#define _XOPEN_SOURCE

#include <Xm/Xm.h>
#include <Xm/MainW.h>
#include <Xm/RowColumn.h>
#include <Xm/PushB.h>
#include <Xm/Text.h>
#include <Xm/Form.h>
#include <Xm/PanedW.h>
#include <Xm/TabStack.h>
#include <Xm/List.h>
#include <Xm/Frame.h>
#include <Xm/TextF.h>
#include <Xm/Separator.h>
#include <Xm/ScrolledW.h>
#include <Xm/LabelG.h>

#include <Xmd/Icon.h>
#include <Xmd/Buffer.h>
#include <Xmd/Exec.h>

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <ctype.h>
#include <sys/wait.h>

#include "icons/icon.xbm"

Widget createLabeledTextForm         (Widget, String, String, XmString);
Widget createScrolledInfoText        (Widget, String);
void   selectPackage                 (String);
void   updatePackageList             (void);
void   readPackageList               (FILE *);
void   handleListModeSelectionChange (Widget, XtPointer, XtPointer);
void   handlePackageSelectionChange  (Widget, XtPointer, XtPointer);
void   handleSearchQueryActivate     (Widget, XtPointer, XtPointer);
String parsePackageName              (String);
void parseInfoOutput (FILE *, String *, String *, String *, String *);

static XtAppContext application;
static Pixmap       iconPixmap;

static struct {
	Widget name;
	Widget description;
	Widget dependencies;
	Widget provides;
	Widget contents;
	String selected;
} packageInfo = { 0 };

static struct {
	Widget query;
	Widget list;
	Widget modeMenu;
	enum {
		viewModeWorld,
		viewModeInstalled,
		viewModeUpgradable,
		viewModeOrphaned,
		viewModeSearch
	} viewMode;
	XmString viewModeStrings[4];
} packageList = { 0 };

int main (int argc, char *argv[]) {
	Widget topLevel = XtVaAppInitialize (
		&application, "PackageManager",
		NULL, 0,
		&argc, argv,
		NULL,
		XmNtitle, "Package Manager",
		XmNiconName, "Package Manager",
		NULL);
	iconPixmap = XmdLoadBitmapIcon(topLevel, icon);
	XtVaSetValues (
		topLevel,
		XmNiconPixmap, iconPixmap,
		NULL);
	Widget window = XtVaCreateManagedWidget (
		"window", xmMainWindowWidgetClass, topLevel,
		NULL);
	Widget pane = XtVaCreateWidget (
		"pane", xmPanedWindowWidgetClass, window,
		XmNorientation, XmHORIZONTAL,
		NULL);
	
	/* menu bar */
	XmString fileString   = XmStringCreateLocalized("File");
	XmString systemString = XmStringCreateLocalized("System");
	XmString helpString   = XmStringCreateLocalized("Help");
	Widget menuBar = XmVaCreateSimpleMenuBar (
		window, "menuBar",
    		XmVaCASCADEBUTTON, fileString,   'F',
    		XmVaCASCADEBUTTON, systemString, 'S',
		XmVaCASCADEBUTTON, helpString,   'H',
		NULL);
	XmStringFree(fileString);
	XmStringFree(systemString);
	XmStringFree(helpString);
	XtManageChild(menuBar);
	
	/* package list pane */
	Widget packageListPane = XtVaCreateWidget (
		"packageListPane", xmFormWidgetClass, pane,
		XmNhorizontalSpacing, 4,
		XmNverticalSpacing,   4,
		XmNmarginHeight,      2,
		XmNmarginWidth,       2,
		NULL);
	XmString packageSearchLabelString = XmStringCreateLocalized("Search:");
	packageList.query = createLabeledTextForm (
		packageListPane,
		"packageSearchLabel",
		"packageSearchText",
		packageSearchLabelString);
	XmStringFree(packageSearchLabelString);
	XtAddCallback (
		packageList.query,
		XmNactivateCallback, handleSearchQueryActivate,
		NULL);
	XtVaSetValues (
		XtParent(packageList.query),
		XmNrightAttachment, XmATTACH_FORM,
		XmNtopAttachment,   XmATTACH_FORM,
		XmNleftAttachment,  XmATTACH_FORM,
		NULL);
	
	/* list mode selector */
	Widget listModeFrame = XtVaCreateWidget (
		"listModeFrame", xmFrameWidgetClass, packageListPane,
		XmNshadowType,       XmSHADOW_IN,
		XmNshadowThickness,  1,
		XmNleftAttachment,   XmATTACH_FORM,
		XmNrightAttachment,  XmATTACH_FORM,
		XmNbottomAttachment, XmATTACH_FORM,
		NULL);
	Widget listModeRc = XtVaCreateWidget (
		"listModeRc", xmRowColumnWidgetClass, listModeFrame,
		XmNmarginWidth,      0,
		XmNmarginHeight,     0,
		NULL);
	XmString listModeString           = XmStringCreateLocalized("List:");
	packageList.viewModeStrings[viewModeWorld]      = XmStringCreateLocalized("World");
	packageList.viewModeStrings[viewModeInstalled]  = XmStringCreateLocalized("Installed");
	packageList.viewModeStrings[viewModeUpgradable] = XmStringCreateLocalized("Upgradable");
	packageList.viewModeStrings[viewModeOrphaned]   = XmStringCreateLocalized("Orphaned");
	packageList.viewModeStrings[viewModeSearch]     = XmStringCreateLocalized("Search");
	packageList.modeMenu = XmVaCreateSimpleOptionMenu (
		listModeRc, "packageListMode",
		listModeString, 'L', 0, handleListModeSelectionChange,
		XmVaPUSHBUTTON, packageList.viewModeStrings[viewModeWorld],      'W', NULL, NULL,
		XmVaPUSHBUTTON, packageList.viewModeStrings[viewModeInstalled],  'I', NULL, NULL,
		XmVaPUSHBUTTON, packageList.viewModeStrings[viewModeUpgradable], 'U', NULL, NULL,
		XmVaPUSHBUTTON, packageList.viewModeStrings[viewModeOrphaned],   'O', NULL, NULL,
		XmVaPUSHBUTTON, packageList.viewModeStrings[viewModeSearch],     'S', NULL, NULL,
		XmNtearOffModel, XmTEAR_OFF_ENABLED,
		NULL);
	XmStringFree(listModeString);
	XtManageChild(packageList.modeMenu);
	XtManageChild(listModeFrame);
	XtManageChild(listModeRc);
	
	/* packageList */
	packageList.list = XmCreateScrolledList(packageListPane, "packageList", NULL, 0);
	XtVaSetValues (
		XtParent(packageList.list),
		XmNtopAttachment,    XmATTACH_WIDGET,
		XmNtopWidget,        XtParent(packageList.query),
		XmNleftAttachment,   XmATTACH_FORM,
		XmNrightAttachment,  XmATTACH_FORM,
		XmNbottomAttachment, XmATTACH_WIDGET,
		XmNbottomWidget,     listModeFrame,
		NULL);
	XtAddCallback (
		packageList.list,
		XmNbrowseSelectionCallback, handlePackageSelectionChange,
		NULL);
	XtManageChild(packageList.list);
	
	/* package viewer */
	Widget descriptionPane = XtVaCreateWidget (
		"descriptionPane", xmFormWidgetClass, pane,
		XmNhorizontalSpacing, 4,
		XmNverticalSpacing,   4,
		XmNmarginHeight,      2,
		XmNmarginWidth,       2,
		NULL);
	
	/* package actions */
	Widget packageActionsFrame = XtVaCreateWidget (
		"packageActionsFrame", xmFrameWidgetClass, descriptionPane,
		XmNshadowType,       XmSHADOW_OUT,
		XmNleftAttachment,   XmATTACH_FORM,
		XmNrightAttachment,  XmATTACH_FORM,
		XmNbottomAttachment, XmATTACH_FORM,
		NULL);
	Widget packageActionsRc = XtVaCreateWidget (
		"packageActionsRc", xmRowColumnWidgetClass, packageActionsFrame,
		XmNorientation, XmHORIZONTAL,
		NULL);
	XmString packageAddString = XmStringCreateLocalized("Install");
	Widget packageAdd = XtVaCreateManagedWidget (
		"packageAdd", xmPushButtonWidgetClass, packageActionsRc,
		XmNlabelString, packageAddString,
		NULL);
	XmStringFree(packageAddString);
	XmString packageDeleteString = XmStringCreateLocalized("Remove");
	XtVaCreateManagedWidget (
		"packageDelete", xmPushButtonWidgetClass, packageActionsRc,
		XmNlabelString, packageDeleteString,
		NULL);
	XmStringFree(packageDeleteString);
	XmString packageUpgradeString = XmStringCreateLocalized("Upgrade");
	XtVaCreateManagedWidget (
		"packageUpgrade", xmPushButtonWidgetClass, packageActionsRc,
		XmNlabelString, packageUpgradeString,
		NULL);
	XmStringFree(packageUpgradeString);
	XmString packageFixString = XmStringCreateLocalized("Fix");
	XtVaCreateManagedWidget (
		"packageFix", xmPushButtonWidgetClass, packageActionsRc,
		XmNlabelString, packageFixString,
		NULL);
	XmStringFree(packageFixString);
	XtManageChild(packageActionsRc);
	XtManageChild(packageActionsFrame);

	/* visually separate package description and actions */
	Widget descriptionSeparator = XtVaCreateManagedWidget (
		"descriptionSeparator", xmSeparatorWidgetClass, descriptionPane,
		XmNleftAttachment,   XmATTACH_FORM,
		XmNrightAttachment,  XmATTACH_FORM,
		XmNbottomAttachment, XmATTACH_WIDGET,
		XmNbottomWidget,     packageAdd,
		NULL);
		
	/* package description */
	packageInfo.name = XtVaCreateManagedWidget (
		"name", xmLabelGadgetClass, descriptionPane,
		XmNleftAttachment,   XmATTACH_FORM,
		XmNrightAttachment,  XmATTACH_FORM,
		XmNtopAttachment,    XmATTACH_FORM,
		NULL);
	Widget descriptionTabStack = XtVaCreateWidget (
		"descriptionTabStack", xmTabStackWidgetClass, descriptionPane,
		XmNleftAttachment,   XmATTACH_FORM,
		XmNrightAttachment,  XmATTACH_FORM,
		XmNtopAttachment,    XmATTACH_WIDGET,
		XmNtopWidget,        packageInfo.name,
		XmNbottomAttachment, XmATTACH_WIDGET,
		XmNbottomWidget,     descriptionSeparator,
		XmNtabMarginWidth,   0,
		XmNtabMarginHeight,  0,
		XmNtabLabelSpacing,  0,
		XmNmarginWidth,      4,
		XmNmarginHeight,     4,
		XmNtabMode,          XmTABS_STACKED,
		NULL);
	packageInfo.description  = createScrolledInfoText(descriptionTabStack, "Description");
	packageInfo.dependencies = createScrolledInfoText(descriptionTabStack, "Dependencies");
	packageInfo.provides     = createScrolledInfoText(descriptionTabStack, "Provides");
	packageInfo.contents     = createScrolledInfoText(descriptionTabStack, "Contents");
	XtManageChild(descriptionTabStack);

	/* final setup */

	XtManageChild(packageListPane);
	XtManageChild(descriptionPane);
	XtManageChild(pane);

	XtVaSetValues (
		window,
		XmNmenuBar,    menuBar,
		XmNworkWindow, pane,
		NULL);
	
	updatePackageList();
	selectPackage(NULL);
	
	XtRealizeWidget(topLevel);
	XtAppMainLoop(application);
}

Widget createLabeledTextForm (
	Widget parent,
	String labelName,
	String textName,
	XmString labelString
) {
	Widget form = XtVaCreateWidget (
    		"form",  xmFormWidgetClass, parent,
		XmNorientation,  XmHORIZONTAL,
		NULL);
	Widget label = XtVaCreateManagedWidget (
    		labelName,  xmLabelGadgetClass, form,
		XmNleftAttachment,   XmATTACH_FORM,
		XmNtopAttachment,    XmATTACH_FORM,
		XmNbottomAttachment, XmATTACH_FORM,
		XmNlabelString,      labelString,
		NULL);
	Widget text = XtVaCreateManagedWidget (
    		textName, xmTextWidgetClass, form,
		XmNleftAttachment,   XmATTACH_WIDGET,
		XmNleftWidget,       label,
		XmNtopAttachment,    XmATTACH_FORM,
		XmNrightAttachment,  XmATTACH_FORM,
		XmNbottomAttachment, XmATTACH_FORM,
		NULL);
	XtManageChild (form);
	return text;
}

Widget createScrolledInfoText (Widget parent, String name) {
	Widget scroll = XtVaCreateWidget (
		name, xmScrolledWindowWidgetClass, parent,
		NULL);
	Widget info = XtVaCreateManagedWidget (
		"info", xmTextWidgetClass, scroll,
		XmNrows,             10,
		XmNcolumns,          60,
		XmNpaneMinimum,      35,
		XmNeditMode,         XmMULTI_LINE_EDIT,
		XmNeditable,         False,
		XmNwordWrap,         True,
		XmNscrollHorizontal, False,
		NULL);
	XtManageChild(scroll);
	return info;
}

void selectPackage (String name) {
	if (packageInfo.selected) XtFree(packageInfo.selected);
	packageInfo.selected = name;
	
	XmString packageNameString = NULL;
	
	if (name == NULL) {
		packageNameString = XmStringCreateLocalized("No package selected");
		XtVaSetValues (
			packageInfo.description,
			XmNvalue, "",
			NULL);
	} else {
		/* instruct apk to describe package */
		pid_t child;
		FILE *stream = XmdVaPipedExecPath (
			"apk", &child, "r",
			"apk", "info", name, "-dswLPR", "--license",
			NULL);
		if (stream == NULL) {
			/* TODO: error popup */
			return;
		}

		/* parse data*/		
		String description  = NULL;
		String dependencies = NULL;
		String provides     = NULL;
		String contents     = NULL;
		parseInfoOutput (
			stream,
			&description, &dependencies,
			&provides, &contents);
		fclose(stream);
		waitpid(child, NULL, 0);
		
		/* set tab contents to parsed data */
		packageNameString = XmStringCreateLocalized(name);
		XtVaSetValues (
			packageInfo.description,
			XmNvalue, description,
			NULL);
		XtVaSetValues (
			packageInfo.dependencies,
			XmNvalue, dependencies,
			NULL);
		XtVaSetValues (
			packageInfo.provides,
			XmNvalue, provides,
			NULL);
		XtVaSetValues (
			packageInfo.contents,
			XmNvalue, contents,
			NULL);
		XtFree(description);
		XtFree(dependencies);
		XtFree(provides);
		XtFree(contents);
	}
	
	XtVaSetValues (
		packageInfo.name,
		XmNlabelString, packageNameString,
		NULL);
	XmStringFree(packageNameString);
}

void parseInfoOutput (
	FILE *stream,
	String *description,
	String *dependencies,
	String *provides,
	String *contents
) {
	char nullTerminator = 0;
	
	enum {
		stateSkipUntilSpace,
		stateGetHeading,
		stateGetSection
	} state = stateSkipUntilSpace;
	int consecutiveNewlines = 0;
	XmdBuffer *activeBuffer  = NULL;
	XmdBuffer *headingBuffer = NULL;
	
	XmdBuffer *descriptionBuffer  = XmdBufferNew(char);
	XmdBuffer *dependenciesBuffer = XmdBufferNew(char);
	XmdBuffer *providesBuffer     = XmdBufferNew(char);
	XmdBuffer *contentsBuffer     = XmdBufferNew(char);
	
	int ch;
	while ((ch = fgetc(stream)) != EOF) switch (state) {
	/* discard stream until there is a space */
	case stateSkipUntilSpace:
		if (ch == ' ') {
			headingBuffer = XmdBufferNew(char);
			state = stateGetHeading;
		}
		break;
		
	/* what is the next section about? */
	case stateGetHeading:
		if (ch == ':') {
			XmdBufferPush(headingBuffer,  &nullTerminator);
			String heading = XmdBufferBreak(headingBuffer);
			
			if (strcmp(heading, "depends on") == 0) {
				activeBuffer = dependenciesBuffer;
			} else if (strcmp(heading, "provides") == 0) {
				activeBuffer = providesBuffer;
			} else if (strcmp(heading, "contains") == 0) {
				activeBuffer = contentsBuffer;
			} else {
				activeBuffer = descriptionBuffer;
			}
			
			XtFree(heading);
			consecutiveNewlines = 1;
			state = stateGetSection;
			fgetc(stream); /* skip newline */
		} else {
			XmdBufferPush(headingBuffer, &ch);
		}
		break;
	
	/* read the section data into the active buffer */
	case stateGetSection:
		if (ch == '\n') {
			if (consecutiveNewlines > 0) {
				state = stateSkipUntilSpace;
				break;
			}
			consecutiveNewlines ++;
		} else {
			consecutiveNewlines = 0;
		}
		XmdBufferPush(activeBuffer, &ch);
		break;
	}
	
	XmdBufferPush(descriptionBuffer,  &nullTerminator);
	XmdBufferPush(dependenciesBuffer, &nullTerminator);
	XmdBufferPush(providesBuffer,     &nullTerminator);
	XmdBufferPush(contentsBuffer,     &nullTerminator);
	
	*description  = XmdBufferBreak(descriptionBuffer);
	*dependencies = XmdBufferBreak(dependenciesBuffer);
	*provides     = XmdBufferBreak(providesBuffer);
	*contents     = XmdBufferBreak(contentsBuffer);
}

void updatePackageList (void) {
	FILE *stream = NULL;
	pid_t  child   = 0;
	
	switch (packageList.viewMode) {
	case viewModeWorld:
		stream = fopen("/etc/apk/world", "r");
		break;
	case viewModeInstalled:
		stream = XmdVaPipedExecPath (
			"apk", &child, "r",
			"apk", "list", "--installed",
			NULL);
		break;
	case viewModeUpgradable:
		stream = XmdVaPipedExecPath (
			"apk", &child, "r",
			"apk", "list", "--upgradable",
			NULL);
		break;
	case viewModeOrphaned:
		stream = XmdVaPipedExecPath (
			"apk", &child, "r",
			"apk", "list", "--orphaned",
			NULL);
		break;
	case viewModeSearch:
		;String query = NULL;
		XtVaGetValues (
			packageList.query,
			XmNvalue, &query,
			NULL);
		stream = XmdVaPipedExecPath (
			"apk", &child, "r",
			"apk", "search", query,
			NULL);
		XtFree(query);
		break;
	}
	
	if (stream == NULL) {
		/* TODO: error popup */
		return;
	}
	
	readPackageList(stream);
	fclose(stream);
	if (child != 0) waitpid(child, NULL, 0);
}

void readPackageList (FILE *list) {
	String line       = NULL;
	size_t lineLength = 0;
	
	char packageName[256] = { 0 };
	
	XmdBuffer *itemsBuffer = XmdBufferNew(XmString);
	
	while (getline(&line, &lineLength, list) != -1) {
		sscanf(line, "%256s", packageName);
		free(line);
		line = NULL;
		XmString packageNameString = XmStringCreateLocalized(packageName);
		XmdBufferPush(itemsBuffer, &packageNameString);
	}
	
	Cardinal length = XmdBufferLength(itemsBuffer);
	XmStringTable items = (XmStringTable)(XmdBufferBreak(itemsBuffer));
	
	XtVaSetValues (
		packageList.list,
		XmNitemCount, length,
		XmNitems,     items,
		NULL);
	
	/* free everything */
	if (line) free(line);
	for (size_t index = 0; index < length; index ++) {
		XmStringFree(items[index]);
	}
	XtFree((String)(items));
}

void handleListModeSelectionChange (
	Widget    widget,
	XtPointer clientData,
	XtPointer callData
) {
	(void)(widget);
	(void)(callData);
	
	int selected = *(int *)(&clientData);
	packageList.viewMode = selected;
	updatePackageList();
}

void handlePackageSelectionChange (
	Widget    widget,
	XtPointer clientData,
	XtPointer callData
) {
	(void)(widget);
	(void)(clientData);
	
	XmListCallbackStruct *event = (XmListCallbackStruct*)(callData);
	if (event->event == NULL) return;
	
	String choice = (String)(XmStringUnparse (
		event->item,
		XmFONTLIST_DEFAULT_TAG,
		XmCHARSET_TEXT,
		XmCHARSET_TEXT,
		NULL, 0,
		XmOUTPUT_ALL));
	selectPackage(parsePackageName(choice));
	XtFree(choice);
}

void handleSearchQueryActivate (
	Widget    widget,
	XtPointer clientData,
	XtPointer callData
) {
	(void)(widget);
	(void)(clientData);
	(void)(callData);
	
	packageList.viewMode = viewModeSearch;
	
	/* FIXME do this by activating the appropriate button. that way we dont
	   have to call updatePackageList manually as well. */
	Widget button = XmOptionButtonGadget(packageList.modeMenu);
	XtVaSetValues (
		button,
		XmNlabelString, packageList.viewModeStrings[packageList.viewMode],
		NULL);
	
	updatePackageList();
}

String parsePackageName (String input) {
	XmdBuffer *output = XmdBufferNew(char);
	char ch;
	Boolean wasDash = False;
	for (size_t index = 0; (ch = input[index]); index ++) {
		if (wasDash && isdigit(ch)) {
			XmdBufferPop(output, NULL);
			break;
		} else {
			wasDash = ch == '-';
			XmdBufferPush(output, &ch);
		}
	}
	char nullTerminator = 0;
	XmdBufferPush(output, &nullTerminator);
	return XmdBufferBreak(output);
}