#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "vcd_parser.h"

#ifndef VCDWASM
#include <node_api.h>
#else
#include "wasm_main.hpp"
#endif

#ifdef VCDWASM
typedef void* napi_env;
#endif

// #define LOGSPAN
// #define LOGSPAN printf("%s\n", __FUNCTION__);

#define ASSERT(val, expr)     \
    if (expr != napi_ok) {    \
        napi_throw(env, val); \
    }

void strcopy(const unsigned char* p, const unsigned char* endp,
             unsigned char* dst) {
    const unsigned char* src;
    src = p;
    while (src < (endp - 1)) {
        *dst = *src;
        src++;
        dst++;
    }
    *dst = 0;
}

void strconcat(const unsigned char* p, const unsigned char* endp,
               unsigned char* dst) {
    // printf("<len:%d>", endp - p);
    dst += strlen((char*)dst);  // go to the end of string
    while (p < endp) {
        *dst = *p;
        p++;
        dst++;
    }
    *dst = 0;
}

// FIXME use a better structure to match strings
int stringEq(const unsigned char* i,  // search pattern
             const unsigned char* p, const unsigned char* endp) {
    if (*i == 0) {
        return 1;
    }
    const unsigned char* j;
    while (1) {
        j = p;
        // printf("(%s|%s)", (char *)i, (char *)j);
        if (*i == 0) {  // end of search pattern
            return 0;
        }
        while (*i == *j) {             // follow matching trail
            if (*i == 0 && *j == 0) {  // match zeros
                return 1;
            }
            i++;
            j++;
        }
        while (*i != 0) {  // skip to the end of pattern word
            i++;
        }
        i++;
    }
}

int commandSpan(vcd_parser_t* state, const unsigned char* p,
                const unsigned char* endp) {
    const uint8_t command = state->command;
#ifndef VCDWASM
    napi_env env = state->napi_env;

    // if (command == 5) { // $upscope
    //   state->stackPointer -= 1;
    //   return 0;
    // }

    if ((command == 1) ||  // $comment
        (command == 2) ||  // $date
        (command == 3) ||  // $scope
        (command == 4) ||  // $timescale
        (command == 5) ||  // $upscope
        (command == 6) ||  // $var
        (command == 7)     // $version
    ) {
        char* key;
        switch (command) {
            case 1:
                key = "comment";
                break;
            case 2:
                key = "date";
                break;
            case 4:
                key = "timescale";
                break;
            // case 6: key = "var"; break;
            case 7:
                key = "version";
                break;
        }

        napi_value val;
        ASSERT(val,
               napi_create_string_latin1(env, (char*)p, (endp - p - 4), &val))
        ASSERT(state->info, napi_set_named_property(env, state->info, key, val))
        return 0;
    }
#else
    if ((command > 0) && (command < 8)) {
        const int len = endp - p;
        int tailLen = 3;
        if (len < 4) {
            tailLen = len;
        }
        strcopy(p, endp - tailLen, state->tmpStr);
        // set_property_string(key, state->tmpStr);
        on_command(state->tmpStr, command);
        return 0;
    }
#endif

    if (command == 8) {  // $enddefinitions
        *(char*)state->idStr = 0;
        *(char*)state->timeStampStr = 0;
#ifndef VCDWASM
        napi_value status, undefined, eventName, eventPayload, return_val;
        ASSERT(status, napi_create_string_latin1(env, "simulation",
                                                 NAPI_AUTO_LENGTH, &status))
        ASSERT(state->info,
               napi_set_named_property(env, state->info, "status", status))
        ASSERT(undefined, napi_get_undefined(env, &undefined))
        ASSERT(eventName,
               napi_create_string_latin1(env, "$enddefinitions",
                                         NAPI_AUTO_LENGTH, &eventName))
        // ASSERT(eventPayload, napi_create_string_latin1(env, "payload",
        // NAPI_AUTO_LENGTH, &eventPayload))
        napi_value* argv[] = {&eventName};  // , &eventPayload };
        ASSERT(state->lifee, napi_call_function(env, undefined, state->lifee, 1,
                                                *argv, &return_val))
#else
        set_property_string("status", "simulation");
        emit_lifee("$enddefinitions");
#endif
        return 0;
    }

    return 0;
}

int scopeIdentifierSpan(vcd_parser_t* state, const unsigned char* p,
                        const unsigned char* endp) {
    strcopy(p, endp, state->tmpStr);  // load the value into temp string 1
#ifndef VCDWASM
    napi_env env = state->napi_env;
    napi_value obj, stack, top;
    ASSERT(obj, napi_create_object(env, &obj))
    ASSERT(state->info,
           napi_get_named_property(env, state->info, "stack", &stack))

    // get the top of the stack in top
    ASSERT(top, napi_get_element(env, stack, state->stackPointer, &top))

    // set top.prop to new object
    ASSERT(top, napi_set_named_property(env, top, state->tmpStr, obj))

    state->stackPointer += 1;
    ASSERT(top, napi_set_element(env, stack, state->stackPointer, obj))
#else
    // set stack[sp].`tmpStr` to {}
    snprintf(state->tmpStr2, 4096, "stack.%d.%s", state->stackPointer,
             (char*)state->tmpStr);
    new_object_path(state->tmpStr2);

    // bump
    state->stackPointer += 1;

    // set stack[sp+1] to the same object as stack[sp].`tmpStr`
    snprintf(state->tmpStr, 4096, "stack.%d", state->stackPointer);

    set_path_to_path(state->tmpStr, state->tmpStr2);
#endif
    return 0;
}

int varSizeSpan(vcd_parser_t* state, const unsigned char* p,
                const unsigned char* endp) {
    const int32_t size = strtol((const char*)p, (char**)&endp, 10);
    state->size = size;
#ifndef VCDWASM
#else
    set_property_int("varType", state->type);
    set_property_int("varSize", size);
#endif
    return 0;
}

int varIdSpan(vcd_parser_t* state, const unsigned char* p,
              const unsigned char* endp) {
#ifndef VCDWASM
    napi_env env = state->napi_env;
    napi_value varId;
    ASSERT(varId,
           napi_create_string_latin1(env, (char*)p, (endp - p - 1), &varId))
    ASSERT(state->info,
           napi_set_named_property(env, state->info, "varId", varId))
#else
    strcopy(p, endp, state->tmpStr);
    set_property_string("varId", state->tmpStr);
#endif
    return 0;
}

int varNameSpan(vcd_parser_t* state, const unsigned char* p,
                const unsigned char* endp) {
#ifndef VCDWASM
    napi_env env = state->napi_env;
    // *(endp - 1) = 0; // FIXME NULL termination of ASCII string
    strcopy(p, endp, state->tmpStr);
    napi_value stack, top, varId;
    ASSERT(state->info,
           napi_get_named_property(env, state->info, "stack", &stack))
    ASSERT(top, napi_get_element(env, stack, state->stackPointer, &top))
    ASSERT(state->info,
           napi_get_named_property(env, state->info, "varId", &varId))
    ASSERT(state->info, napi_set_named_property(env, top, state->tmpStr, varId))
#else
    strcopy(p, endp, state->tmpStr);
    // set
    //  info.stack[sp].`tmpStr` = info.varId
    snprintf(state->tmpStr2, 4096, "stack.%d.%s", state->stackPointer,
             (char*)state->tmpStr);
    set_path_to_path(state->tmpStr2, "varType,varSize,varId");
#endif
    return 0;
}

int idSpan(vcd_parser_t* state, const unsigned char* p,
           const unsigned char* endp) {
    strconcat(p, endp, state->idStr);
    // printf("<idSpan|%s>\n", (char *)state->idStr);
    return 0;
}

int onId(vcd_parser_t* state, const unsigned char* _p,
         const unsigned char* _endp) {
#ifndef VCDWASM
    napi_env env = state->napi_env;
#endif
    const unsigned char* p = (unsigned char*)state->idStr;
    const unsigned int plen = strlen((char*)p) - 1;
    *(char*)(p + plen) = 0;  // null instead of space
    const unsigned char* endp = p + plen - 1;
    // printf("<onId|%s>\n", (char *)state->idStr);

    const int valueWords = (state->digitCount + 63) >> 6;
    const int maskWords = (state->maskCount + 63) >> 6;
    uint64_t* value = state->value;
    uint64_t* mask = state->mask;
    if (stringEq((state->trigger), p, endp)) {
        const uint8_t command = state->command;
        // printf("{id:'%s',cmd:%d}", (char *)p, command);
        // if (command == 14) {
        //   value[0] = 0;
        //   mask[0] = 0;
        // } else
        // if (command == 15) {
        //   value[0] = 1;
        //   mask[0] = 0;
        // }
#ifndef VCDWASM
        napi_value undefined, eventName, aTime, aCommand, aValue, aMask,
            return_val;
        ASSERT(undefined, napi_get_undefined(env, &undefined))
        ASSERT(eventName, napi_create_string_latin1(
                              env, (char*)p, NAPI_AUTO_LENGTH, &eventName))
        ASSERT(aTime, napi_create_int64(env, state->time, &aTime))
        ASSERT(aCommand, napi_create_int32(env, command, &aCommand))
        ASSERT(aValue,
               napi_create_bigint_words(env, 0, valueWords, value, &aValue))
        ASSERT(aMask, napi_create_bigint_words(env, 0, maskWords, mask, &aMask))
        napi_value* argv[] = {&eventName, &aTime, &aCommand, &aValue, &aMask};
        ASSERT(state->triee, napi_call_function(env, undefined, state->triee, 5,
                                                *argv, &return_val))
        // printf("<id='%s'>", (char *)p);
#else
        // strcopy(p, endp, state->tmpStr);
        emit_triee((char*)p, state->time, command, valueWords, value, maskWords,
                   mask);
#endif
    }
    for (int i = 0; i < valueWords; i++) {
        value[i] = 0;
    }
    for (int i = 0; i < maskWords; i++) {
        mask[i] = 0;
    }
    state->digitCount = 0;
    state->maskCount = 0;
    *(char*)state->idStr = 0;
    return 0;
}

// 匹配 value id 这样的格式
int onDigit(vcd_parser_t* state, const unsigned char* _p,
            const unsigned char* _endp, int digit) {
    unsigned int valueCin = (digit & 1);
    unsigned int maskCin = ((digit >> 1) & 1);

    if ((valueCin != 0) || (state->digitCount != 0)) {
        unsigned int valueCout;
        uint64_t* value = state->value;
        const int valueWordsMinus = (state->digitCount >> 6);
        for (int i = 0; i <= valueWordsMinus; i++) {
            valueCout = value[i] >> 63;
            value[i] = (value[i] << 1) + valueCin;
            valueCin = valueCout;
        }
        state->digitCount += 1;
    }
    if ((maskCin != 0) || (state->maskCount != 0)) {
        unsigned int maskCout;
        uint64_t* mask = state->mask;
        const int maskWordsMinus = (state->maskCount >> 6);
        for (int i = 0; i <= maskWordsMinus; i++) {
            maskCout = mask[i] >> 63;
            mask[i] = (mask[i] << 1) + maskCin;
            maskCin = maskCout;
        }
        state->maskCount += 1;
    }
    return 0;
}

int onRecover(vcd_parser_t* state, const unsigned char* p,
              const unsigned char* endp, int digit) {
    state->digitCount = 0;
    state->maskCount = 0;
    return 0;
}

int timeSpan(vcd_parser_t* state, const unsigned char* p,
             const unsigned char* endp) {
    strconcat(p, endp, state->timeStampStr);
    // printf("<timeSpan|%s>\n", (char *)state->timeStampStr);
    return 0;
}

int onTime(vcd_parser_t* state, const unsigned char* _p,
           const unsigned char* _endp) {
    char* end;
    const int64_t time = strtoul(state->timeStampStr, &end, 10);
    // printf("<onTime|%lu>\n", time);
    if (state->time == INT64_MAX) {
#ifndef VCDWASM
        napi_env env = state->napi_env;
        napi_value val;
        ASSERT(val, napi_create_int64(env, time, &val))
        ASSERT(state->info,
               napi_set_named_property(env, state->info, "t0", val))
#else
        set_property_int("t0", time);
#endif
    }
    state->time = time;
    *(char*)state->timeStampStr = 0;
    return 0;
}