/*
 * Copyright 2005, Ingo Weinhold, bonefish@users.sf.net.
 * Distributed under the terms of the MIT License.
 */

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include <map>
#include <string>
#include <vector>

#include <debugger.h>
#include <image.h>
#include <syscalls.h>

#include "Context.h"
#include "MemoryReader.h"
#include "Syscall.h"
#include "TypeHandler.h"

using std::map;
using std::string;
using std::vector;

extern void get_syscalls0(vector<Syscall*> &syscalls);
extern void get_syscalls1(vector<Syscall*> &syscalls);
extern void get_syscalls2(vector<Syscall*> &syscalls);
extern void get_syscalls3(vector<Syscall*> &syscalls);
extern void get_syscalls4(vector<Syscall*> &syscalls);
extern void get_syscalls5(vector<Syscall*> &syscalls);
extern void get_syscalls6(vector<Syscall*> &syscalls);
extern void get_syscalls7(vector<Syscall*> &syscalls);
extern void get_syscalls8(vector<Syscall*> &syscalls);
extern void get_syscalls9(vector<Syscall*> &syscalls);
extern void get_syscalls10(vector<Syscall*> &syscalls);
extern void get_syscalls11(vector<Syscall*> &syscalls);
extern void get_syscalls12(vector<Syscall*> &syscalls);
extern void get_syscalls13(vector<Syscall*> &syscalls);
extern void get_syscalls14(vector<Syscall*> &syscalls);
extern void get_syscalls15(vector<Syscall*> &syscalls);
extern void get_syscalls16(vector<Syscall*> &syscalls);
extern void get_syscalls17(vector<Syscall*> &syscalls);
extern void get_syscalls18(vector<Syscall*> &syscalls);
extern void get_syscalls19(vector<Syscall*> &syscalls);

extern const char *__progname;
static const char *kCommandName = __progname;

// usage
static const char *kUsage =
"Usage: %s [ <options> ] [ <thread or team ID> | <executable with args> ]\n"
"\n"
"Traces the the syscalls of a thread or a team. If an executable with\n"
"arguments is supplied, it is loaded and it's main thread traced.\n"
"\n"
"Options:\n"
"  -a             - Don't print syscall arguments.\n"
"  -c             - Don't colorize output.\n"
"  -d <name>      - Filter the types that have their contents retrieved.\n"
"                   <name> is one of: strings, enums, simple, complex or\n"
"                                     pointer_values\n"
"  -f             - Fast mode. Syscall arguments contents aren't retrieved.\n"
"  -h, --help     - Print this text.\n"
"  -i             - Print integers in decimal format instead of hexadecimal.\n"
"  -l             - Also trace loading the excecutable. Only considered when\n"
"                   an executable is provided.\n"
"  -r             - Don't print syscall return values.\n"
"  -s             - Also trace all threads spawned by the supplied thread,\n"
"                   respectively the loaded executable's main thread.\n"
"  -T             - Trace all threads of the supplied or loaded executable's\n"
"                   team. If an ID is supplied, it is interpreted as a team\n"
"                   ID.\n"
"  -o <file>      - directs output into the specified file.\n"
"  -S             - prints output to serial debug line.\n"
;

// terminal color escape sequences
// (http://www.dee.ufcg.edu.br/~rrbrandt/tools/ansi.html)
static const char *kTerminalTextNormal	= "\33[0m";
static const char *kTerminalTextRed		= "\33[31m";
static const char *kTerminalTextMagenta	= "\33[35m";


// command line args
static int sArgc;
static const char *const *sArgv;

// syscalls
static vector<Syscall*>			sSyscallVector;
static map<string, Syscall*>	sSyscallMap;

// print_usage
void
print_usage(bool error)
{
	// print usage
	fprintf((error ? stderr : stdout), kUsage, kCommandName);
}

// print_usage_and_exit
static
void
print_usage_and_exit(bool error)
{
	print_usage(error);
	exit(error ? 1 : 0);
}

// get_id
static
bool
get_id(const char *str, int32 &id)
{
	int32 len = strlen(str);
	for (int32 i = 0; i < len; i++) {
		if (!isdigit(str[i]))
			return false;
	}

	id = atol(str);
	return true;
}

// find_program
static
status_t
find_program(const char *programName, string &resolvedPath)
{
    // If the program name is absolute, then there's nothing to do.
    // If the program name consists of more than one path element, then we
    // consider it a relative path and don't search in PATH either.
    if (*programName == '/' || strchr(programName, '/')) {
        resolvedPath = programName;
        return B_OK;
    }

    // get the PATH environment variable
    const char *paths = getenv("PATH");
    if (!paths)
        return B_ENTRY_NOT_FOUND;

    // iterate through the paths
    do {
        const char *pathEnd = strchr(paths, ':');
        int pathLen = (pathEnd ? pathEnd - paths : strlen(paths));

        // We skip empty paths.
        if (pathLen > 0) {
            // get the program path
            string path(paths, pathLen);
            path += "/";
            path += programName;

            // stat() the path to be sure, there is a file
            struct stat st;
            if (stat(path.c_str(), &st) == 0 && S_ISREG(st.st_mode)) {
            	resolvedPath = path;
                return B_OK;
            }
        }

        paths = (pathEnd ? pathEnd + 1 : NULL);
    } while (paths);

    // not found in PATH
    return B_ENTRY_NOT_FOUND;
}

// load_program
thread_id
load_program(const char *const *args, int32 argCount, bool traceLoading)
{
	// clone the argument vector so that we can change it
	const char **mutableArgs = new const char*[argCount];
	for (int i = 0; i < argCount; i++)
		mutableArgs[i] = args[i];

	// resolve the program path
	string programPath;
	status_t error = find_program(args[0], programPath);
	if (error != B_OK)
		return error;
	mutableArgs[0] = programPath.c_str();

	// count environment variables
	int envCount = 0;
	while (environ[envCount] != NULL)
		envCount++;

	// load the program
	error = _kern_load_image(argCount, mutableArgs, envCount,
		(const char**)environ, B_NORMAL_PRIORITY,
		(traceLoading ? 0 : B_WAIT_TILL_LOADED));

	delete[] mutableArgs;

	return error;
}

// set_team_debugging_flags
static
void
set_team_debugging_flags(port_id nubPort, int32 flags)
{
	debug_nub_set_team_flags message;
	message.flags = flags;

	while (true) {
		status_t error = write_port(nubPort, B_DEBUG_MESSAGE_SET_TEAM_FLAGS,
			&message, sizeof(message));
		if (error == B_OK)
			return;

		if (error != B_INTERRUPTED) {
			fprintf(stderr, "%s: Failed to set team debug flags: %s\n",
				kCommandName, strerror(error));
			exit(1);
		}
	}
}

// set_thread_debugging_flags
static
void
set_thread_debugging_flags(port_id nubPort, thread_id thread, int32 flags)
{
	debug_nub_set_thread_flags message;
	message.thread = thread;
	message.flags = flags;

	while (true) {
		status_t error = write_port(nubPort, B_DEBUG_MESSAGE_SET_THREAD_FLAGS,
			&message, sizeof(message));
		if (error == B_OK)
			return;

		if (error != B_INTERRUPTED) {
			fprintf(stderr, "%s: Failed to set thread debug flags: %s\n",
				kCommandName, strerror(error));
			exit(1);
		}
	}
}

// continue_thread
static
void
continue_thread(port_id nubPort, thread_id thread)
{
	debug_nub_continue_thread message;
	message.thread = thread;
	message.handle_event = B_THREAD_DEBUG_HANDLE_EVENT;
	message.single_step = false;

	while (true) {
		status_t error = write_port(nubPort, B_DEBUG_MESSAGE_CONTINUE_THREAD,
			&message, sizeof(message));
		if (error == B_OK)
			return;

		if (error != B_INTERRUPTED) {
			fprintf(stderr, "%s: Failed to run thread %ld: %s\n",
				kCommandName, thread, strerror(error));
			exit(1);
		}
	}
}

// get_syscall
Syscall *
get_syscall(const char *name)
{
	map<string, Syscall *>::const_iterator i = sSyscallMap.find(name);
	if (i == sSyscallMap.end())
		return NULL;

	return i->second;
}

// patch_syscalls
static void
patch_syscalls()
{
	// instead of having this done here manually we should either add the
	// patching step to gensyscalls also manually or add metadata to
	// kernel/syscalls.h and have it parsed automatically
	extern void patch_ioctl();

	patch_ioctl();
}

// init_syscalls
static
void
init_syscalls()
{
	// init the syscall vector
	get_syscalls0(sSyscallVector);
	get_syscalls1(sSyscallVector);
	get_syscalls2(sSyscallVector);
	get_syscalls3(sSyscallVector);
	get_syscalls4(sSyscallVector);
	get_syscalls5(sSyscallVector);
	get_syscalls6(sSyscallVector);
	get_syscalls7(sSyscallVector);
	get_syscalls8(sSyscallVector);
	get_syscalls9(sSyscallVector);
	get_syscalls10(sSyscallVector);
	get_syscalls11(sSyscallVector);
	get_syscalls12(sSyscallVector);
	get_syscalls13(sSyscallVector);
	get_syscalls14(sSyscallVector);
	get_syscalls15(sSyscallVector);
	get_syscalls16(sSyscallVector);
	get_syscalls17(sSyscallVector);
	get_syscalls18(sSyscallVector);
	get_syscalls19(sSyscallVector);

	// init the syscall map
	int32 count = sSyscallVector.size();
	for (int32 i = 0; i < count; i++) {
		Syscall *syscall = sSyscallVector[i];
		sSyscallMap[syscall->Name()] = syscall;
	}

	patch_syscalls();
}

// print_to_string
static
void
print_to_string(char **_buffer, int32 *_length, const char *format, ...)
{
	va_list list;
	va_start(list, format);
	ssize_t length = vsnprintf(*_buffer, *_length, format, list);
	va_end(list);

	*_buffer += length;
	*_length -= length;
}

// print_syscall
static
void
print_syscall(FILE *outputFile, debug_post_syscall &message,
	MemoryReader &memoryReader, bool printArguments, uint32 contentsFlags,
	bool printReturnValue, bool colorize, bool decimal)
{
	char buffer[4096], *string = buffer;
	int32 length = (int32)sizeof(buffer);
	int32 syscallNumber = message.syscall;
	Syscall *syscall = sSyscallVector[syscallNumber];

	Context ctx(syscall, (char *)message.args, memoryReader,
		    contentsFlags, decimal);

	// print syscall name
	if (colorize) {
		print_to_string(&string, &length, "[%6ld] %s%s%s(",
			message.origin.thread, kTerminalTextRed, syscall->Name().c_str(),
			kTerminalTextNormal);
	} else {
		print_to_string(&string, &length, "[%6ld] %s(",
			message.origin.thread, syscall->Name().c_str());
	}

	// print arguments
	if (printArguments) {
		int32 count = syscall->CountParameters();
		for (int32 i = 0; i < count; i++) {
			// get the value
			Parameter *parameter = syscall->ParameterAt(i);
			TypeHandler *handler = parameter->Handler();
			::string value =
				handler->GetParameterValue(ctx, parameter,
						ctx.GetValue(parameter));

			print_to_string(&string, &length, (i > 0 ? ", %s" : "%s"),
				value.c_str());
		}
	}

	print_to_string(&string, &length, ")");

	// print return value
	if (printReturnValue) {
		Type *returnType = syscall->ReturnType();
		TypeHandler *handler = returnType->Handler();
		::string value = handler->GetReturnValue(ctx, message.return_value);
		if (value.length() > 0) {
			print_to_string(&string, &length, " = %s", value.c_str());

			// if the return type is status_t or ssize_t, print human-readable
			// error codes
			if (returnType->TypeName() == "status_t"
					|| (returnType->TypeName() == "ssize_t"
					 || returnType->TypeName() == "int")
					&& message.return_value < 0) {
				print_to_string(&string, &length, " %s", strerror(message.return_value));
			}
		}
	}

	if (colorize) {
		print_to_string(&string, &length, " %s(%lld us)%s\n", kTerminalTextMagenta,
			message.end_time - message.start_time, kTerminalTextNormal);
	} else {
		print_to_string(&string, &length, " (%lld us)\n",
			message.end_time - message.start_time);
	}

//for (int32 i = 0; i < 16; i++) {
//	if (i % 4 == 0) {
//		if (i > 0)
//			printf("\n");
//		printf("  ");
//	} else
//		printf(" ");
//	printf("%08lx", message.args[i]);
//}
//printf("\n");

	// output either to file or serial debug line
	if (outputFile != NULL)
		fwrite(buffer, sizeof(buffer) - length, 1, outputFile);
	else
		_kern_debug_output(buffer);
}


// main
int
main(int argc, const char *const *argv)
{
	sArgc = argc;
	sArgv = argv;

	// parameters
	const char *const *programArgs = NULL;
	int32 programArgCount = 0;
	bool printArguments = true;
	bool colorize = true;
	uint32 contentsFlags = 0;
	bool decimalFormat = false;
	bool fastMode = false;
	bool traceLoading = false;
	bool printReturnValues = true;
	bool traceChildThreads = false;
	bool traceTeam = false;
	bool serialOutput = false;
	FILE *outputFile = stdout;

	// parse arguments
	for (int argi = 1; argi < argc; argi++) {
		const char *arg = argv[argi];
		if (arg[0] == '-') {
			// ToDo: improve option parsing so that ie. "-rsf" would also work
			if (strcmp(arg, "-h") == 0 || strcmp(arg, "--help") == 0) {
				print_usage_and_exit(false);
			} else if (strcmp(arg, "-a") == 0) {
				printArguments = false;
			} else if (strcmp(arg, "-c") == 0) {
				colorize = false;
			} else if (strcmp(arg, "-d") == 0) {
				const char *what = NULL;

				if (arg[2] == '\0'
					&& argi + 1 < argc && argv[argi + 1][0] != '-') {
					// next arg is what
					what = argv[++argi];
				} else
					print_usage_and_exit(true);

				if (strcasecmp(what, "strings") == 0)
					contentsFlags |= Context::STRINGS;
				else if (strcasecmp(what, "enums") == 0)
					contentsFlags |= Context::ENUMERATIONS;
				else if (strcasecmp(what, "simple") == 0)
					contentsFlags |= Context::SIMPLE_STRUCTS;
				else if (strcasecmp(what, "complex") == 0)
					contentsFlags |= Context::COMPLEX_STRUCTS;
				else if (strcasecmp(what, "pointer_values") == 0)
					contentsFlags |= Context::POINTER_VALUES;
				else {
					fprintf(stderr, "%s: Unknown content filter `%s'\n",
						kCommandName, what);
					exit(1);
				}
			} else if (strcmp(arg, "-f") == 0) {
				fastMode = true;
			} else if (strcmp(arg, "-i") == 0) {
				decimalFormat = true;
			} else if (strcmp(arg, "-l") == 0) {
				traceLoading = true;
			} else if (strcmp(arg, "-r") == 0) {
				printReturnValues = false;
			} else if (strcmp(arg, "-s") == 0) {
				traceChildThreads = true;
			} else if (strcmp(arg, "-T") == 0) {
				traceTeam = true;
			} else if (strcmp(arg, "-S") == 0) {
				serialOutput = true;
				outputFile = NULL;
			} else if (strncmp(arg, "-o", 2) == 0) {
				// read filename
				const char *filename = NULL;
				if (arg[2] == '=') {
					// name follows
					filename = arg + 3;
				} else if (arg[2] == '\0'
					&& argi + 1 < argc && argv[argi + 1][0] != '-') {
					// next arg is name
					filename = argv[++argi];
				} else
					print_usage_and_exit(true);

				outputFile = fopen(filename, "w+");
				if (outputFile == NULL) {
					fprintf(stderr, "%s: Could not open `%s': %s\n",
						kCommandName, filename, strerror(errno));
					exit(1);
				}
			} else {
				print_usage_and_exit(true);
			}
		} else {
			programArgs = argv + argi;
			programArgCount = argc - argi;
			break;
		}
	}

	// check parameters
	if (!programArgs)
		print_usage_and_exit(true);

	if (fastMode)
		contentsFlags = 0;
	else if (contentsFlags == 0)
		contentsFlags = Context::ALL;

	// initialize our syscalls vector and map
	init_syscalls();

	// don't colorize the output, if we don't have a terminal
	if (outputFile == stdout)
		colorize = colorize && isatty(STDOUT_FILENO);
	else if (outputFile)
		colorize = false;

	// get thread/team to be debugged
	thread_id thread = -1;
	team_id team = -1;
	if (programArgCount > 1
		|| !get_id(*programArgs, (traceTeam ? team : thread))) {
		// we've been given an executable and need to load it
		thread = load_program(programArgs, programArgCount, traceLoading);
		if (thread < 0) {
			fprintf(stderr, "%s: Failed to start `%s': %s\n", kCommandName,
				programArgs[0], strerror(thread));
			exit(1);
		}
	}

	// get the team ID, if we have none yet
	if (team < 0) {
		thread_info threadInfo;
		status_t error = get_thread_info(thread, &threadInfo);
		if (error != B_OK) {
			fprintf(stderr, "%s: Failed to get info for thread %ld: %s\n",
				kCommandName, thread, strerror(error));
			exit(1);
		}
		team = threadInfo.team;
	}

	// create a debugger port
	port_id debuggerPort = create_port(10, "debugger port");
	if (debuggerPort < 0) {
		fprintf(stderr, "%s: Failed to create debugger port: %s\n",
			kCommandName, strerror(debuggerPort));
		exit(1);
	}

	// install ourselves as the team debugger
	port_id nubPort = install_team_debugger(team, debuggerPort);
	if (nubPort < 0) {
		fprintf(stderr, "%s: Failed to install team debugger: %s\n",
			kCommandName, strerror(nubPort));
		exit(1);
	}

	// set team debugging flags
	int32 teamDebugFlags = (traceTeam ? B_TEAM_DEBUG_POST_SYSCALL : 0);
	set_team_debugging_flags(nubPort, teamDebugFlags);

	// set thread debugging flags
	if (thread >= 0) {
		int32 threadDebugFlags = 0;
		if (!traceTeam) {
			threadDebugFlags = B_THREAD_DEBUG_POST_SYSCALL
				| (traceChildThreads
					? B_THREAD_DEBUG_SYSCALL_TRACE_CHILD_THREADS : 0);
		}
		set_thread_debugging_flags(nubPort, thread, threadDebugFlags);

		// resume the target thread to be sure, it's running
		resume_thread(thread);
	}

	MemoryReader memoryReader(nubPort);

	// debug loop
	while (true) {
		bool quitLoop = false;
		int32 code;
		debug_debugger_message_data message;
		ssize_t messageSize = read_port(debuggerPort, &code, &message,
			sizeof(message));

		if (messageSize < 0) {
			if (messageSize == B_INTERRUPTED)
				continue;

			fprintf(stderr, "%s: Reading from debugger port failed: %s\n",
				kCommandName, strerror(messageSize));
			exit(1);
		}

		switch (code) {
			case B_DEBUGGER_MESSAGE_POST_SYSCALL:
			{
				print_syscall(outputFile, message.post_syscall, memoryReader,
					      printArguments, contentsFlags, printReturnValues,
					      colorize, decimalFormat);

				break;
			}

			case B_DEBUGGER_MESSAGE_THREAD_DEBUGGED:
			case B_DEBUGGER_MESSAGE_DEBUGGER_CALL:
			case B_DEBUGGER_MESSAGE_BREAKPOINT_HIT:
			case B_DEBUGGER_MESSAGE_WATCHPOINT_HIT:
			case B_DEBUGGER_MESSAGE_SINGLE_STEP:
			case B_DEBUGGER_MESSAGE_PRE_SYSCALL:
			case B_DEBUGGER_MESSAGE_SIGNAL_RECEIVED:
			case B_DEBUGGER_MESSAGE_EXCEPTION_OCCURRED:
			case B_DEBUGGER_MESSAGE_TEAM_CREATED:
			case B_DEBUGGER_MESSAGE_THREAD_CREATED:
			case B_DEBUGGER_MESSAGE_THREAD_DELETED:
			case B_DEBUGGER_MESSAGE_IMAGE_CREATED:
			case B_DEBUGGER_MESSAGE_IMAGE_DELETED:
				break;

			case B_DEBUGGER_MESSAGE_TEAM_DELETED:
				// the debugged team is gone
				quitLoop = true;
				break;
		}

		if (quitLoop)
			break;

		// tell the thread to continue (only when there is a thread and the
		// message was synchronous)
		if (message.origin.thread >= 0 && message.origin.nub_port >= 0)
			continue_thread(message.origin.nub_port, message.origin.thread);
	}

	if (outputFile != NULL && outputFile != stdout)
		fclose(outputFile);

	return 0;
}