/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "xpcprivate.h"

#ifdef XP_WIN
#include <windows.h>
#endif

static void DebugDump(const char* fmt, ...)
{
  char buffer[2048];
  va_list ap;
  va_start(ap, fmt);
#ifdef XPWIN
  _vsnprintf(buffer, sizeof(buffer), fmt, ap);
#else
  vsnprintf(buffer, sizeof(buffer), fmt, ap);
#endif
  buffer[sizeof(buffer)-1] = '\0';
  va_end(ap);
#ifdef XP_WIN
  if (IsDebuggerPresent()) {
    OutputDebugStringA(buffer);
  }
#endif
  printf("%s", buffer);
}

JSBool
xpc_DumpJSStack(JSContext* cx, JSBool showArgs, JSBool showLocals, JSBool showThisProps)
{
    if (char* buf = xpc_PrintJSStack(cx, showArgs, showLocals, showThisProps)) {
        DebugDump("%s\n", buf);
        JS_smprintf_free(buf);
    }
    return true;
}

char*
xpc_PrintJSStack(JSContext* cx, JSBool showArgs, JSBool showLocals,
                 JSBool showThisProps)
{
    char* buf;
    JSExceptionState *state = JS_SaveExceptionState(cx);
    if (!state)
        DebugDump("%s", "Call to a debug function modifying state!\n");

    JS_ClearPendingException(cx);

    buf = JS::FormatStackDump(cx, nullptr, showArgs, showLocals, showThisProps);
    if (!buf)
        DebugDump("%s", "Failed to format JavaScript stack for dump\n");

    JS_RestoreExceptionState(cx, state);
    return buf;
}

/***************************************************************************/

static void
xpcDumpEvalErrorReporter(JSContext *cx, const char *message,
                         JSErrorReport *report)
{
    DebugDump("Error: %s\n", message);
}

JSBool
xpc_DumpEvalInJSStackFrame(JSContext* cx, uint32_t frameno, const char* text)
{
    if (!cx || !text) {
        DebugDump("%s", "invalid params passed to xpc_DumpEvalInJSStackFrame!\n");
        return false;
    }

    DebugDump("js[%d]> %s\n", frameno, text);

    uint32_t num = 0;

    JSAbstractFramePtr frame = JSNullFramePtr();

    JSBrokenFrameIterator iter(cx);
    while (!iter.done()) {
        if (num == frameno) {
            frame = iter.abstractFramePtr();
            break;
        }
        ++iter;
        num++;
    }

    if (!frame) {
        DebugDump("%s", "invalid frame number!\n");
        return false;
    }

    JSAutoRequest ar(cx);

    JSExceptionState* exceptionState = JS_SaveExceptionState(cx);
    JSErrorReporter older = JS_SetErrorReporter(cx, xpcDumpEvalErrorReporter);

    JS::RootedValue rval(cx);
    JSString* str;
    JSAutoByteString bytes;
    if (frame.evaluateInStackFrame(cx, text, strlen(text), "eval", 1, &rval) &&
        nullptr != (str = JS_ValueToString(cx, rval)) &&
        bytes.encodeLatin1(cx, str)) {
        DebugDump("%s\n", bytes.ptr());
    } else
        DebugDump("%s", "eval failed!\n");
    JS_SetErrorReporter(cx, older);
    JS_RestoreExceptionState(cx, exceptionState);
    return true;
}

/***************************************************************************/

JSTrapStatus
xpc_DebuggerKeywordHandler(JSContext *cx, JSScript *script, jsbytecode *pc,
                           jsval *rval, void *closure)
{
    static const char line[] =
    "------------------------------------------------------------------------\n";
    DebugDump("%s", line);
    DebugDump("%s", "Hit JavaScript \"debugger\" keyword. JS call stack...\n");
    xpc_DumpJSStack(cx, true, true, false);
    DebugDump("%s", line);
    return JSTRAP_CONTINUE;
}

JSBool xpc_InstallJSDebuggerKeywordHandler(JSRuntime* rt)
{
    return JS_SetDebuggerHandler(rt, xpc_DebuggerKeywordHandler, nullptr);
}