware, Inc.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 **************************************************************************/

#ifndef _TRACE_PARSER_HPP_
#define _TRACE_PARSER_HPP_


#include <cassert>

#include <iostream>
#include <map>
#include <list>
#include <string>

#include <zlib.h>

#include "trace_format.hpp"
#include "trace_model.hpp"


#define TRACE_VERBOSE 0


namespace Trace {


class Parser
{
protected:
    gzFile file;

    typedef std::list<Call *> CallList;
    CallList calls;

    typedef std::vector<Call::Signature *> FunctionMap;
    FunctionMap functions;

    typedef std::vector<Struct::Signature *> StructMap;
    StructMap structs;

    typedef std::vector<Enum *> EnumMap;
    EnumMap enums;

    typedef std::vector<Bitmask::Signature *> BitmaskMap;
    BitmaskMap bitmasks;

    unsigned next_call_no;

public:
    Parser() {
        file = NULL;
        next_call_no = 0;
    }

    ~Parser() {
        close();
    }

    bool open(const char *filename) {
        unsigned long long version;

        file = gzopen(filename, "rb");
        if (!file) {
            return false;
        }

        version = read_uint();
        if (version != TRACE_VERSION) {
            std::cerr << "error: unsupported format version" << version << "\n";
            return false;
        }

        return true;
    }

    void close(void) {
        if (file) {
            gzclose(file);
            file = NULL;
        }
    }

    Call *parse_call(void) {
        do {
            int c = read_byte();
            switch(c) {
            case Trace::EVENT_ENTER:
                parse_enter();
                break;
            case Trace::EVENT_LEAVE:
                return parse_leave();
            case Trace::EVENT_MESSAGE:
                std::cerr << "message: " << read_string() << "\n";
                break;
            default:
                std::cerr << "error: unknown call detail " << c << "\n";
                assert(0);
                /* fallthrough */
            case -1:
                return NULL;
            }
        } while(true);
    }

    /**
     * Helper function to lookup an ID in a vector, resizing the vector if it doesn't fit.
     */
    template<class T>
    T *lookup(std::vector<T *> &map, size_t index) {
        if (index >= map.size()) {
            map.resize(index + 1);
            return NULL;
        } else {
            return map[index];
        }
    }

    void parse_enter(void) {
        size_t id = read_uint();

        Call::Signature *sig = lookup(functions, id);
        if (!sig) {
            sig = new Call::Signature;
            sig->name = read_string();
            unsigned size = read_uint();
            for (unsigned i = 0; i < size; ++i) {
                sig->arg_names.push_back(read_string());
            }
            functions[id] = sig;
        }
        assert(sig);

        Call *call = new Call(sig);
        call->no = next_call_no++;

        parse_call_details(call);

        calls.push_back(call);
    }

    Call *parse_leave(void) {
        unsigned call_no = read_uint();

        Call *call = NULL;
        for (CallList::iterator it = calls.begin(); it != calls.end(); ++it) {
            if ((*it)->no == call_no) {
                call = *it;
                calls.erase(it);
                break;
            }
        }
        assert(call);
        if (!call) {
            return NULL;
        }
        parse_call_details(call);
        return call;
    }

    void parse_call_details(Call *call) {
        do {
            int c = read_byte();
            switch(c) {
            case Trace::CALL_END:
                return;
            case Trace::CALL_ARG:
                parse_arg(call);
                break;
            case Trace::CALL_RET:
                call->ret = parse_value();
                break;
            default:
                std::cerr << "error: unknown call detail " << c << "\n";
                assert(0);
                /* fallthrough */
            case -1:
                return;
            }
        } while(true);
    }

    void parse_arg(Call *call) {
        unsigned index = read_uint();
        Value *value = parse_value();
        if (index >= call->args.size()) {
            call->args.resize(index + 1);
        }
        call->args[index] = value;
    }

    Value *parse_value(void) {
        int c;
        c = read_byte();
        switch(c) {
        case Trace::TYPE_NULL:
            return new Null;
        case Trace::TYPE_FALSE:
            return new Bool(false);
        case Trace::TYPE_TRUE:
            return new Bool(true);
        case Trace::TYPE_SINT:
            return parse_sint();
        case Trace::TYPE_UINT:
            return parse_uint();
        case Trace::TYPE_FLOAT:
            return parse_float();
        case Trace::TYPE_DOUBLE:
            return parse_double();
        case Trace::TYPE_STRING:
            return parse_string();
        case Trace::TYPE_ENUM:
            return parse_enum();
        case Trace::TYPE_BITMASK:
            return parse_bitmask();
        case Trace::TYPE_ARRAY:
            return parse_array();
        case Trace::TYPE_STRUCT:
            return parse_struct();
        case Trace::TYPE_BLOB:
            return parse_blob();
        case Trace::TYPE_OPAQUE:
            return parse_opaque();
        default:
            std::cerr << "error: unknown type " << c << "\n";
            assert(0);
            return NULL;
        }
    }

    Value *parse_sint() {
        return new SInt(-(signed long long)read_uint());
    }

    Value *parse_uint() {
        return new UInt(read_uint());
    }

    Value *parse_float() {
        float value;
        gzread(file, &value, sizeof value);
        return new Float(value);
    }

    Value *parse_double() {
        double value;
        gzread(file, &value, sizeof value);
        return new Float(value);
    }

    Value *parse_string() {
        return new String(read_string());
    }

    Value *parse_enum() {
        size_t id = read_uint();
        Enum *sig = lookup(enums, id);
        if (!sig) {
            std::string name = read_string();
            Value *value = parse_value();
            sig = new Enum(name, value);
            enums[id] = sig;
        }
        assert(sig);
        return sig;
    }

    Value *parse_bitmask() {
        size_t id = read_uint();
        Bitmask::Signature *sig = lookup(bitmasks, id);
        if (!sig) {
            size_t size = read_uint();
            sig = new Bitmask::Signature(size);
            for (Bitmask::Signature::iterator it = sig->begin(); it != sig->end(); ++it) {
                it->first = read_string();
                it->second = read_uint();
                assert(it->second);
            }
            bitmasks[id] = sig;
        }
        assert(sig);

        unsigned long long value = read_uint();

        return new Bitmask(sig, value);
    }

    Value *parse_array(void) {
        size_t len = read_uint();
        Array *array = new Array(len);
        for (size_t i = 0; i < len; ++i) {
            array->values[i] = parse_value();
        }
        return array;
    }

    Value *parse_blob(void) {
        size_t size = read_uint();
        Blob *blob = new Blob(size);
        if (size) {
            gzread(file, blob->buf, size);
        }
        return blob;
    }

    Value *parse_struct() {
        size_t id = read_uint();

        Struct::Signature *sig = lookup(structs, id);
        if (!sig) {
            sig = new Struct::Signature;
            sig->name = read_string();
            unsigned size = read_uint();
            for (unsigned i = 0; i < size; ++i) {
                sig->member_names.push_back(read_string());
            }
            structs[id] = sig;
        }
        assert(sig);

        Struct *value = new Struct(sig);

        for (size_t i = 0; i < sig->member_names.size(); ++i) {
            value->members[i] = parse_value();
        }

        return value;
    }

    Value *parse_opaque() {
        unsigned long long addr;
        addr = read_uint();
        /* XXX */
        return new UInt(addr);
    }

    std::string read_string(void) {
        size_t len = read_uint();
        if (!len) {
            return std::string();
        }
        char * buf = new char[len];
        gzread(file, buf, len);
        std::string value(buf, len);
        delete [] buf;
#if TRACE_VERBOSE
        std::cerr << "\tSTRING \"" << value << "\"\n";
#endif
        return value;
    }

    unsigned long long read_uint(void) {
        unsigned long long value = 0;
        int c;
        unsigned shift = 0;
        do {
            c = gzgetc(file);
            if (c == -1) {
                break;
            }
            value |= (unsigned long long)(c & 0x7f) << shift;
            shift += 7;
        } while(c & 0x80);
#if TRACE_VERBOSE
        std::cerr << "\tUINT " << value << "\n";
#endif
        return value;
    }

    int read_byte(void) {
        int c = gzgetc(file);
#if TRACE_VERBOSE
        if (c < 0)
            std::cerr << "\tEOF" << "\n";
        else
            std::cerr << "\tBYTE 0x" << std::hex << c << std::dec << "\n";
#endif
        return c;
    }
};


} /* namespace Trace */

#endif /* _TRACE_PARSER_HPP_ */