package require struct::list                              ; # Higher order list operations.
package require vc::tools::dot                            ; # User feedback. DOT export.
package require vc::tools::log                            ; # User feedback.
package require vc::tools::trouble                        ; # Error reporting.
package require vc::tools::misc                           ; # Text formatting.
package require vc::fossil::import::cvs::project::rev     ; # Project level changesets
package require vc::fossil::import::cvs::project::revlink ; # Cycle links.
package require vc::fossil::import::cvs::integrity        ; # State integrity checks.

# # ## ### ##### ######## ############# #####################
##

snit::type ::vc::fossil::import::cvs::cyclebreaker {
    # # ## ### ##### ######## #############
    ## Public API

	foreach cset $changesets {
	    foreach succ [$cset successors] {
		# Changesets may have dependencies outside of the
		# chosen set. These are ignored
		if {![$dg node exists $succ]} continue
		$dg arc insert $cset $succ
		if {$succ eq $cset} {
		    $cset loopcheck
		    trouble fatal "[$cset str] depends on itself"
		}
	    }
	}

	if {$log} {
	    log write 3 cyclebreaker "Has [nsp [llength [$dg arcs]] dependency dependencies]"
	}

	foreach cset $replacements {
	    foreach succ [$cset successors] {
		# The new changesets may have dependencies outside of
		# the chosen set. These are ignored
		if {![$dg node exists $succ]} continue
		$dg arc insert $cset $succ
		if {$succ eq $cset} {
		    $cset loopcheck
		    trouble fatal "[$cset str] depends on itself"
		}
	    }
	}
	foreach cset $pre {
	    foreach succ [$cset successors] {
		# Note that the arc may already exist in the graph. If
		# so ignore it. The new changesets may have
		# dependencies outside of the chosen set. These are

    # # ## ### ##### ######## #############
}

namespace eval ::vc::fossil::import::cvs {
    namespace export cyclebreaker
    namespace eval cyclebreaker {
	namespace eval project {
	    namespace import ::vc::fossil::import::cvs::integrity
	    namespace import ::vc::fossil::import::cvs::project::rev
	    namespace import ::vc::fossil::import::cvs::project::revlink
	}
	namespace import ::vc::tools::misc::*
	namespace import ::vc::tools::log
	namespace import ::vc::tools::trouble
	namespace import ::vc::tools::dot

    typemethod changesets {csets} {
	log write 4 integrity {Check database consistency}

	set n 0
	RevisionChangesets
	TagChangesets
	BranchChangesets
	trouble abort? ; # Avoid expensive check if anything found before

	LoopCheck $csets
	return
    }

    typemethof loopcheckon {} {
	set myloopcheck 1
	return
    }

    # # ## ### ##### ######## #############
    ## Internal methods

    proc AllButMeta {} {

				 WHERE VV.cid = UU.cid
				 AND   UU.fcount < VV.rcount)
		AND    T.tid = C.type
	    }
	return
    }

    proc LoopCheck {csets} {
	variable ::myloopcheck
	if {!$myloopcheck} return

	log write 4 integrity {Checking changesets for self-references}

	foreach cset $csets {
	    if {[$cset loopcheck]} {
		trouble fatal "[$cset str] depends on itself"
	    }
	}
	return
    }

    proc ___UnusedChangesetChecks___ {} {

	    set ok 0
	    set b "<$cstype $csid>"
	    trouble fatal "$fname <$revnr> [string map [list @ $b] $label]"
	}
	log write 5 integrity {\[[format %02d [incr n]]\] [expr {$ok ? "Ok    " : "Failed"}] ... $header}
	return
    }

    # # ## ### ##### ######## #############

    typevariable myloopcheck 0 ; # Boolean flag. Controls whether
				 # 'integrity changesets' looks for
				 # changesets with loops or not.
				 # Default is to not look for them.

    # # ## ### ##### ######## #############
    ## Configuration

    pragma -hasinstances   no ; # singleton
    pragma -hastypeinfo    no ; # no introspection
    pragma -hastypedestroy no ; # immortal

package require vc::tools::trouble                    ; # Error reporting.
package require vc::tools::log                        ; # User feedback.
package require vc::tools::misc                       ; # Misc. path reformatting.
package require vc::fossil::import::cvs::pass         ; # Pass management
package require vc::fossil::import::cvs::pass::collar ; # Pass I.
package require vc::fossil::import::cvs::repository   ; # Repository management
package require vc::fossil::import::cvs::state        ; # State storage
package require vc::fossil::import::cvs::integrity    ; # State integrity checks.
package require vc::fossil::import::cvs::project::sym ; # Project level symbols
package require vc::fossil::import::cvs::cyclebreaker ; # Breaking dependency cycles.

# # ## ### ##### ######## ############# #####################
##

snit::type ::vc::fossil::import::cvs::option {

    # --project
    # -v, --verbose
    # -q, --quiet
    # --state (conversion status, ala config.cache)
    # --trunk-only
    # --exclude, --force-tag, --force-branch
    # --batch
    # --loopcheck

    # -o, --output
    # --dry-run
    # --symbol-transform RE:XX

    # # ## ### ##### ######## #############
    ## Public API, Methods

		--trunk-only                { repository trunkonly! }
		--exclude                   { project::sym exclude     [Value arguments] }
		--force-tag                 { project::sym forcetag    [Value arguments] }
		--force-branch              { project::sym forcebranch [Value arguments] }
		--batch                     { log noprogress }
		--dots                      { cyclebreaker dotsto [Value arguments] }
		--watch                     { cyclebreaker watch  [Value arguments] }
		--loopcheck                 { integrity loopcheckon }
		default {
		    Usage $badoption$option\n$gethelp
		}
	    }
	}

	if {[llength $arguments] > 1} Usage

	trouble info "                               branch. Both project and symbol names"
	trouble info "                               are glob patterns."
	trouble info ""
	trouble info "    --dots PATH                Write the changeset graphs before, after,"
	trouble info "                               and during breaking the of cycles to the"
	trouble info "                               direcotry PATH, using GraphViz's dot format"
	trouble info ""
	trouble info "    --loopcheck                Activate the expensive search for change-"
	trouble info "                               with loops, i.e. depending on themselves."

	# --project, --cache
	# ...
	return
    }

    proc PrintVersion {} {

    namespace eval option {
	namespace import ::vc::tools::misc::striptrailingslash
	namespace import ::vc::fossil::import::cvs::pass
	namespace import ::vc::fossil::import::cvs::pass::collar
	namespace import ::vc::fossil::import::cvs::cyclebreaker
	namespace import ::vc::fossil::import::cvs::repository
	namespace import ::vc::fossil::import::cvs::state
	namespace import ::vc::fossil::import::cvs::integrity
	namespace eval project {
	    namespace import ::vc::fossil::import::cvs::project::sym
	}
	namespace import ::vc::tools::trouble
	namespace import ::vc::tools::log
    }
}

# # ## ### ##### ######## ############# #####################
## Ready

package provide vc::fossil::import::cvs::option 1.0
return

	    log write 8 csets {MAP- item <$key> $self = [$self str]}
	}
	set pos          [lsearch -exact $mychangesets $self]
	set mychangesets [lreplace $mychangesets $pos $pos]
	return
    }

    method loopcheck {} {
	log write 7 csets {Checking [$self str] /[llength $myitems]}

	if {![struct::set contains [$self successors] $self]} {
	    return 0
	}
	if {[log verbosity?] < 8} { return 1 }

	    log write 8 csets {MAKE: [lsort $fragmentitems]}

	    set fragment [$type %AUTO% $project $cstype $cssrc \
			      [Untag $fragmentitems $cstype]]
	    lappend newcsets $fragment
	    $fragment persist

	    if {[$fragment loopcheck]} {
		trouble fatal "[$fragment str] depends on itself"
	    }
	}

	trouble abort?
	return $newcsets
    }