#include "DTE.h"

DTE::DTE(Stream & stream, unsigned int size)
    : stream(stream), bufferSize(size), result(EXPECT_RESULT)
{
    buffer.reserve(size);
}

void DTE::SendCommand(const char * command, unsigned long timeout, const char * response1, const char * response2, const char * response3)
{
    match = 0;
    result = EXPECT_BUSY;
    response[0] = response1;
    response[1] = response2;
    response[2] = response3;
    this->timeout = timeout;
    flush();
    stream.print(command);
    buffer = "";
    tick = millis();
    process();
}

void DTE::SendCommand(const __FlashStringHelper * command, unsigned long timeout, const char * response1, const char * response2, const char * response3)
{

    match = 0;
    result = EXPECT_BUSY;
    response[0] = response1;
    response[1] = response2;
    response[2] = response3;
    this->timeout = timeout;
    // clear rx buffer
    flush();
    // send command
    stream.print((const __FlashStringHelper *) command);
    buffer = "";
    tick = millis();
    process();
}

void DTE::Delay(unsigned long delay)
{
    timeout = delay;
    result = EXPECT_DELAY;
    tick = millis();
    process();
}

bool DTE::getIsBusy()
{
    process();
    return (result == EXPECT_BUSY) || (result == EXPECT_DELAY);
}

DTE::CommandResult DTE::getResult()
{
    return result;
}

unsigned int DTE::getMatch() const
{
    return match;
}

String & DTE::getBuffer()
{
    return buffer;
}

void DTE::flush()
{
    // clear rx buffer
    while (stream.available()) {
        stream.read();
    }
}

void DTE::process()
{
    if (result == EXPECT_DELAY) {
        if (millis() - tick >= timeout)
            result = EXPECT_RESULT;

        return;
    }

    if (result != EXPECT_BUSY)
        return;

    char c;
    unsigned long now = millis();

    while (millis() - tick < timeout) {
        while (stream.available() && (buffer.length() < bufferSize)) {
            c = stream.read();
            buffer.concat(c);
            if (buffer.endsWith(response[0])) {
                match = 0;
                result = EXPECT_RESULT;
                return;
            } else if (response[1].length() != 0) {
                if (buffer.endsWith(response[1])) {
                    match = 1;
                    result = EXPECT_RESULT;
                    return;
                }
            } else if (response[2].length() != 0) {
                if (buffer.endsWith(response[2])) {
                    match = 2;
                    result = EXPECT_RESULT;
                    return;
                }
            }
        }
        if (millis() - now > 5)
            return;
    }

    // time out
    result = EXPECT_TIMEOUT;
}