/*-
 * Copyright (c) 2012-2013 Jan Breuer,
 *
 * All Rights Reserved
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @file   scpi_parser.c
 * @date   Thu Nov 15 10:58:45 UTC 2012
 * 
 * @brief  SCPI parser implementation
 * 
 * 
 */

#include <ctype.h>
#include <string.h>

#include "scpi/config.h"
#include "scpi/parser.h"
#include "scpi/lexer.h"
#include "utils.h"
#include "scpi/error.h"


static size_t cmdTerminatorPos(const char * cmd, size_t len);
static size_t cmdlineSeparatorPos(const char * cmd, size_t len);
static const char * cmdlineSeparator(const char * cmd, size_t len);
static const char * cmdlineTerminator(const char * cmd, size_t len);
static const char * cmdlineNext(const char * cmd, size_t len);

static void paramSkipBytes(scpi_t * context, size_t num);
static void paramSkipWhitespace(scpi_t * context);
static bool_t paramNext(scpi_t * context, bool_t mandatory);

/*
int _strnicmp(const char* s1, const char* s2, size_t len) {
    int result = 0;
    int i;

    for (i = 0; i < len && s1[i] && s2[i]; i++) {
        char c1 = tolower(s1[i]);
        char c2 = tolower(s2[i]);
        if (c1 != c2) {
            result = (int) c1 - (int) c2;
            break;
        }
    }

    return result;
}
 */

/**
 * Find command termination character
 * @param cmd - input command
 * @param len - max search length
 * @return position of terminator or len
 */
size_t cmdTerminatorPos(const char * cmd, size_t len) {
    const char * terminator = strnpbrk(cmd, len, "; \r\n\t");
    if (terminator == NULL) {
        return len;
    } else {
        return terminator - cmd;
    }
}

/**
 * Find command line separator
 * @param cmd - input command
 * @param len - max search length
 * @return pointer to line separator or NULL
 */
const char * cmdlineSeparator(const char * cmd, size_t len) {
    return strnpbrk(cmd, len, ";\r\n");
}

/**
 * Find command line terminator
 * @param cmd - input command
 * @param len - max search length
 * @return pointer to command line terminator or NULL
 */
const char * cmdlineTerminator(const char * cmd, size_t len) {
    return strnpbrk(cmd, len, "\r\n");
}

/**
 * Find command line separator position
 * @param cmd - input command
 * @param len - max search length
 * @return position of line separator or len
 */
size_t cmdlineSeparatorPos(const char * cmd, size_t len) {
    const char * separator = cmdlineSeparator(cmd, len);
    if (separator == NULL) {
        return len;
    } else {
        return separator - cmd;
    }
}

/**
 * Find next part of command
 * @param cmd - input command
 * @param len - max search length
 * @return Pointer to next part of command
 */
const char * cmdlineNext(const char * cmd, size_t len) {
    const char * separator = cmdlineSeparator(cmd, len);
    if (separator == NULL) {
        return cmd + len;
    } else {
        return separator + 1;
    }
}

/**
 * Write data to SCPI output
 * @param context
 * @param data
 * @param len - lenght of data to be written
 * @return number of bytes written
 */
static size_t writeData(scpi_t * context, const char * data, size_t len) {
    return context->interface->write(context, data, len);
}

/**
 * Flush data to SCPI output
 * @param context
 * @return
 */
static int flushData(scpi_t * context) {
    if (context && context->interface && context->interface->flush) {
        return context->interface->flush(context);
    } else {
        return SCPI_RES_OK;
    }
}

/**
 * Write result delimiter to output
 * @param context
 * @return number of bytes written
 */
static size_t writeDelimiter(scpi_t * context) {
    if (context->output_count > 0) {
        return writeData(context, ", ", 2);
    } else {
        return 0;
    }
}

/**
 * Conditionaly write "New Line"
 * @param context
 * @return number of characters written
 */
static size_t writeNewLine(scpi_t * context) {
    if (context->output_count > 0) {
        size_t len;
        len = writeData(context, "\r\n", 2);
        flushData(context);
        return len;
    } else {
        return 0;
    }
}

/**
 * Process command
 * @param context
 */
static void processCommand(scpi_t * context) {
    const scpi_command_t * cmd = context->paramlist.cmd;

    context->cmd_error = FALSE;
    context->output_count = 0;
    context->input_count = 0;

    SCPI_DEBUG_COMMAND(context);
    /* if callback exists - call command callback */
    if (cmd->callback != NULL) {
        if ((cmd->callback(context) != SCPI_RES_OK) && !context->cmd_error) {
            SCPI_ErrorPush(context, SCPI_ERROR_EXECUTION_ERROR);
        }
    }

    /* conditionaly write new line */
    writeNewLine(context);

    /* skip all whitespaces */
    paramSkipWhitespace(context);

    /* set error if command callback did not read all parameters */
    if (context->paramlist.length != 0 && !context->cmd_error) {
        SCPI_ErrorPush(context, SCPI_ERROR_PARAMETER_NOT_ALLOWED);
    }
}

/**
 * Cycle all patterns and search matching pattern. Execute command callback.
 * @param context
 * @result TRUE if context->paramlist is filled with correct values
 */
static bool_t findCommand(scpi_t * context, const char * cmdline_ptr, size_t cmdline_len, size_t cmd_len) {
    int32_t i;
    const scpi_command_t * cmd;

    for (i = 0; context->cmdlist[i].pattern != NULL; i++) {
        cmd = &context->cmdlist[i];
        if (matchCommand(cmd->pattern, cmdline_ptr, cmd_len)) {
            context->paramlist.cmd = cmd;
            context->paramlist.parameters = cmdline_ptr + cmd_len;
            context->paramlist.length = cmdline_len - cmd_len;
            return TRUE;
        }
    }
    return FALSE;
}

/**
 * Parse one command line
 * @param context
 * @param data - complete command line
 * @param len - command line length
 * @return 1 if the last evaluated command was found
 */
int SCPI_Parse(scpi_t * context, const char * data, size_t len) {
    int result = 0;
    const char * cmdline_end = data + len;
    const char * cmdline_ptr = data;
    size_t cmd_len;
    size_t cmdline_len;

    if (context == NULL) {
        return -1;
    }

    while (cmdline_ptr < cmdline_end) {
        result = 0;
        cmd_len = cmdTerminatorPos(cmdline_ptr, cmdline_end - cmdline_ptr);
        cmdline_len = cmdlineSeparatorPos(cmdline_ptr, cmdline_end - cmdline_ptr);
        if (cmd_len > 0) {
            if (findCommand(context, cmdline_ptr, cmdline_len, cmd_len)) {
                processCommand(context);
                result = 1;
            } else {
                SCPI_ErrorPush(context, SCPI_ERROR_UNDEFINED_HEADER);
            }
        }
        cmdline_ptr = cmdlineNext(cmdline_ptr, cmdline_end - cmdline_ptr);
    }
    return result;
}

/**
 * Initialize SCPI context structure
 * @param context
 * @param command_list
 * @param buffer
 * @param interface
 */
void SCPI_Init(scpi_t * context) {
    context->buffer.position = 0;
    SCPI_ErrorInit(context);
}

/**
 * Interface to the application. Adds data to system buffer and try to search
 * command line termination. If the termination is found or if len=0, command
 * parser is called.
 * 
 * @param context
 * @param data - data to process
 * @param len - length of data
 * @return 
 */
int SCPI_Input(scpi_t * context, const char * data, size_t len) {
    int result = 0;
    const char * cmd_term;
    if (len == 0) {
        context->buffer.data[context->buffer.position] = 0;
        result = SCPI_Parse(context, context->buffer.data, context->buffer.position);
        context->buffer.position = 0;
    } else {
        size_t buffer_free;
        int ws;
        buffer_free = context->buffer.length - context->buffer.position;
        if (len > (buffer_free - 1)) {
            return -1;
        }
        memcpy(&context->buffer.data[context->buffer.position], data, len);
        context->buffer.position += len;
        context->buffer.data[context->buffer.position] = 0;

        ws = skipWhitespace(context->buffer.data, context->buffer.position);
        cmd_term = cmdlineTerminator(context->buffer.data + ws, context->buffer.position - ws);
        if (cmd_term != NULL) {
            int curr_len = cmd_term - context->buffer.data;
            result = SCPI_Parse(context, context->buffer.data + ws, curr_len - ws);
            memmove(context->buffer.data, cmd_term, context->buffer.position - curr_len);
            context->buffer.position -= curr_len;
        }
    }

    return result;
}

/* writing results */

/**
 * Write raw string result to the output
 * @param context
 * @param data
 * @return 
 */
size_t SCPI_ResultString(scpi_t * context, const char * data) {
    size_t len = strlen(data);
    size_t result = 0;
    result += writeDelimiter(context);
    result += writeData(context, data, len);
    context->output_count++;
    return result;
}

/**
 * Write integer value to the result
 * @param context
 * @param val
 * @return 
 */
size_t SCPI_ResultInt(scpi_t * context, int32_t val) {
    char buffer[12];
    size_t result = 0;
    size_t len = longToStr(val, buffer, sizeof (buffer));
    result += writeDelimiter(context);
    result += writeData(context, buffer, len);
    context->output_count++;
    return result;
}

/**
 * Write double walue to the result
 * @param context
 * @param val
 * @return 
 */
size_t SCPI_ResultDouble(scpi_t * context, double val) {
    char buffer[32];
    size_t result = 0;
    size_t len = doubleToStr(val, buffer, sizeof (buffer));
    result += writeDelimiter(context);
    result += writeData(context, buffer, len);
    context->output_count++;
    return result;

}

/**
 * Write string withn " to the result
 * @param context
 * @param data
 * @return 
 */
size_t SCPI_ResultText(scpi_t * context, const char * data) {
    size_t result = 0;
    result += writeDelimiter(context);
    result += writeData(context, "\"", 1);
    result += writeData(context, data, strlen(data));
    result += writeData(context, "\"", 1);
    context->output_count++;
    return result;
}

/* parsing parameters */

/**
 * Skip num bytes from the begginig of parameters
 * @param context
 * @param num
 */
void paramSkipBytes(scpi_t * context, size_t num) {
    if (context->paramlist.length < num) {
        num = context->paramlist.length;
    }
    context->paramlist.parameters += num;
    context->paramlist.length -= num;
}

/**
 * Skip white spaces from the beggining of parameters
 * @param context
 */
void paramSkipWhitespace(scpi_t * context) {
    size_t ws = skipWhitespace(context->paramlist.parameters, context->paramlist.length);
    paramSkipBytes(context, ws);
}

/**
 * Find next parameter
 * @param context
 * @param mandatory
 * @return 
 */
bool_t paramNext(scpi_t * context, bool_t mandatory) {
    paramSkipWhitespace(context);
    if (context->paramlist.length == 0) {
        if (mandatory) {
            SCPI_ErrorPush(context, SCPI_ERROR_MISSING_PARAMETER);
        }
        return FALSE;
    }
    if (context->input_count != 0) {
        if (context->paramlist.parameters[0] == ',') {
            paramSkipBytes(context, 1);
            paramSkipWhitespace(context);
        } else {
            SCPI_ErrorPush(context, SCPI_ERROR_INVALID_SEPARATOR);
            return FALSE;
        }
    }
    context->input_count++;
    return TRUE;
}

/**
 * Parse integer parameter
 * @param context
 * @param value
 * @param mandatory
 * @return 
 */
bool_t SCPI_ParamInt(scpi_t * context, int32_t * value, bool_t mandatory) {
    const char * param;
    size_t param_len;
    size_t num_len;

    if (!value) {
        return FALSE;
    }

    if (!SCPI_ParamString(context, &param, &param_len, mandatory)) {
        return FALSE;
    }

    num_len = strToLong(param, value);

    if (num_len != param_len) {
        SCPI_ErrorPush(context, SCPI_ERROR_SUFFIX_NOT_ALLOWED);
        return FALSE;
    }

    return TRUE;
}

/**
 * Parse double parameter
 * @param context
 * @param value
 * @param mandatory
 * @return 
 */
bool_t SCPI_ParamDouble(scpi_t * context, double * value, bool_t mandatory) {
    const char * param;
    size_t param_len;
    size_t num_len;

    if (!value) {
        return FALSE;
    }

    if (!SCPI_ParamString(context, &param, &param_len, mandatory)) {
        return FALSE;
    }

    num_len = strToDouble(param, value);

    if (num_len != param_len) {
        SCPI_ErrorPush(context, SCPI_ERROR_SUFFIX_NOT_ALLOWED);
        return FALSE;
    }

    return TRUE;
}

/**
 * Parse string parameter
 * @param context
 * @param value
 * @param len
 * @param mandatory
 * @return 
 */
bool_t SCPI_ParamString(scpi_t * context, const char ** value, size_t * len, bool_t mandatory) {
    size_t length;

    if (!value || !len) {
        return FALSE;
    }

    if (!paramNext(context, mandatory)) {
        return FALSE;
    }

    if (locateStr(context->paramlist.parameters, context->paramlist.length, value, &length)) {
        paramSkipBytes(context, length);
        paramSkipWhitespace(context);
        if (len) {
            *len = length;
        }
        return TRUE;
    }

    return FALSE;
}

/**
 * Parse text parameter (can be inside "")
 * @param context
 * @param value
 * @param len
 * @param mandatory
 * @return 
 */
bool_t SCPI_ParamText(scpi_t * context, const char ** value, size_t * len, bool_t mandatory) {
    size_t length;

    if (!value || !len) {
        return FALSE;
    }

    if (!paramNext(context, mandatory)) {
        return FALSE;
    }

    if (locateText(context->paramlist.parameters, context->paramlist.length, value, &length)) {
        paramSkipBytes(context, length);
        if (len) {
            *len = length;
        }
        return TRUE;
    }

    return FALSE;
}

int SCPI_ParseProgramData(lex_state_t * state, token_t * token) {
    token_t tmp;
    int result = 0;
    int wsLen;
    int suffixLen;
    int realLen = 0;
    realLen += SCPI_LexWhiteSpace(state, &tmp);

    if (result == 0) result = SCPI_LexNondecimalNumericData(state, token);
    if (result == 0) result = SCPI_LexCharacterProgramData(state, token);
    if (result == 0) {
        result = SCPI_LexDecimalNumericProgramData(state, token);
        if (result != 0) {
            wsLen = SCPI_LexWhiteSpace(state, &tmp);
            suffixLen = SCPI_LexSuffixProgramData(state, &tmp);
            if (suffixLen > 0) {
                token->len += wsLen + suffixLen;
                token->type = TokDecimalNumericProgramDataWithSuffix;
                result = token->len;
            }
        }
    }

    if (result == 0) result = SCPI_LexStringProgramData(state, token);
    if (result == 0) result = SCPI_LexArbitraryBlockProgramData(state, token);
    if (result == 0) result = SCPI_LexProgramExpression(state, token);

    realLen += SCPI_LexWhiteSpace(state, &tmp);

    return result + realLen;
}

int SCPI_ParseAllProgramData(lex_state_t * state, token_t * token, int * numberOfParameters) {

    int result;
    token_t tmp;
    int paramCount = 0;

    token->len = -1;
    token->type = TokAllProgramData;
    token->ptr = state->pos;


    for (result = 1; result != 0; result = SCPI_LexComma(state, &tmp)) {
        token->len += result;

        if (result == 0) {
            token->type = TokUnknown;
            token->len = 0;
            break;
        }

        result = SCPI_ParseProgramData(state, &tmp);
        if (tmp.type != TokUnknown) {
            token->len += result;
        } else {
            token->type = TokUnknown;
            token->len = 0;
            break;
        }
        paramCount++;
    }

    if (token->len == -1) {
        token->len = 0;
    }

    if (numberOfParameters != NULL) {
        *numberOfParameters = paramCount;
    }
    return token->len;
}

int SCPI_DetectProgramMessageUnit(scpi_t * context) {
    lex_state_t state;
    token_t tmp;
    int result = 0;

    state.buffer = state.pos = context->buffer.data;
    state.len = context->buffer.position;

    /* ignore whitespace at the begginig */
    SCPI_LexWhiteSpace(&state, &tmp);

    SCPI_LexProgramHeader(&state, &context->parser_state.programHeader);

    SCPI_LexWhiteSpace(&state, &tmp);

    SCPI_ParseAllProgramData(&state, &context->parser_state.programData, &context->parser_state.numberOfParameters);

    if (result == 0) result = SCPI_LexNewLine(&state, &tmp);
    if (result == 0) result = SCPI_LexSemicolon(&state, &tmp);

    if (TokSemicolon == tmp.type) {
        context->parser_state.termination = PmutSemicolon;
    } else if (TokNewLine == tmp.type) {
        context->parser_state.termination = PmutNewLine;
    } else {
        context->parser_state.termination = PmutNone;
    }
}