Uninstall installed ports before restoring snapshot

Includes uninstalling all, those active or inactive

src/macports1.0/restore.tcl

@@ -9,11 +9,13 @@ package provide restore 1.0
 
 package require macports 1.0
 package require registry 1.0
+package require Pextlib 1.0
+package require registry_uninstall 2.0
 
 namespace eval restore {
-	
-	proc main {opts} {
-		# The main function. Calls each individual function that needs to be run.
+
+    proc main {opts} {
+        # The main function. Calls each individual function that needs to be run.
         #
         # Args:
         #           opts - options array.
@@ -26,11 +28,108 @@ namespace eval restore {
         array set options $opts
 
         if ([info exists options(ports_restore_snapshot-id)]) {
-        	# use that snapshot
+            # use that snapshot
+            set snapshot [fetch_snapshot options(ports_restore_snapshot-id)]
         } else {
-        	# TODO: ask if the user is fine with the latest snapshot, if 'yes'
-        	# use latest snapshot
+            # TODO: ask if the user is fine with the latest snapshot, if 'yes'
+            # use latest snapshot
+            set snapshot [fetch_latest_snapshot]
         }
 
-	}
-}
+        # fetch ports and variants now
+
+        # WILL WRITE FOR FETCHING AFTER DISCUSSING WITH BRAD
+        # ASSUMING I GET THE FINAL PORTLIST FOR NOW
+
+        # $portlist
+        uninstall_installed portlist
+
+        # TODO: CLEAN PARTIAL BUILDS STEP HERE
+
+    }
+
+    proc fetch_snapshot { snapshot_id } {
+
+    }
+
+    proc fetch_latest_snapshot {} {
+
+    }
+
+    proc sort_portlist_by_dependendents { portlist } {
+
+        # Sorts a list of port references such that dependents appear before
+        # the ports they depend on.
+        #
+        # Args:
+        #       portlist - the list of port references
+        #
+        # Returns:
+        #       the list in dependency-sorted order
+
+        foreach port $portlist {
+            set portname [$port name]
+            lappend ports_for_name($portname) $port
+
+            # Avoid adding ports in loop
+            if {![info exists dependents($portname)]} {
+                set dependents($portname) {}
+                foreach result [$port dependents] {
+                    lappend dependents($portname) [$result name]
+                }
+            }
+        }
+        set ret {}
+        foreach port $portlist {
+            sortdependents_helper $port ports_for_name dependents seen ret
+        }
+        return $ret
+    }
+
+    proc sortdependents_helper {port up_ports_for_name up_dependents up_seen up_retlist} {
+        upvar 1 $up_seen seen
+        if {![info exists seen($port)]} {
+            set seen($port) 1
+            upvar 1 $up_ports_for_name ports_for_name $up_dependents dependents $up_retlist retlist
+            foreach dependent $dependents([$port name]) {
+                if {[info exists ports_for_name($dependent)]} {
+                    foreach entry $ports_for_name($dependent) {
+                        sortdependents_helper $entry ports_for_name dependents seen retlist
+                    }
+                }
+            }
+            lappend retlist $port
+        }
+    }
+
+    proc uninstall_installed { portlist } {
+
+        set formatted_portlist  [list]
+
+        set portlist [sort_portlist_by_dependendents $portlist]
+
+        if {[info exists macports::ui_options(questions_yesno)]} {
+
+            set retvalue [$macports::ui_options(questions_yesno) "Restoring a snapshot will first uninstall all the installed ports.
+            Would you like to continue?" {n} 0]
+
+            if {$retvalue == 0} {
+                foreach port $portlist {
+                    set name [$port name]
+                     ui_msg "Uninstalling: $name"
+
+                    try -pass_signal {
+                        # 'registry_uninstall' takes name, version, revision, variants and an options list for a port
+                        registry_uninstall::uninstall [$port name] [$port version] [$port revision] [$port] variants {}
+                    } catch {{*} eCode eMessage} {
+                        ui_error "Error uninstalling $name: $eMessage"
+                    }
+                }
+            } else {
+                ui_msg "Not uninstalling ports."
+                return 1
+            }
+        }
+        return 0
+    }
+}