CC = gcc
CFLAGS = -Wall -O3
CPPFLAGS = -DUSE_TCL_STUBS
LIBS = -ltclstub8.5

all: vfs_kitdll_data.so

vfs_kitdll_data.h: dir2c.tcl starpack.vfs
	./dir2c.tcl vfs_kitdll_data starpack.vfs > vfs_kitdll_data.h

vfs_kitdll.tcl.h: vfs_kitdll.tcl
	./stringify.tcl vfs_kitdll.tcl > vfs_kitdll.tcl.h

vfs_kitdll_data.o: vfs_kitdll_data.c vfs_kitdll_data.h vfs_kitdll.tcl.h

vfs_kitdll_data.so: vfs_kitdll_data.o
	$(CC) $(CPPFLAGS) $(CFLAGS) -rdynamic -shared $(LDFLAGS) -o vfs_kitdll_data.so vfs_kitdll_data.o $(LIBS)

clean:
	rm -f vfs_kitdll_data.so vfs_kitdll_data.o
	rm -f vfs_kitdll.tcl.h vfs_kitdll_data.h

.PHONY: clean

#! /usr/bin/env tclsh

if {[llength $argv] != 2} {
	puts stderr "Usage: dir2c <hashkey> <startdir>"
	puts stderr "Usage: kitdll <hashkey> <startdir>"

	exit 1
}

set hashkey [lindex $argv 0]
set startdir [lindex $argv 1]

	}
	return $file
}

proc recursive_glob {dir} {
	set children [glob -nocomplain -directory $dir *]

	set ret [list]
	set ret [list $dir]
	foreach child $children {
		unset -nocomplain childinfo
		catch {
			file stat $child childinfo
		}

		if {![info exists childinfo(type)]} {
			continue
		}

		if {$childinfo(type) == "directory"} {
			foreach add [recursive_glob $child] {
				lappend ret $add
			}

			lappend ret $child

			continue
		}

		if {$childinfo(type) != "file"} {
			continue
		}

		lappend ret $child
	}

	return $ret
}

proc dir2c_hash {path} {
	set h 0
	set g 0

# Convert a string into a C-style binary string
	for {set idx 0} {$idx < [string length $path]} {incr idx} {
		binary scan [string index $path $idx] H* char
		set char "0x$char"

## XXX: This function needs to be optimized
		set h [expr {($h << 4) + $char}]
		set g [expr {$h & 0xf0000000}]
		if {$g != 0} {
			set h [expr {($h & 0xffffffff) ^ ($g >> 24)}]
		}

		set h [expr {$h & ((~$g) & 0xffffffff)}]
	}

	return $h
}

proc stringify {data} {
	set ret "\""
	for {set idx 0} {$idx < [string length $data]} {incr idx} {
		binary scan [string index $data $idx] H* char

		append ret "\\x${char}"

		if {($idx % 20) == 0 && $idx != 0} {
			append ret "\"\n\""
		}
	}

	set ret [string trim $ret "\n\""]

	set ret "\"$ret\""

	return $ret
}

# This function must be kept in-sync with the generated C function below
proc kitdll_hash {path} {
	set h 0
	set g 0

	for {set idx 0} {$idx < [string length $path]} {incr idx} {
		binary scan [string index $path $idx] H* char
		set char "0x$char"

		set h [expr {($h << 4) + $char}]
		set g [expr {$h & 0xf0000000}]
		if {$g != 0} {
			set h [expr {($h & 0xffffffff) ^ ($g >> 24)}]
		}

		set h [expr {$h & ((~$g) & 0xffffffff)}]
	}

	return $h
}

# Generate list of files to include in output
set files [recursive_glob $startdir]

# Insert dummy entry cooresponding to C dummy entry
set files [linsert $files 0 "__DUMMY__"]

# Produce C89 compatible header
set cpp_tag "DIR2C_[string toupper $hashkey]"
set code_tag "dir2c_[string tolower $hashkey]"
set cpp_tag "KITDLL_[string toupper $hashkey]"
set code_tag "kitdll_[string tolower $hashkey]"

puts "#ifndef $cpp_tag"
puts "#  define $cpp_tag 1"
puts {
#  ifdef HAVE_STDC
#    ifndef HAVE_UNISTD_H
#      define HAVE_UNISTD_H 1
#    endif
#    ifndef HAVE_STRING_H
#      define HAVE_STRING_H 1
#    endif
#  endif
#  ifdef HAVE_UNISTD_H
puts {#  include <unistd.h>
#    include <unistd.h>
#  endif
#  ifdef HAVE_STRING_H
#    include <string.h>
#  endif

#  ifndef LOADED_DIR2C_COMMON
#    define LOADED_DIR2C_COMMON 1
#  ifndef LOADED_KITDLL_COMMON
#    define LOADED_KITDLL_COMMON 1

typedef enum {
	DIR2C_FILETYPE_FILE,
	DIR2C_FILETYPE_DIR
} dir2c_filetype_t;
	KITDLL_FILETYPE_FILE,
	KITDLL_FILETYPE_DIR
} kitdll_filetype_t;

struct dir2c_data {
	const char            *name;
	unsigned long         index;
	unsigned long         size;
	dir2c_filetype_t      type;
	const unsigned char   *data;
struct kitdll_data {
	const char *             name;
	unsigned long            index;
	unsigned long            size;
	kitdll_filetype_t        type;
	const unsigned char *    data;
};

static unsigned long dir2c_hash(const unsigned char *path) {
static unsigned long kitdll_hash(const unsigned char *path) {
	unsigned long i, h = 0, g = 0;

	for (i = 0; path[i]; i++) {
		h = (h << 4) + path[i];
		g = h & 0xf0000000;
		if (g) {
			h ^= (g >> 24);
		}
		h &= ((~g) & 0xffffffffLU);
	}
        
        return(h);
}

#  endif /* !LOADED_DIR2C_COMMON */}
#  endif /* !LOADED_KITDLL_COMMON */}
puts ""

puts "static struct dir2c_data ${code_tag}_data\[\] = {"
puts "static struct kitdll_data ${code_tag}_data\[\] = {"
puts "\t{"
puts "\t\t.name  = NULL,"
puts "\t\t.index = 0,"
puts "\t\t.type  = 0,"
puts "\t\t.size  = 0,"
puts "\t\t.data  = NULL,"
puts "\t},"
puts "\t{"
puts "\t\t.name  = \"\","
puts "\t\t.index = 1,"
puts "\t\t.type  = DIR2C_FILETYPE_DIR,"
puts "\t\t.size  = 0,"
puts "\t\t.data  = NULL,"
puts "\t},"
for {set idx 0} {$idx < [llength $files]} {incr idx} {
for {set idx 1} {$idx < [llength $files]} {incr idx} {
	set file [lindex $files $idx]
	set shortfile [shorten_file $startdir $file]

	unset -nocomplain finfo type
	file stat $file finfo

	switch -- $finfo(type) {
		"file" {
			set type "DIR2C_FILETYPE_FILE"
			set type "KITDLL_FILETYPE_FILE"
			set size $finfo(size)

			set fd [open $file]
			fconfigure $fd -translation binary
			set data [read $fd]
			close $fd

			set data [stringify $data]
			set data "(unsigned char *) [stringify $data]"
		}
		"directory" {
			set type "DIR2C_FILETYPE_DIR"
			set type "KITDLL_FILETYPE_DIR"
			set data "NULL"
			set size 0
		}
	}

	puts "\t{"
	puts "\t\t.name  = \"$shortfile\","
	puts "\t\t.index = [expr $idx + 2],"
	puts "\t\t.index = $idx,"
	puts "\t\t.type  = $type,"
	puts "\t\t.size  = $size,"
	puts "\t\t.data  = $data,"
	puts "\t},"
}
puts "};"
puts ""

puts "static unsigned long ${code_tag}_lookup_index(const char *path) {"
puts "\tswitch (dir2c_hash(path)) {"
puts "\tswitch (kitdll_hash((unsigned char *) path)) {"
puts "\t\tcase [dir2c_hash {}]:"
puts "\t\t\treturn(1);"

set seenhashes [list]
for {set idx 0} {$idx < [llength $files]} {incr idx} {
for {set idx 1} {$idx < [llength $files]} {incr idx} {
	set file [lindex $files $idx]
	set shortfile [shorten_file $startdir $file]
	set hash [dir2c_hash $shortfile]
	set hash [kitdll_hash $shortfile]

	if {[lsearch -exact $seenhashes $hash] != -1} {
		puts stderr "ERROR: Duplicate hash seen: $file ($hash), aborting"

		exit 1
	}
	lappend indexes_per_hash($hash) [list $shortfile $idx]
}

foreach {hash idx_list} [array get indexes_per_hash] {
	puts "\t\tcase $hash:"

	if {[llength $idx_list] == 1} {
		set idx [lindex $idx_list 0 1]

		puts "\t\t\treturn($idx);"
	} else {
		foreach idx_ent $idx_list {
			set shortfile [lindex $idx_ent 0]
			set idx [lindex $idx_ent 1]
	lappend seenhashes $hash

	puts "\t\tcase $hash:"

			puts "\t\t\tif (strcmp(path, \"$shortfile\") == 0) return($idx);"
		}
		puts "\t\t\tbreak;"
	puts "\t\t\treturn([expr $idx + 2]);"
	}
}

puts "\t}"
puts "\treturn(0);"
puts "}"
puts ""

puts "static struct dir2c_data *${code_tag}_getData(const char *path) {"
puts "\tunsigned long index;"
puts "static struct kitdll_data *${code_tag}_getData(const char *path, unsigned long index) {"
puts "\tif (path != NULL) {"
puts "\t\tindex = ${code_tag}_lookup_index(path);"
puts "\t}"
puts ""
puts "\tindex = ${code_tag}_lookup_index(path);"
puts "\tif (index == 0) {"
puts "\t\treturn(NULL);"
puts "\t}"
puts ""
puts "\tif (path != NULL) {"
puts "\t\tif (strcmp(path, ${code_tag}_data\[index\].name) != 0) {"
puts "\t\t\treturn(NULL);"
puts "\t\t}"
puts "\t}"
puts ""
puts "\treturn(&${code_tag}_data\[index\]);"
puts "}"
puts ""

puts "static unsigned long ${code_tag}_getChildren(const char *path, unsigned long *outbuf, unsigned long outbuf_count) {"
puts "\tunsigned long index;"
puts "\tunsigned long num_children = 0;"
puts ""
puts "\tindex = ${code_tag}_lookup_index(path);"
puts "\tif (index == 0) {"
puts "\t\treturn(0);"
puts "\t}"
puts ""
puts "\tif (${code_tag}_data\[index\].type != KITDLL_FILETYPE_DIR) {"
puts "\t\treturn(0);"
puts "\t}"
puts ""
puts "\tif (strcmp(path, ${code_tag}_data\[index\].name) != 0) {"
puts "\t\treturn(0);"
puts "\t}"
puts ""
puts "\tswitch (index) {"

unset -nocomplain children
array set children [list]
for {set idx 1} {$idx < [llength $files]} {incr idx} {
	set file [lindex $files $idx]
	set shortfile [shorten_file $startdir $file]

	unset -nocomplain finfo type
	file stat $file finfo

	if {$finfo(type) != "directory"} {
		continue;
	}

	# Determine which children are under this directory
	## Convert the current pathname to a regular expression that matches exactly
	set file_regexp [string map [list "\\" "\\\\" "." "\\." "\{" "\\\{" "\}" "\\\}" "*" "\\*"] $file]

	## Search for pathnames which start with exactly our name, followed by a slash
	## followed by no more slashes (direct descendants)
	set child_idx_list [lsearch -regexp -all $files "^${file_regexp}/\[^/\]*$"]

	set children($idx) $child_idx_list

	puts "\t\tcase $idx:"
	puts "\t\t\tnum_children = [llength $child_idx_list];"
	puts "\t\t\tbreak;"
	
}

puts "\t}"
puts ""
puts "\tif (outbuf == NULL) {"
puts "\t\treturn(num_children);"
puts "\t}"
puts ""
puts "\tif (num_children > outbuf_count) {"
puts "\t\tnum_children = outbuf_count;"
puts "\t}"
puts ""
puts "\tif (num_children == 0) {"
puts "\t\treturn(num_children);"
puts "\t}"
puts ""
puts "\tif (outbuf_count > num_children) {"
puts "\t\toutbuf_count = num_children;"
puts "\t}"
puts ""
puts "\tswitch (index) {"

foreach {idx child_idx_list} [array get children] {
	if {[llength $child_idx_list] == 0} {
		continue
	}

	puts "\t\tcase $idx:"
	puts "\t\t\tswitch(outbuf_count) {"

	for {set child_idx_idx [expr {[llength $child_idx_list] - 1}]} {$child_idx_idx >= 0} {incr child_idx_idx -1} {
		set child_idx [lindex $child_idx_list $child_idx_idx]

		puts "\t\t\t\tcase [expr {$child_idx_idx + 1}]:"
		puts "\t\t\t\t\toutbuf\[$child_idx_idx\] = $child_idx;"
	}

	puts "\t\t\t}"

	puts "\t\t\tbreak;"
}

puts "\t}"
puts ""
puts "\treturn(num_children);"
puts "}"
puts ""

puts "#endif /* !$cpp_tag */"

proc ::vfs::kitdll::Unmount {local} {
	vfs::filesystem unmount $local
}

# Implementation

## Filesystem Data
namespace eval ::vfs::kitdll::data {}
set ::vfs::kitdll::data(joe) "Test\n"
set {::vfs::kitdll::metadata()} [list type directory ino 0 mode 0555 nlink 2 uid 0 gid 0 size 0 atime 0 mtime 0 ctime 0]
set ::vfs::kitdll::metadata(joe) [list type file ino 1 mode 0444 nlink 1 uid 0 gid 0 size 5 atime 0 mtime 0 ctime 0]
set ::vfs::kitdll::metadata(sub) [list type directory ino 2 mode 0555 nlink 1 uid 0 gid 0 size 0 atime 0 mtime 0 ctime 0]
set ::vfs::kitdll::metadata(sub/sub2) [list type directory ino 3 mode 0555 nlink 1 uid 0 gid 0 size 0 atime 0 mtime 0 ctime 0]

proc ::vfs::kitdll::data::getData {hashkey file {start 0} {end "end"}} {
	if {![info exists ::vfs::kitdll::data($file)]} {
		return -code error "Invalid operation"
	}

	return [string range $::vfs::kitdll::data($file) $start $end]
}

proc ::vfs::kitdll::data::getMetadata {hashkey file} {
	if {![info exists ::vfs::kitdll::metadata($file)]} {
		return -code error "No such file"
	}

	return $::vfs::kitdll::metadata($file)
}

proc ::vfs::kitdll::data::getChildren {hashkey directory} {
	set pattern [file join $directory {[^/]*}]

	set children [array names ::vfs::kitdll::metadata -regexp "^${pattern}\$"]

	set newchildren [list]
	foreach child $children {
		if {$child == ""} {
			continue
		}

		set tail [lindex [split $child /] end]

		lappend newchildren $tail
	}

	return $newchildren
}

## VFS and Chan I/O
### Dispatchers
proc ::vfs::kitdll::vfshandler {hashkey subcmd args} {
	set cmd $args
	set cmd [linsert $cmd 0 "::vfs::kitdll::vfsop_${subcmd}" $hashkey]

	return [eval $cmd]

		}

		unset -nocomplain metadata
		catch {
			array set metadata [::vfs::kitdll::data::getMetadata $hashkey $child]
		}

		if {[string index $actualpath end] == "/"} {
			set child "${actualpath}${child}"
		if {[string index $root end] == "/"} {
			set child "${root}${child}"
		} else {
			set child "${actualpath}/${child}"
			set child "${root}/${child}"
		}
		if {[string index $child end] == "/"} {
			set child [string range $child 0 end-1]
		}

		if {![info exists metadata(type)]} {
			continue

	vfs::filesystem posixerror $::vfs::posix(EROFS)
}
proc ::vfs::kitdll::vfsop_utime {} {
	vfs::filesystem posixerror $::vfs::posix(EROFS)
}

package provide vfs::kitdll 1.0

::vfs::kitdll::Mount vfs_kitdll_data /tmp

#define HAVE_STDC 1

#include <tcl.h>
#include <stdio.h>
#include <stdlib.h>

#include "vfs_kitdll_data.h"

typedef struct kitdll_data *(cmd_getData_t)(const char *, unsigned long);
typedef unsigned long (cmd_getChildren_t)(const char *, unsigned long *, unsigned long);

static cmd_getData_t *getCmdData(const char *hashkey) {
	/* XXX: TODO: Look up symbol using dlsym() */
	if (strcmp(hashkey, "vfs_kitdll_data") == 0) {
		return(kitdll_vfs_kitdll_data_getData);
	}

	return(NULL);
}

static cmd_getChildren_t *getCmdChildren(const char *hashkey) {
	/* XXX: TODO: Look up symbol using dlsym() */
	if (strcmp(hashkey, "vfs_kitdll_data") == 0) {
		return(kitdll_vfs_kitdll_data_getChildren);
	}

	return(NULL);
}

static int getMetadata(ClientData cd, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
	cmd_getData_t *cmd_getData;
	cmd_getChildren_t *cmd_getChildren;
	struct kitdll_data *finfo = NULL;
	Tcl_Obj *ret_list, *ret_list_items[20];
	unsigned long num_children;
	const char *hashkey;
	const char *file;

	if (objc != 3) {
		Tcl_SetResult(interp, "wrong # args: should be \"getMetadata hashKey fileName\"", NULL);

		return(TCL_ERROR);
	}

	hashkey = Tcl_GetString(objv[1]);
	file = Tcl_GetString(objv[2]);

	cmd_getData = getCmdData(hashkey);
	cmd_getChildren = getCmdChildren(hashkey);

	if (cmd_getData == NULL || cmd_getChildren == NULL) {
		Tcl_SetResult(interp, "No such hashkey", NULL);

		return(TCL_ERROR);
	}

	finfo = cmd_getData(file, 0);

	if (finfo == NULL) {
		Tcl_SetResult(interp, "No such file or directory", NULL);

		return(TCL_ERROR);
	}

	/* Values that can be derived from "finfo" */
	ret_list_items[0] = Tcl_NewStringObj("type", 4);
	ret_list_items[2] = Tcl_NewStringObj("mode", 4);
	ret_list_items[4] = Tcl_NewStringObj("nlink", 5);

	if (finfo->type == KITDLL_FILETYPE_DIR) {
		num_children = cmd_getChildren(file, NULL, 0);

		ret_list_items[1] = Tcl_NewStringObj("directory", 9);
		ret_list_items[3] = Tcl_NewLongObj(040555);
		ret_list_items[5] = Tcl_NewLongObj(num_children);
	} else {
		ret_list_items[1] = Tcl_NewStringObj("file", 4);
		ret_list_items[3] = Tcl_NewLongObj(0444);
		ret_list_items[5] = Tcl_NewLongObj(1);
	}

	ret_list_items[6] = Tcl_NewStringObj("ino", 3);
	ret_list_items[7] = Tcl_NewLongObj(finfo->index);

	ret_list_items[8] = Tcl_NewStringObj("size", 4);
	ret_list_items[9] = Tcl_NewLongObj(finfo->size);

	/* Dummy values */
	ret_list_items[10] = Tcl_NewStringObj("uid", 3);
	ret_list_items[11] = Tcl_NewStringObj("0", 1);

	ret_list_items[12] = Tcl_NewStringObj("gid", 3);
	ret_list_items[13] = Tcl_NewStringObj("0", 1);

	ret_list_items[14] = Tcl_NewStringObj("atime", 5);
	ret_list_items[15] = Tcl_NewStringObj("0", 1);

	ret_list_items[16] = Tcl_NewStringObj("mtime", 5);
	ret_list_items[17] = Tcl_NewStringObj("0", 1);

	ret_list_items[18] = Tcl_NewStringObj("ctime", 5);
	ret_list_items[19] = Tcl_NewStringObj("0", 1);

	ret_list = Tcl_NewListObj(sizeof(ret_list_items) / sizeof(ret_list_items[0]), ret_list_items);

	Tcl_SetObjResult(interp, ret_list);

	return(TCL_OK);
}

static int getData(ClientData cd, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
	if (objc < 3 || objc > 5) {
		Tcl_SetResult(interp, "wrong # args: should be \"getData hashKey fileName ?start? ?end?\"", NULL);

		return(TCL_ERROR);
	}
	return(TCL_ERROR);
}

static int getChildren(ClientData cd, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
	cmd_getChildren_t *cmd_getChildren;
	cmd_getData_t *cmd_getData;
	struct kitdll_data *finfo = NULL;
	unsigned long num_children, idx;
	unsigned long *children;
	const char *hashkey;
	const char *file;
	const char *child;
	Tcl_Obj *ret_list, *ret_curr_obj;

	if (objc != 3) {
		Tcl_SetResult(interp, "wrong # args: should be \"getChildren hashKey fileName\"", NULL);

		return(TCL_ERROR);
	}

	hashkey = Tcl_GetString(objv[1]);
	file = Tcl_GetString(objv[2]);

	cmd_getData = getCmdData(hashkey);
	cmd_getChildren = getCmdChildren(hashkey);

	if (cmd_getData == NULL || cmd_getChildren == NULL) {
		Tcl_SetResult(interp, "No such hashkey", NULL);

		return(TCL_ERROR);
	}

	finfo = cmd_getData(file, 0);

	if (finfo == NULL) {
		Tcl_SetResult(interp, "No such file or directory", NULL);

		return(TCL_ERROR);
	}

	if (finfo->type != KITDLL_FILETYPE_DIR) {
		Tcl_SetResult(interp, "Not a directory", NULL);

		return(TCL_ERROR);
	}

	num_children = cmd_getChildren(file, NULL, 0);

	if (num_children == 0) {
		/* Return immediately if there are no children */
		Tcl_SetResult(interp, "", NULL);

		return(TCL_OK);
	}

	ret_list = Tcl_NewObj();
	if (ret_list == NULL) {
		Tcl_SetResult(interp, "Failed to allocate new object", NULL);

		return(TCL_ERROR);
	}

	children = malloc(sizeof(*children) * num_children);

	num_children = cmd_getChildren(file, children, num_children);

	for (idx = 0; idx < num_children; idx++) {
		finfo = cmd_getData(NULL, children[idx]);

		if (finfo == NULL || finfo->name == NULL) {
			continue;
		}

		child = finfo->name;

		ret_curr_obj = Tcl_NewStringObj(child, strlen(child));

		Tcl_ListObjAppendList(interp, ret_list, ret_curr_obj);
	}

	free(children);

	Tcl_SetObjResult(interp, ret_list);

	return(TCL_OK);
}

int Vfs_kitdll_data_Init(Tcl_Interp *interp) {   
	Tcl_Command tclCreatComm_ret;
	int tclPkgProv_ret;

	tclCreatComm_ret = Tcl_CreateObjCommand(interp, "::vfs::kitdll::data::getMetadata", getMetadata, NULL, NULL);
	if (!tclCreatComm_ret) {
		return(TCL_ERROR);
	}

	tclCreatComm_ret = Tcl_CreateObjCommand(interp, "::vfs::kitdll::data::getData", getData, NULL, NULL);
	if (!tclCreatComm_ret) {
		return(TCL_ERROR);
	}

	tclCreatComm_ret = Tcl_CreateObjCommand(interp, "::vfs::kitdll::data::getChildren", getChildren, NULL, NULL);
	if (!tclCreatComm_ret) {
		return(TCL_ERROR);
	}

	tclPkgProv_ret = Tcl_PkgProvide(interp, "vfs::kitdll::data", "1.0");

	return(tclPkgProv_ret);
}