unless love.getVersion
    error "Pop.Box only supports LOVE versions >= 0.9.1"

import filesystem, graphics from love
import insert from table
import inheritsFromElement from require "#{...}/util"

path = ...

pop = {}

pop.elements = {}
pop.skins = {}
pop.events = {}

pop.screen = false  -- initialized in pop.load()
pop.focused = false

-- loads elements and skins, creates pop.screen (intended to only be called once at the beginning)
pop.load = ->
    elements = filesystem.getDirectoryItems "#{path}/elements"

    for i = 1, #elements
        -- only attempt to load lua files
        unless elements[i]\sub(-4) == ".lua"
            continue

        -- load into pop.elements table
        name = elements[i]\sub 1, -5
        pop.elements[name] = require "#{path}/elements/#{name}"

        if pop.elements[name].load
            pop.elements[name].load pop

        print "element loaded: \"#{name}\""

        -- create pop.element() wrapper if possible
        unless pop[name]
            if pop.elements[name].wrap
                pop[name] = pop.elements[name].wrap pop
            else
                pop[name] = (...) ->
                    return pop.create(name, ...)

            print "wrapper created: \"pop.#{name}()\""

    -- works just like above, except no wrappers
    skins = filesystem.getDirectoryItems "#{path}/skins"

    for i = 1, #skins
        unless skins[i]\sub(-4) == ".lua"
            continue

        name = skins[i]\sub 1, -5
        pop.skins[name] = require "#{path}/skins/#{name}"

        print "skin loaded: \"#{name}\""

    -- load extensions by just running them via require
    extensions = filesystem.getDirectoryItems "#{path}/extensions"

    for i = 1, #extensions
        unless extensions[i]\sub(-4) == ".lua"
            continue

        name = extensions[i]\sub 1, -5
        require "#{path}/extensions/#{name}"

        print "extension loaded: \"#{name}\""

    -- main window (called screen because there is a window element class)
    pop.screen = pop.create("element", false)\setSize(graphics.getWidth!, graphics.getHeight!)
    print "created \"pop.screen\""

-- creates an element with specified parent (parent can be false or non-existent)
pop.create = (element, parent=pop.screen, ...) ->
    -- if valid parent element (includes default of pop.screen when no parent has been passed)
    if inheritsFromElement parent
        element = pop.elements[element](parent, ...)
        insert parent.child, element
    -- if explicitly no parent
    elseif parent == false
        element = pop.elements[element](false, ...)
    -- else we use pop.screen, and "parent" is actually first argument
    else
        element = pop.elements[element](pop.screen, parent, ...)
        insert pop.screen.child, element

    return element

pop.update = (dt, element=pop.screen) ->
    unless element.excludeUpdate
        if element.update
            element\update dt
        for i = 1, #element.child
            pop.update dt, element.child[i]

pop.draw = (element=pop.screen) ->
    unless element.excludeDraw
        if element.draw
            element\draw!
        for i = 1, #element.child
            pop.draw element.child[i]

pop.mousemoved = (x, y, dx, dy) =>
    if pop.focused and pop.focused.mousemoved
        return pop.focused\mousemoved x, y, dx, dy

    return false

pop.mousepressed = (x, y, button, element) ->
    unless element
        print "mousepressed", x, y, button
        element = pop.screen

    handled = false

    if (x >= element.x) and (x <= element.x + element.w) and (y >= element.y) and (y <= element.y + element.h)
        if element.mousepressed and (not element.excludeDraw)
            handled = element\mousepressed x - element.x, y - element.y, button
        if handled
            pop.focused = element
            pop.events[button] = element
        else
            for i = 1, #element.child
                handled = pop.mousepressed x, y, button, element.child[i]
                if handled
                    break

    return handled

pop.mousereleased = (x, y, button) ->
    print "mousereleased", x, y, button

    clickedHandled = false
    mousereleasedHandled = false

    if element = pop.events[button]
        if element.clicked and (not element.excludeDraw) and (x >= element.x) and (x <= element.x + element.w) and (y >= element.y) and (y <= element.y + element.h)
            if clickedHandled = element\clicked x - element.x, y - element.y, button
                pop.events[button] = nil

        if element.mousereleased and (not element.excludeDraw)
            if mousereleasedHandled = element\mousereleased x - element.x, y - element.y, button
                pop.events[button] = nil

    return clickedHandled, mousereleasedHandled

pop.keypressed = (key) ->
    print "keypressed", key
    return false --TODO event handlers return if they have handled the event!

pop.keyreleased = (key) ->
    print "keyreleased", key
    return false --TODO event handlers return if they have handled the event!

pop.textinput = (text) ->
    print "textinput", text
    return false --TODO event handlers return if they have handled the event!

--TODO rewrite skin system to not rely on knowing internals of elements,
--     instead call functions like setColor and setBackground
-- skins an element (and its children unless depth == true or 0)
--  depth can be an integer for how many levels to go down when skinning
--  defaults to pop.screen and the default skin
pop.skin = (element=pop.screen, skin=pop.skins.default, depth) ->
    if element.background and skin.background
        element.background = skin.background
    if element.color and skin.color
        element.color = skin.color
    if element.font and skin.font
        element.font = skin.font

    unless depth or (depth == 0)
        if depth == tonumber depth
            for i = 1, #element.child
                pop.skin element.child[i], skin, depth - 1
        else
            for i = 1, #element.child
                pop.skin element.child[i], skin, false

pop.debugDraw = (element=pop.screen) ->
    if element.debugDraw
        element\debugDraw!
    else
        graphics.setLineWidth 1
        graphics.setLineColor 0, 0, 0, 100
        graphics.rectangle "fill", element.x, element.y, element.w, element.h
        graphics.setColor 150, 150, 150, 150
        graphics.rectangle "line", element.x, element.y, element.w, element.h
        graphics.setColor 200, 200, 200, 255
        graphics.print ".", element.x, element.y

    for i = 1, #element.child
        pop.debugDraw element.child[i]

pop.load!

return pop