# This makes all keyboards into editors automatically, so a keyboard
# doesn't need to point at a real editor. May choose to change later, or
# exclude keyboards that opt out.
When /k/ is a keyboard with /...opts/ &\
     /nobody/ wishes /k/ does not create an editor {

    Wish tag $k is stabilized

    # Create a synthetic editor above the keyboard page.
    set editor [list $k editor]
    Claim $editor is an editor
    Wish $editor has a canvas
    When $k has resolved geometry /geom/ {
        Claim $editor has resolved geometry $geom
    }
    When the quad library is /quadLib/ & $k has quad /q/ {
        Claim $editor has quad [$quadLib move $q up 105%]
    }
    Claim $k has created editor $editor
    Claim $k is typing into $editor
}
When /k/ is a keyboard with /...opts/ &\
     /nobody/ claims /k/ has created editor /any/ &\
     /k/ points up at /editor/ & /editor/ is an editor with /...opts/ {

    Claim $k is typing into $editor
}

When the program save directory is /programDir/ &\
     the editor utils library is /utils/ {

# TODO: also don't hardcode this?
set margin [list 0.01 0.005 0.005 0.01] ;# CSS order (top, right, bottom, left)
set defaults { textScale 0.01 }

set editorLib [library create editorLib {margin defaults} {
    proc getAdvance {em} {
        # From NeomatrixCode.csv
        return $(0.5859375 * $em)
    }

    proc widthAndHeight {resolvedGeom} {
        set tagSize [dict get $resolvedGeom tagSize]
        set left [dict get $resolvedGeom left]
        set right [dict get $resolvedGeom right]
        set top [dict get $resolvedGeom top]
        set bottom [dict get $resolvedGeom bottom]

        set width $($left + $tagSize + $right)
        set height $($top + $tagSize + $bottom)

        return [list $width $height]
    }

    # given program and the editor options, figure out how many characters can
    # fit in this editor
    proc editorSizeInCharacters {resolvedGeom options} {
        variable margin

        set textScale [dict get $options scale]
        set advance [getAdvance $textScale]

        lassign [widthAndHeight $resolvedGeom] width height
        set width $($width - [lindex $margin 3] - $advance*2.5 - [lindex $margin 1])
        set height $($height - [lindex $margin 0] - [lindex $margin 2])

        set widthInCharacters $(int($width / $advance))
        set heightInCharacters $(int($height / $textScale))

        return [list $widthInCharacters $heightInCharacters]
    }
}]

When /someone/ claims /editor/ is an editor {
    Claim $editor is an editor with {*}$defaults
}

When /editor/ is an editor with /...options/ {
    # HACK: because we partial match
    if {![info exists options]} { return }

    set options [dict merge $defaults $options]

    Wish tag $editor is stabilized

    # Select which program the editor is viewing
    When $editor points up with length 0.3 at /program/ {
        Claim editor $editor has selected program $program
    }

    # Initial setup
    # Load initial text settings if not set
    When /nobody/ claims editor $editor has font options /...anything/ &\
         the saved holds are loaded {
        # Wait until all the saved holds are loaded, so we don't accidentally
        # overwrite a saved setting.
        set textScale [dict get $options textScale]
        Hold! -save -key font-options-of:$editor \
            Claim editor $editor has font options with scale $textScale
    }

    # We need the editor's resolved geometry to get its size.
    # We then use its size to figure out how many characters we can fit in it,
    # width-wise and height-wise.
    When $editor has resolved geometry /geom/ &\
         editor $editor has font options with /...options/ {
        Claim editor $editor has viewport size [$editorLib editorSizeInCharacters $geom $options]
    }

    # Load in defaults for the editor if it hasn't been initialized
    set results [Query! /somebody/ claims editor $editor has cursor /anything/]
    if {[llength $results] == 0} {
        Hold! -key editor-state-of:$editor {
            Claim editor $editor has cursor 0
            Claim editor $editor has max cursor x 0
            Claim editor $editor has viewport position [list 0 0]
            Claim editor $editor has selection anchor ""
            Claim editor $editor has undo stack {}
            Claim editor $editor has redo stack {}
            Claim editor $editor has last edit type ""
        }
    }

    set clipResults [Query! /somebody/ claims editor $editor has clipboard /anything/]
    if {[llength $clipResults] == 0} {
        Hold! -key clipboard-of:$editor Claim editor $editor has clipboard ""
    }

    # Load in initial program code (note, this buffer is shared between
    # all editor instances)
    When editor $editor has selected program /program/ &\
         /program/ has program code /programCode/ &\
         the saved holds are loaded {
        # Check if the code already exists.
        set results [Query! editor buffer for $program is /anything/]
        if {[llength $results] == 0} {
            Hold! -save -key buffer-for:$program \
                Claim editor buffer for $program is $programCode
        }
    }

    # Feedback: show that the editor is not active
    When /nobody/ wishes $editor is outlined green {
        Wish $editor is outlined blue
    }
}

Subscribe: keyboard /keyboard/ claims key Control_b is down with /...options/ {
    Notify: print code "# blank"
}

When /keyboard/ is a keyboard with path /kbPath/ /...anything/ &\
     /keyboard/ is typing into /editor/ &\
     /editor/ is an editor with /...anything/ &\
     editor /editor/ has selected program /program/ {
    Wish $editor is outlined green

    Subscribe: keyboard $kbPath claims key /key/ is /keyState/ with /...options/ {
        ForEach! editor $editor has viewport position /vpPos/ &\
                 editor $editor has viewport size /vpSize/ &\
                 editor buffer for $program is /code/ &\
                 editor $editor has max cursor x /maxCursorX/ &\
                 editor $editor has cursor /cursor/ &\
                 editor $editor has selection anchor /selAnchor/ &\
                 editor $editor has clipboard /clipboard/ &\
                 editor $editor has undo stack /undoStack/ &\
                 editor $editor has redo stack /redoStack/ &\
                 editor $editor has last edit type /lastEditType/ &\
                 editor $editor has font options with /...textOptions/ {
            lassign $vpPos vpX vpY
            lassign $vpSize vpWidth vpHeight

            if {$keyState == "up"} { return }

            # if this is true, the buffer will remove the hold for program code
            # (triggering a reinitialization)
            set resetBuffer false
            set isUndo false
            set isRedo false
            set origCode $code
            set origCursor $cursor
            set origMaxCursorX $maxCursorX

            set hasShift [dict exists $options shift]
            set isNavKey [expr {$key eq "Left" || $key eq "Right" || $key eq "Up" || $key eq "Down"}]

            # Handle selection replacement for text-modifying keys
            set selectionHandled false
            if {$selAnchor ne ""} {
                set selStart [min $selAnchor $cursor]
                set selEnd [max $selAnchor $cursor]

                if {[dict exists $options printable]} {
                    lassign [$utils replaceRange $code $selStart $selEnd [dict get $options printable]] code cursor maxCursorX
                    set selAnchor ""
                    set selectionHandled true
                } elseif {$key eq "Delete" || $key eq "Remove"} {
                    lassign [$utils replaceRange $code $selStart $selEnd ""] code cursor maxCursorX
                    set selAnchor ""
                    set selectionHandled true
                } elseif {$key eq "Return"} {
                    # Delete selection, then fall through to Return handler
                    lassign [$utils replaceRange $code $selStart $selEnd ""] code cursor maxCursorX
                    set selAnchor ""
                }
            }

            if {!$selectionHandled} {
                if {$hasShift && $isNavKey} {
                    # Shift+Arrow: extend selection
                    if {$selAnchor eq ""} { set selAnchor $cursor }
                    lassign [$utils handleNavigation $key $code $cursor $maxCursorX] cursor maxCursorX
                } elseif {[dict exists $options printable]} {
                    lassign [$utils insertText $code $cursor [dict get $options printable]] code cursor maxCursorX
                } else {
                    # Regular navigation clears selection
                    if {$isNavKey} { set selAnchor "" }

                    # general editor functionality
                    lassign [$utils handleNavigation $key $code $cursor $maxCursorX] cursor maxCursorX
                    lassign [$utils handleRemovalAndReturn $key $code $cursor $maxCursorX] code cursor maxCursorX

                    # specific editor functionality
                    switch $key {
                        Control_c {
                            if {$selAnchor ne ""} {
                                set clipText [$utils getSelectedText $code $selAnchor $cursor]
                                Hold! -key clipboard-of:$editor Claim editor $editor has clipboard $clipText
                            }
                        }
                        Control_x {
                            if {$selAnchor ne ""} {
                                set clipText [$utils getSelectedText $code $selAnchor $cursor]
                                Hold! -key clipboard-of:$editor Claim editor $editor has clipboard $clipText
                                set selStart [min $selAnchor $cursor]
                                set selEnd [max $selAnchor $cursor]
                                lassign [$utils replaceRange $code $selStart $selEnd ""] code cursor maxCursorX
                                set selAnchor ""
                            }
                        }
                        Control_v {
                            if {$clipboard ne ""} {
                                if {$selAnchor ne ""} {
                                    set selStart [min $selAnchor $cursor]
                                    set selEnd [max $selAnchor $cursor]
                                    lassign [$utils replaceRange $code $selStart $selEnd $clipboard] code cursor maxCursorX
                                    set selAnchor ""
                                } else {
                                    lassign [$utils replaceRange $code $cursor $cursor $clipboard] code cursor maxCursorX
                                }
                            }
                        }
                        Control_z {
                            if {[llength $undoStack] > 0} {
                                lappend redoStack [list $code $cursor $maxCursorX]
                                lassign [lindex $undoStack end] code cursor maxCursorX
                                set undoStack [lrange $undoStack 0 end-1]
                                set selAnchor ""
                                set isUndo true
                                set lastEditType ""
                            }
                        }
                        Control_y {
                            if {[llength $redoStack] > 0} {
                                lappend undoStack [list $code $cursor $maxCursorX]
                                lassign [lindex $redoStack end] code cursor maxCursorX
                                set redoStack [lrange $redoStack 0 end-1]
                                set selAnchor ""
                                set isRedo true
                                set lastEditType ""
                            }
                        }
                        Control_r {
                            set resetBuffer true
                        }
                        Control_s {
                            Notify: save code on editor $editor
                        }
                        Control_p {
                            Notify: print code $code

                            # Give the user some feedback
                            Hold! -key printing-alert:$editor \
                                Wish $editor is labelled "Printing!"
                            sleep 0.25
                            Hold! -key printing-alert:$editor {}
                        }
                        Control_underscore {
                            # ctrl and - (zoom out)
                            set textScale [dict get $textOptions scale]
                            set textScale [/ $textScale 1.1]

                            Hold! -save -key font-options-of:$editor \
                                Claim editor $editor has font options with scale $textScale
                        }
                        equal {
                            # Dunno why it registers as equal instead of Control_equal? It works regardless, lol
                            # ctrl and + (zoom in)
                            set textScale [dict get $textOptions scale]
                            set textScale [* $textScale 1.1]

                            Hold! -save -key font-options-of:$editor \
                                Claim editor $editor has font options with scale $textScale
                        }
                    }
                }
            }

            # Undo stack management with coalescing
            if {$code ne $origCode && !$isUndo && !$isRedo} {
                # Determine edit type for coalescing consecutive same-type edits
                if {[dict exists $options printable]} {
                    set editType "insert"
                } elseif {$key eq "Delete" || $key eq "Remove"} {
                    set editType "delete"
                } else {
                    set editType "other"
                }

                # Only push when edit type changes or for non-coalescable edits
                if {$editType ne $lastEditType || $editType eq "other"} {
                    lappend undoStack [list $origCode $origCursor $origMaxCursorX]
                    if {[llength $undoStack] > 50} {
                        set undoStack [lrange $undoStack end-49 end]
                    }
                }
                set lastEditType $editType

                # Any real edit clears the redo stack
                set redoStack {}
            } elseif {!$isUndo && !$isRedo} {
                # Navigation or no-op resets edit type (breaks coalescing)
                set lastEditType ""
            }

            if {$resetBuffer} {
                set cursor 0
                set maxCursorX 0
                set selAnchor ""
                set undoStack {}
                set redoStack {}
                set lastEditType ""

                # remove the edited code to restore the program to its original code
                Hold! -on builtin-programs/programs.folk -key new-code-for:$program {}
                file delete "$programDir/[regsub {\.folk$} $program {}].folk.edited"

                Hold! -save -key buffer-for:$program {
                    When $program has program code /originalCode/ {
                        Claim editor buffer for $program is $originalCode
                    }
                }
            } else {
                Hold! -save -key buffer-for:$program \
                    Claim editor buffer for $program is $code
            }

            lassign [$utils cursorToXy $code $cursor] cursorX cursorY
            # Be sure to have at least two characters on the left, so we can
            # see what we're removing.
            if {[- $cursorX 2] < $vpX} {
                set vpX [max 0 [- $cursorX 2]]
            }
            if {$cursorX >= $vpX + $vpWidth} {
                set vpX $($cursorX - $vpWidth)
            }
            if {$cursorY < $vpY} { set vpY $cursorY }
            if {$cursorY >= $vpY + $vpHeight - 1} {
                set vpY $($cursorY - $vpHeight + 1)
            }

            Hold! -keep 12ms -key editor-state-of:$editor {
                Claim editor $editor has viewport position [list $vpX $vpY]
                Claim editor $editor has cursor $cursor
                Claim editor $editor has max cursor x $maxCursorX
                Claim editor $editor has selection anchor $selAnchor
                Claim editor $editor has undo stack $undoStack
                Claim editor $editor has redo stack $redoStack
                Claim editor $editor has last edit type $lastEditType
            }
        }
    }
}

Subscribe: save code on editor /editor/ {
    ForEach! editor $editor has selected program /program/ &\
             editor buffer for /program/ is /programCode/ {
        Hold! -on builtin-programs/programs.folk -key new-code-for:$program \
            Wish program $program is replaced with \
            code $programCode editedTime [clock seconds]

        set programBase [regsub {\.folk$} $program ""]
        set editedPath "$programDir/[set programBase].folk.edited"
        file mkdir [file dirname $editedPath]
        set fp [open $editedPath w]
        puts -nonewline $fp $programCode
        close $fp

        # Give the user some feedback
        Hold! -key saved-alert:$editor \
            Wish $editor is labelled "Saved!"
        sleep 0.25
        Hold! -key saved-alert:$editor {}
    }
}

# calculate cursor position
When /editor/ is an editor with /...anything/ &\
     editor /editor/ has cursor /cursor/ &\
     editor /editor/ has selected program /program/ &\
     editor buffer for /program/ is /code/ &\
     editor /editor/ has viewport position /vpPos/ &\
     editor /editor/ has font options with /...textOptions/ {
    lassign $vpPos vpX vpY

    lassign [$utils cursorToXy $code $cursor] cursorX cursorY

    set textScale [dict get $textOptions scale]
    set advance [$editorLib getAdvance $textScale]

    set offsetX $(($cursorX - $vpX) * $advance)
    set offsetY $(($cursorY - $vpY) * $textScale)

    Claim editor $editor has cursor position [list $offsetX $offsetY]
}

# Draw text and cursor
When /editor/ is an editor with /...anything/ &\
     editor /editor/ has viewport position /vpPos/ &\
     editor /editor/ has viewport size /vpSize/ &\
     editor /editor/ has font options with /...fontOptions/ {
    lassign $vpPos vpX vpY
    lassign $vpSize vpWidth vpHeight

    set textScale [dict get $fontOptions scale]
    set advance [$editorLib getAdvance $textScale]

    When editor $editor has selected program /program/ &\
         editor buffer for /program/ is /code/ &\
         editor $editor has cursor /cursor/ &\
         editor $editor has cursor position /cursorPos/ &\
         editor $editor has selection anchor /selAnchor/ {
        set lineCount [min [- [llength [split $code "\n"]] $vpY] $vpHeight]
        set lineNumbers [$utils lineNumberView $vpY $lineCount]

        set marginLeft [lindex $margin 3]
        set lineNumbersRight $($marginLeft + $advance*1.5)
        Wish to draw text onto $editor with \
            position [list $lineNumbersRight [lindex $margin 0]] \
            text $lineNumbers \
            scale $textScale anchor topright font NeomatrixCode

        set text [$utils applyTextViewport $code $vpX $vpY $vpWidth $vpHeight]
        set pos [list [+ $lineNumbersRight $advance] [lindex $margin 0]]
        Wish to draw text onto $editor with \
            position $pos text $text \
            scale $textScale anchor topleft font NeomatrixCode

        # Draw selection highlight
        if {$selAnchor ne ""} {
            set rawStart [min $selAnchor $cursor]
            set rawEnd [max $selAnchor $cursor]
            lassign [$utils cursorToXy $code $rawStart] selStartX selStartY
            lassign [$utils cursorToXy $code $rawEnd] selEndX selEndY

            set lines [split $code "\n"]
            for {set ly $selStartY} {$ly <= $selEndY} {incr ly} {
                if {$ly < $vpY || $ly >= $vpY + $vpHeight} continue

                set lineLen [string length [lindex $lines $ly]]

                # Absolute column range for selection on this line
                if {$ly == $selStartY} {
                    set absStart $selStartX
                } else {
                    set absStart 0
                }
                if {$ly == $selEndY} {
                    set absEnd $selEndX
                } else {
                    set absEnd $lineLen
                }

                # Clip to viewport
                set absStart [max $absStart $vpX]
                set absEnd [min $absEnd [+ $vpX $vpWidth]]

                if {$absStart >= $absEnd} continue

                # Convert to display coordinates
                set dispStart [- $absStart $vpX]
                set dispEnd [- $absEnd $vpX]
                set dispRow [- $ly $vpY]

                set x0 $([lindex $pos 0] + $dispStart * $advance)
                set x1 $([lindex $pos 0] + $dispEnd * $advance)
                set y0 $([lindex $pos 1] + $dispRow * $textScale)
                set y1 $($y0 + $textScale)

                Wish to draw a quad onto $editor with \
                    p0 [list $x0 $y0] p1 [list $x1 $y0] \
                    p2 [list $x1 $y1] p3 [list $x0 $y1] \
                    color {0.2 0.4 0.8 0.7} layer -1
            }
        }

        set p1 [vec2 add $cursorPos $pos]
        set p2 [vec2 add $p1 [list 0 [* $textScale 1.2]]]
        set s [/ $textScale 6]
        Wish to draw a circle onto $editor with center $p1 radius $s thickness 0 color green filled true
        Wish to draw a line onto $editor with points [list $p1 $p2] width $s color green
    }
}


# end of library code
}