package require sha1
package require appfsd
package require platform
package require pki

# Functions specifically meant for users to replace as a part of configuration
namespace eval ::appfs::user {
	variable download_method "tcl"

	# User-replacable function to convert a hostname/hash/method to an URL
	proc construct_url {hostname hash method} {
		return "http://$hostname/appfs/$method/$hash"
	}

	# User-replaceable function get the home directory of the current user
	proc get_homedir {} {

		if {[info exists ::appfs::user::add_perms($sha1)]} {
			append perms $::appfs::user::add_perms($sha1)
		}

		return $perms
	}

	# User-replacable function to fetch a remote file
	proc download_file {url {outputChannel ""}} {
		switch -- $::appfs::user::download_method {
			"curl" {
				if {$outputChannel eq ""} {
					return [exec curl -sS -L -- $url]
				} else {
					exec curl -sS -L -- $url >@ $outputChannel

					return ""
				}
			}
			"tcl" {
				catch {
					if {$outputChannel eq ""} {
						set token [http::geturl $url]
						set retval [http::data $token]
					} else {
						set token [http::geturl $url -binary true -channel $outputChannel]
						set retval ""
					}
				} err

				if {![info exists token]} {
					return -code error "Unable to download \"$url\": $err"
				}

				set tokenCode [http::ncode $token]

				http::cleanup $token

				if {$tokenCode != "200"} {
					return -code error "Unable to download \"$url\": Site did not return a 200 (returned $tokenCode)"
				}

				if {![info exists retval]} {
					return -code error "Unable to download \"$url\": Site did not return proper data: $err"
				}

				return $retval
			}

		}

		return -code error "Unable to download"
	}
}

namespace eval ::appfs {
	variable cachedir "/tmp/appfs-cache"
	variable ttl 3600
	variable nttl 60
	variable trusted_cas [list]
	variable platform [::platform::generic]

	proc _hash_sep {hash {seps 4}} {
		for {set idx 0} {$idx < $seps} {incr idx} {
			append retval "[string range $hash [expr {$idx * 2}] [expr {($idx * 2) + 1}]]/"
		}
		append retval "[string range $hash [expr {$idx * 2}] end]"

		return $retval
	}

	proc _cachefile {url key method {keyIsHash 1}} {
		if {$keyIsHash && $method != "sha1"} {
			return -code error "Only SHA1 hashing method is supported"
		}

		set filekey $key
		if {$keyIsHash} {
			set filekey [_hash_sep $filekey]
		}

		set file [file join $::appfs::cachedir $filekey]

		file mkdir [file dirname $file]

		if {[file exists $file]} {
			return $file
		}

		set tmpfile "${file}.[expr {rand()}][clock clicks]"

		set fd [open $tmpfile "w"]
		fconfigure $fd -translation binary

		catch {


			::appfs::user::download_file $url $fd





		}

		close $fd

		if {$keyIsHash} {
			set hash [string tolower [sha1::sha1 -hex -file $tmpfile]]
		} else {
			set hash $key
		}

		if {$hash == $key} {
			file rename -force -- $tmpfile $file
		} else {
			file delete -force -- $tmpfile
		}

		return $file
	}

		db eval {CREATE INDEX IF NOT EXISTS sites_index ON sites (hostname);}
		db eval {CREATE INDEX IF NOT EXISTS packages_index ON packages (hostname, sha1, package, version, os, cpuArch);}
		db eval {CREATE INDEX IF NOT EXISTS files_index ON files (package_sha1, file_name, file_directory);}
	}

	proc download {hostname hash {method sha1}} {
		set url [::appfs::user::construct_url $hostname $hash $method]
		set file [_cachefile $url $hash $method]

		if {![file exists $file]} {
			return -code error "Unable to fetch (file does not exist: $file)"
		}

		return $file
	}

		if {$now < ($lastUpdate + $ttl)} {
			return COMPLETE
		}

		set url "http://$hostname/appfs/index"

		catch {


			set indexhash_data [::appfs::user::download_file $url]



		}

		# Note that we attempted to fetch this index and do not try
		# again for a while
		db eval {INSERT OR REPLACE INTO sites (hostname, lastUpdate, ttl) VALUES ($hostname, $now, $::appfs::nttl);}

		if {![info exists indexhash_data]} {