$CHECKING:OFF

SUB vwatch (localVariables AS _OFFSET)
    STATIC AS LONG ideHost, breakpointCount, skipCount, timeout, startLevel, lastLine
    STATIC AS LONG callStackLength, runToLine
    STATIC AS _BYTE pauseMode, stepOver, bypass, setNextLine
    STATIC buffer$, endc$
    DIM AS LONG i
    DIM AS _OFFSET address
    DIM AS _MEM m
    DIM start!, temp$, cmd$, value$, k&

    DECLARE LIBRARY
        SUB vwatch_stoptimers ALIAS stop_timers
        SUB vwatch_starttimers ALIAS start_timers
        SUB unlockvWatchHandle
    END DECLARE

    IF bypass THEN EXIT SUB

    vwatch_goto = 0

    IF ideHost = 0 THEN
        timeout = 10
        endc$ = "<END>"

        'initial setup
        GOSUB Connect

        'send this binary's path/exe name
        cmd$ = "me:" + COMMAND$(0)
        GOSUB SendCommand

        DO
            GOSUB GetCommand
            SELECT CASE cmd$
                CASE "vwatch"
                    IF value$ <> "ok" THEN
                        unlockvWatchHandle: CLOSE #ideHost
                        bypass = -1
                        EXIT SUB
                    END IF
                CASE "line count"
                    REDIM vwatch_breakpoints(CVL(value$)) AS _BYTE
                    REDIM vwatch_skiplines(CVL(value$)) AS _BYTE
                CASE "breakpoint count"
                    breakpointCount = CVL(value$)
                CASE "breakpoint list"
                    IF LEN(value$) \ 4 <> breakpointCount THEN
                        cmd$ = "quit:Communication error."
                        GOSUB SendCommand
                        unlockvWatchHandle: CLOSE #ideHost
                        bypass = -1
                        EXIT SUB
                    END IF
                    FOR i = 1 TO breakpointCount
                        temp$ = MID$(value$, i * 4 - 3, 4)
                        vwatch_breakpoints(CVL(temp$)) = -1
                    NEXT
                CASE "skip count"
                    skipCount = CVL(value$)
                CASE "skip list"
                    IF LEN(value$) \ 4 <> skipCount THEN
                        cmd$ = "quit:Communication error."
                        GOSUB SendCommand
                        unlockvWatchHandle: CLOSE #ideHost
                        bypass = -1
                        EXIT SUB
                    END IF
                    FOR i = 1 TO skipCount
                        temp$ = MID$(value$, i * 4 - 3, 4)
                        vwatch_skiplines(CVL(temp$)) = -1
                    NEXT
                CASE "run"
                    IF vwatch_breakpoints(vwatch_linenumber) THEN EXIT DO
                    pauseMode = 0
                    EXIT SUB
                CASE "break"
                    pauseMode = -1
                    EXIT DO
            END SELECT
        LOOP
    END IF

    IF vwatch_linenumber = 0 THEN
        GOSUB SendCallStack
        cmd$ = "quit:Program ended."
        GOSUB SendCommand
        unlockvWatchHandle: CLOSE #ideHost
        bypass = -1
        ideHost = 0
        EXIT SUB
    ELSEIF vwatch_linenumber = -1 THEN
        'report an error in the most recent line
        GOSUB SendCallStack
        cmd$ = "error:" + MKL$(lastLine)
        GOSUB SendCommand
        EXIT SUB
    ELSEIF vwatch_linenumber = -2 THEN
        'report a new sub/function has been "entered"
        IF LEN(vwatch_callstack) > 100000 THEN
            vwatch_callstack = ""
            callStackLength = 0
        END IF
        callStackLength = callStackLength + 1
        IF LEN(vwatch_callstack) THEN vwatch_callstack = vwatch_callstack + CHR$(0)
        vwatch_callstack = vwatch_callstack + vwatch_subname$ + ", line" + STR$(lastLine)
        EXIT SUB
    ELSEIF vwatch_linenumber = -3 THEN
        'handle STOP - instead of quitting, pause execution
        pauseMode = -1
        stepOver = 0
        EXIT SUB
    END IF

    IF vwatch_linenumber = lastLine AND setNextLine = 0 THEN EXIT SUB
    setNextLine = 0
    lastLine = vwatch_linenumber

    GOSUB GetCommand
    SELECT CASE cmd$
        CASE "break"
            pauseMode = -1
            stepOver = 0
            runToLine = 0
            cmd$ = ""
        CASE "set breakpoint"
            vwatch_breakpoints(CVL(value$)) = -1
            vwatch_skiplines(CVL(value$)) = 0
        CASE "clear breakpoint"
            vwatch_breakpoints(CVL(value$)) = 0
        CASE "set skip line"
            vwatch_skiplines(CVL(value$)) = -1
            vwatch_breakpoints(CVL(value$)) = 0
        CASE "clear skip line"
            vwatch_skiplines(CVL(value$)) = 0
        CASE "clear all breakpoints"
            REDIM vwatch_breakpoints(UBOUND(vwatch_breakpoints)) AS _BYTE
        CASE "clear all skips"
            REDIM vwatch_skiplines(UBOUND(vwatch_skiplines)) AS _BYTE
    END SELECT

    IF vwatch_skiplines(vwatch_linenumber) THEN vwatch_goto = -vwatch_linenumber: EXIT SUB

    IF stepOver = -1 AND vwatch_sublevel > startLevel AND vwatch_breakpoints(vwatch_linenumber) = 0 THEN
        EXIT SUB
    ELSEIF stepOver = -1 AND vwatch_sublevel = startLevel THEN
        stepOver = 0
        pauseMode = -1
    END IF

    IF runToLine > 0 AND runToLine <> vwatch_linenumber THEN
        EXIT SUB
    ELSEIF runToLine > 0 AND runToLine = vwatch_linenumber THEN
        pauseMode = -1
        runToLine = 0
    END IF

    IF vwatch_breakpoints(vwatch_linenumber) = 0 AND pauseMode = 0 THEN
        EXIT SUB
    END IF

    vwatch_stoptimers
    cmd$ = "line number:"
    IF vwatch_breakpoints(vwatch_linenumber) THEN cmd$ = "breakpoint:"
    cmd$ = cmd$ + MKL$(vwatch_linenumber)
    GOSUB SendCommand

    DO 'main loop
        SELECT CASE cmd$
            CASE "run"
                pauseMode = 0
                stepOver = 0
                vwatch_starttimers
                EXIT SUB
            CASE "run to line"
                pauseMode = 0
                stepOver = 0
                runToLine = CVL(value$)
                vwatch_starttimers
                EXIT SUB
            CASE "step"
                pauseMode = -1
                stepOver = 0
                EXIT SUB
            CASE "step over"
                pauseMode = -1
                stepOver = -1
                startLevel = vwatch_sublevel
                vwatch_starttimers
                EXIT SUB
            CASE "step out"
                pauseMode = -1
                stepOver = -1
                startLevel = vwatch_sublevel - 1
                vwatch_starttimers
                EXIT SUB
            CASE "free"
                unlockvWatchHandle: CLOSE #ideHost
                ideHost = 0
                bypass = -1
                vwatch_starttimers
                EXIT SUB
            CASE "set breakpoint"
                vwatch_breakpoints(CVL(value$)) = -1
                vwatch_skiplines(CVL(value$)) = 0
            CASE "clear breakpoint"
                vwatch_breakpoints(CVL(value$)) = 0
            CASE "clear all breakpoints"
                REDIM vwatch_breakpoints(UBOUND(vwatch_breakpoints)) AS _BYTE
            CASE "clear all skips"
                REDIM vwatch_skiplines(UBOUND(vwatch_skiplines)) AS _BYTE
            CASE "call stack"
                'send call stack history"
                GOSUB SendCallStack
            CASE "local"
                i = CVL(value$)
                address = localVariables + LEN(address) * i
                PRINT "Local"; i; "is at"; _MEMGET(m, address, _OFFSET)
            CASE "set next line"
                pauseMode = -1
                stepOver = 0
                setNextLine = -1
                vwatch_goto = CVL(value$)
                EXIT SUB
            CASE "set skip line"
                vwatch_skiplines(CVL(value$)) = -1
                vwatch_breakpoints(CVL(value$)) = 0
            CASE "clear skip line"
                vwatch_skiplines(CVL(value$)) = 0
        END SELECT

        GOSUB GetCommand
        _LIMIT 100
    LOOP

    vwatch_starttimers
    EXIT SUB

    Connect:
    DIM ideport$
    ideport$ = ENVIRON$("QB64DEBUGPORT")
    IF ideport$ = "" THEN bypass = -1: EXIT SUB

    start! = TIMER
    DO
        k& = _KEYHIT
        ideHost = _OPENCLIENT("QB64IDE:" + ideport$ + ":localhost")
        _LIMIT 30
    LOOP UNTIL k& = 27 OR ideHost <> 0 OR TIMER - start! > timeout
    IF ideHost = 0 THEN bypass = -1: EXIT SUB
    RETURN

    GetCommand:
    GET #ideHost, , temp$
    buffer$ = buffer$ + temp$

    IF INSTR(buffer$, endc$) THEN
        cmd$ = LEFT$(buffer$, INSTR(buffer$, endc$) - 1)
        buffer$ = MID$(buffer$, INSTR(buffer$, endc$) + LEN(endc$))

        IF INSTR(cmd$, ":") THEN
            value$ = MID$(cmd$, INSTR(cmd$, ":") + 1)
            cmd$ = LEFT$(cmd$, INSTR(cmd$, ":") - 1)
        ELSE
            value$ = ""
        END IF
    ELSE
        cmd$ = "": value$ = ""
    END IF
    RETURN

    SendCallStack:
    cmd$ = "call stack size:" + MKL$(callStackLength)
    GOSUB SendCommand
    cmd$ = "call stack:" + vwatch_callstack
    GOSUB SendCommand
    RETURN

    SendCommand:
    cmd$ = cmd$ + endc$
    PUT #ideHost, , cmd$
    cmd$ = ""
    RETURN
END SUB