local function imLoadImage(fname)
    local f = im.FileOpen(fname)
    local r = f:LoadImage()
    f:Close()
    return r
end

dalosp.struct = {
    images = {
        up = imLoadImage "12-em-up.tga",
        down = imLoadImage "12-em-down.tga",
        cross = imLoadImage "12-em-cross.tga",
        plus = imLoadImage "12-em-plus.tga",
    },
    
    types = {
        "int8",
        "uint8",
        "int16",
        "uint16",
        "int32",
        "uint32",
        "int64",
        "uint64",
        "float",
        "double",
        "nascii",
        "asciiz",
    },
    
    rtypes = {
        int8 = 1,
        uint8 = 2,
        int16 = 3,
        uint16 = 4,
        int32 = 5,
        uint32 = 6,
        int64 = 7,
        uint64 = 8,
        float = 9,
        double = 10,
        nascii = 11,
        asciiz = 12,
    },
    
    typessizes = {
        1, 1, 2, 2, 4, 4, 8, 8, 4, 8, 1, -1,
    },
    
    get_settings = function (self)
    end,
    
    configure = function (self)
        self.cfg_dlg:popup()
    end,
    
    activate = function (self)
        self.actv_dlg:show()
    end,
    
    input_change = function (self)
    end,
    
    offset = function (self, lin)
        local cache = self.extra.cache
        return cache[lin]
    end,
    
    cacheoffset = function (self)
        local entries = self.extra.entries
        self.extra.cache = {}
        local cache = self.extra.cache
        local offset = 0
        local got_var = false
        local ssize
        local vsize
        
        for i, v in ipairs(entries) do
            ssize = dalosp.struct.typessizes[v.type]
            vsize = ssize == -1 or type(v.size) ~= "number"
            if vsize then got_var = true end
            if got_var then
                cache[i] = -1
            else
                cache[i] = offset
            end
            if not vsize then offset = offset + ssize * v.size end
        end
        self.extra.size = offset
        if self.cfg_dlg then
            self.cfg_dlg.mx.redraw = "C10"
            self.cfg_dlg.lsize.title = offset
        end
    end,
    
    isunique = function (self, name)
        for _, v in ipairs(self.extra.entries) do
            if name == v.name then return false end
        end
        return true
    end,
    
    getunique = function (self, lin)
        local newname = "Field" .. lin
        local base_newname = newname
        local i = 1
        while not self:isunique(newname) do
            newname = base_newname .. "." .. i
            i = i + 1
        end
        return newname
    end,
    
    insert_line = function (self, lin)
        if not lin then lin = (#self.extra.entries + 1) end
        local name = self:getunique(lin)
        table.insert(self.extra.entries, lin, { name = name, type = 1, size = 1 })
        self:cacheoffset()
        local mx = self.cfg_dlg.mx
        mx.numlin = mx.numlin + 1
        mx.numlin_visible = mx.numlin_visible + 1
    end,
    
    remove_line = function (self, lin)
        table.remove(self.extra.entries, lin)
        self:cacheoffset()
        local mx = self.cfg_dlg.mx
        mx.numlin = mx.numlin - 1
        mx.numlin_visible = mx.numlin_visible - 1
    end,
    
    line_up = function (self, lin)
        if lin == 1 then return iup.DEFAULT end
        local entries = self.extra.entries
        local old_lin = entries[lin]
        table.remove(entries, lin)
        table.insert(entries, lin - 1, old_lin)
        self:cacheoffset()
        local mx = self.cfg_dlg.mx
        mx.redraw = "All"
    end,
    
    line_down = function (self, lin)
        local entries = self.extra.entries
        if lin == #entries then return iup.DEFAULT end
        local old_lin = entries[lin]
        table.remove(entries, lin)
        table.insert(entries, lin + 1, old_lin)
        self:cacheoffset()
        local mx = self.cfg_dlg.mx
        mx.redraw = "All"
    end,
    
    cfg_draw_cb = function (self, lin, col, x1, x2, y1, y2, cv)
        if col == 1 then
            dalosp.struct.images.plus:cdCanvasPutImageRect(cv, x1 + 3, y2 + 5, 12, 12, 0, 12, 0, 12)
            return iup.DEFAULT
        elseif col == 2 and lin ~= 0 then
            dalosp.struct.images.cross:cdCanvasPutImageRect(cv, x1 + 3, y2 + 5, 12, 12, 0, 12, 0, 12)
            return iup.DEFAULT
        elseif col == 3 and lin ~= 0 and lin ~= 1 then
            dalosp.struct.images.up:cdCanvasPutImageRect(cv, x1 + 3, y2 + 5, 12, 12, 0, 12, 0, 12)
            return iup.DEFAULT
        elseif col == 4 and lin ~= 0 and lin ~= #self.struct.extra.entries then
            dalosp.struct.images.down:cdCanvasPutImageRect(cv, x1 + 3, y2 + 5, 12, 12, 0, 12, 0, 12)
            return iup.DEFAULT
        end
        
        return iup.IGNORE
    end,
    
    cfg_click_cb = function (self, lin, col, status)
        if col == 1 and lin == 0 then return self.struct:insert_line() end
        if lin == 0 then return iup.DEFAULT end
        
        if col == 1 then
            self.struct:insert_line(lin)
        elseif col == 2 then
            self.struct:remove_line(lin)
        elseif col == 3 then
            self.struct:line_up(lin)
        elseif col == 4 then
            self.struct:line_down(lin)
        end
    end,
    
    cfg_value_cb = function (self, lin, col)
        if lin == 0 then
            if col == 5 then
                return "Name"
            elseif col == 6 then
                return "Type"
            elseif col == 7 then
                return "Size"
            elseif col == 8 then
                return "Enum"
            elseif col == 9 then
                return "Value Check"
            elseif col == 10 then
                return "Offset"
            end
            return ""
        end
        
        local entries = self.struct.extra.entries
        
        if col == 5 then
            return entries[lin].name
        elseif col == 6 then
            return dalosp.struct.types[entries[lin].type]
        elseif col == 7 then
            return entries[lin].size
        elseif col == 10 then
            return self.struct:offset(lin)
        end
        
        return ""
    end,
    
    cfg_value_edit_cb = function (self, lin, col, newval)
        local entries = self.struct.extra.entries
        
        if col == 5 then
            entries[lin].name = newval
        elseif col == 6 then
            entries[lin].type = dalosp.struct.rtypes[newval]
            self.struct:cacheoffset()
        elseif col == 7 then
            local nnewval = tonumber(newval)
            if nnewval then newval = nnewval end
            entries[lin].size = nnewval
            self.struct:cacheoffset()
        elseif col == 8 then
            -- enum
        elseif col == 9 then
            -- value check
        end
    end,

    cfg_dropcheck_cb = function (self, lin, col)
        return col == 6 and iup.DEFAULT or iup.IGNORE
    end,
    
    cfg_edition_cb = function (self, lin, col, mode, update)
        if mode == 1 then
            return (col >= 5 and col <= 7) and iup.DEFAULT or iup.IGNORE
        else
            if update == 0 then return iup.DEFAULT end
            if col == 5 then
                -- lookup duplicates in names
            elseif col == 6 then
                -- do a check on the dropdown ? I don't think so
            elseif col == 7 then
                -- do a check on the size; can be the name of another field
            elseif col == 8 then
                -- enum
            elseif col == 9 then
                -- value check
            end
            return iup.DEFAULT
        end
    end,
    
    cfg_drop_cb = function (self, drop, lin, col)
        if col ~= 6 then return iup.IGNORE end
        
        for i, v in ipairs(dalosp.struct.types) do
            drop[i] = v
        end
        drop.value = self.previousvalue
        drop.visible_items = 15
        
        return iup.DEFAULT
    end,
    
    create = function (d, tab, settings)
        tab.ninputs = 1
        tab.noutputs = 1
        tab.otype = dalos.objtype.LUA_VIEWER
        tab.configure = dalosp.struct.configure
        tab.activate = dalosp.struct.activate
        tab.input_change = dalosp.struct.input_change
        tab.get_settings = dalosp.struct.get_settings
        tab.draw = function (self, cv, x, y, w, h)
            dalosp.object.default_draw(self, cv, x, y, w, h)
        end
        tab.default_name = "Struct"
        tab.ntype = "Struct"

        local extra = { }
        if not settings then settings = {} end
        extra.entries = settings.entries or {}
        
        local obj = dalos.object(d, tab, extra)
        
        obj.insert_line = dalosp.struct.insert_line
        obj.remove_line = dalosp.struct.remove_line
        obj.line_up = dalosp.struct.line_up
        obj.line_down = dalosp.struct.line_down
        obj.offset = dalosp.struct.offset
        obj.cacheoffset = dalosp.struct.cacheoffset
        obj.isunique = dalosp.struct.isunique
        obj.getunique = dalosp.struct.getunique
        
        obj:cacheoffset()
        
        local cmx = iup.matrix {
            numcol = 10,
            numcol_visible = 10,
            usetitlesize = "Yes",
            rasterwidth1 = 12,
            rasterwidth2 = 12,
            rasterwidth3 = 12,
            rasterwidth4 = 12,
            rasterwidth5 = 120,
            rasterwidth6 = 80,
            rasterwidth7 = 80,
            rasterwidth8 = 80,
            rasterwidth9 = 120,
            rasterwidth10 = 40,
            resizematrix = "Yes",
            readonly = "No",
            draw_cb = dalosp.struct.cfg_draw_cb,
            value_cb = dalosp.struct.cfg_value_cb,
            value_edit_cb = dalosp.struct.cfg_value_edit_cb,
            dropcheck_cb = dalosp.struct.cfg_dropcheck_cb,
            drop_cb = dalosp.struct.cfg_drop_cb,
            edition_cb = dalosp.struct.cfg_edition_cb,
            click_cb = dalosp.struct.cfg_click_cb,
            struct = obj,
        }
        local amx = iup.matrix {
            numcol = 2,
            numcol_visible = 2,
            usetitlesize = "Yes",
            rasterwidth1 = 120,
            rasterwidth2 = 120,
            struct = obj,
        }
        local lsize = iup.label { title = "0", expand = "Horizontal", }
        
        obj.cfg_dlg = iup.dialog {
            iup.vbox {
                iup.hbox {
                    iup.label { title = "Struct size: " },
                    lsize,
                },
                cmx,
                iup.hbox {
                    iup.fill {},
                    iup.button {
                        title = "Ok",
                        action = function (self) return iup.CLOSE end
                    },
                    iup.fill {},
                },
            },
            
            size = "450x220",
            mx = cmx,
            lsize = lsize
        }
        
        obj.actv_dlg = iup.dialog {
            amx,
        }
        
        return obj
    end,
}

dalos.struct = dalosp.struct.create
dalos:register_obj("Struct", dalos.struct, "Programmable")