local separators = " ()[],-+*/=<>"

local function split_by_last_separator(s)
    for i = #s, 1, -1 do
        local c = s:sub(i, i)
        if separators:find(c, 1, true) then
            if i == #s then
                -- Separador al final
                return s, ""
            end
            -- Separador en medio
            return s:sub(1, i), s:sub(i + 1)
        end
    end
    -- Sin separadores
    return "", s
end

local function split_by_last_dot(s)
    local last = s:match(".*()%.")  -- devuelve la posición DESPUÉS del último punto

    if not last then
        -- No hay puntos: primera parte = cadena completa, segunda = ""
        return "", s
    end

    -- Si el punto está al final, la segunda parte es ""
    if last > #s then
        return s, ""
    end

    -- Primera parte incluye el punto
    local first = s:sub(1, last - 1)
    local second = s:sub(last+1)

    return first, second
end

function get_by_path(path)
    local current = _G

    for segment in path:gmatch("[^%.]+") do
        if type(current) ~= "table" then
            return nil
        end
        current = current[segment]
        if current == nil then
            --print("get_by_path: " ..segment.." es nil")
            return nil
        end
    end

    --print("get_by_path: ok")
    return current
end

function entries_starting_with(s, t)
    if not t then return nil end
    local result = {}
    for k, v in pairs(t) do
        if type(k) == "string" and k:sub(1, #s) == s then
            result[#result+1] = k
        end
    end
    return result
end

console = {
    command = "",
    history = {},
    history_pos = 0,
    cursor = 50,
    autocomplete_list = {},
    autocomplete_prefix = "",
    autocomplete_index = 1,

    enable = function()
        app.push(console.update)
        console.command = ""
    end,

    update = function()
        surf.target(0)
        draw.rrectf(0, 92, 160, 108, 4, 1)
        draw.rrect(0, 92, 160, 108, 4, 13)
        draw.text(">", 2, 96, 13)
        draw.text(console.command, 6, 96, 13)

        if console.autocomplete_list and #console.autocomplete_list>0 then
            --local num = math.min(5, #console.autocomplete_list)
            --local base_y = 92-num*7
            --draw.rectf(3+#console.command*4, base_y, 80, num*7, 1)
            --draw.rect(3+#console.command*4, base_y, 80, num*7, 13)
            --for i=1,num do
            --    draw.text(console.autocomplete_list[i], 6+#console.command*4, base_y+i*7, 13)
            --end

            local sufix = console.autocomplete_list[console.autocomplete_index]:sub(#console.autocomplete_prefix+1)
            draw.text(sufix, 6+#console.command*4, 96, 6)
        end

        if console.cursor > 24 then
            draw.text("_", 6+#console.command*4, 96, 13)
        end
        console.cursor = console.cursor - 1
        if console.cursor == 0 then console.cursor = 50 end

        if key.press(key.ESCAPE) then
            app.pop()
            return
        end

        local should_update = false

        if #console.history>0 then
            if key.press(key.UP) and console.history_pos > 1 then
                console.history_pos = console.history_pos - 1
                console.command = console.history[console.history_pos]
                should_update = true
            elseif key.press(key.DOWN) and console.history_pos < #console.history then
                console.history_pos = console.history_pos + 1
                console.command = console.history[console.history_pos]
                should_update = true
            end
        end

        local k = key.press()
        if k ~= key.UNKNOWN then
            should_update = true
            if k >= key.A and k <= key.Z then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. string.char(k+61)
                else
                    console.command = console.command .. string.char(k+93)
                end
            elseif k == key.N0 then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '='
                elseif key.down(key.RALT) then
                    console.command = console.command .. '}'
                else
                    console.command = console.command .. '0'
                end
            elseif k == key.N1 then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '!'
                elseif key.down(key.RALT) then
                    console.command = console.command .. '|'
                else
                    console.command = console.command .. '1'
                end
            elseif k == key.N2 then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '"'
                elseif key.down(key.RALT) then
                    console.command = console.command .. '@'
                else
                    console.command = console.command .. '2'
                end
            elseif k == key.N3 then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '·'
                elseif key.down(key.RALT) then
                    console.command = console.command .. '#'
                else
                    console.command = console.command .. '3'
                end
            elseif k == key.N4 then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '$'
                elseif key.down(key.RALT) then
                    console.command = console.command .. '~'
                else
                    console.command = console.command .. '4'
                end
            elseif k == key.N5 then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '%'
                elseif key.down(key.RALT) then
                    console.command = console.command .. ' '
                else
                    console.command = console.command .. '5'
                end
            elseif k == key.N6 then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '&'
                elseif key.down(key.RALT) then
                    console.command = console.command .. ' '
                else
                    console.command = console.command .. '6'
                end
            elseif k == key.N7 then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '/'
                elseif key.down(key.RALT) then
                    console.command = console.command .. ' '
                else
                    console.command = console.command .. '7'
                end
            elseif k == key.N8 then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '('
                elseif key.down(key.RALT) then
                    console.command = console.command .. ' '
                else
                    console.command = console.command .. '8'
                end
            elseif k == key.N9 then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. ')'
                elseif key.down(key.RALT) then
                    console.command = console.command .. ' '
                else
                    console.command = console.command .. '9'
                end

            elseif k == key.PERIOD then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. ':'
                else
                    console.command = console.command .. '.'
                end

            elseif k == key.COMMA then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. ';'
                else
                    console.command = console.command .. ','
                end

            elseif k == key.GRAVE then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. ' '
                elseif key.down(key.RALT) then
                    console.command = console.command .. '\\'
                else
                    console.command = console.command .. ' '
                end

            elseif k == key.EQUALS then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '¿'
                else
                    console.command = console.command .. '¡'
                end

            elseif k == key.SLASH then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '_'
                elseif key.down(key.RALT) then
                    console.command = console.command .. ' '
                else
                    console.command = console.command .. '-'
                end

            elseif k == key.APOSTROPHE then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '"'
                elseif key.down(key.RALT) then
                    console.command = console.command .. '{'
                else
                    console.command = console.command .. '\''
                end

            elseif k == key.SEMICOLON then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. 'Ñ'
                elseif key.down(key.RALT) then
                    console.command = console.command .. ' '
                else
                    console.command = console.command .. 'ñ'
                end

            elseif k == key.BACKSLASH then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. 'Ç'
                elseif key.down(key.RALT) then
                    console.command = console.command .. '}'
                else
                    console.command = console.command .. 'ç'
                end

            elseif k == key.RIGHTBRACKET then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '*'
                elseif key.down(key.RALT) then
                    console.command = console.command .. ']'
                else
                    console.command = console.command .. '+'
                end

            elseif k == key.LEFTBRACKET then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '^'
                elseif key.down(key.RALT) then
                    console.command = console.command .. '['
                else
                    console.command = console.command .. '`'
                end

            elseif k == key.NONUSBACKSLASH then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '>'
                elseif key.down(key.RALT) then
                    console.command = console.command .. ' '
                else
                    console.command = console.command .. '<'
                end

            elseif k == key.MINUS then
                if key.down(key.LSHIFT) or key.down(key.RSHIFT) then
                    console.command = console.command .. '?'
                else
                    console.command = console.command .. '\''
                end

            elseif k == key.SPACE then
                console.command = console.command .. ' '
            elseif k == key.BACKSPACE then
                console.command = console.command:sub(1, #console.command - 1)
            
            elseif k == key.TAB then
                local sufix = console.autocomplete_list[console.autocomplete_index]:sub(#console.autocomplete_prefix+1)
                console.command = console.command .. sufix

            elseif k == key.RETURN then
                table.insert(console.history, console.command)
                console.history_pos = #console.history+1
                local f,err = load(console.command)
                if not f then
                    print("Error al compilar:", err)
                else
                    print(f())
                    app.pop()
                end
            end

        end

        if should_update then
            local a, b = split_by_last_separator(console.command)
            if b ~= "" then
                local ba, bb = split_by_last_dot(b)
                console.autocomplete_prefix = bb
                if ba ~= "" then
                    console.autocomplete_list = entries_starting_with(bb, get_by_path(ba))
                    --print(bb..":"..ba)
                    --print(#console.autocomplete_list)
                else
                    console.autocomplete_list = entries_starting_with(bb, _G)
                    --print(bb..":".."golbal")
                    --print(#console.autocomplete_list)
                end
            else
                console.autocomplete_prefix = ""
                console.autocomplete_list = entries_starting_with("", _G)
                --print("<buit>"..":".."golbal")
                --print(#console.autocomplete_list)
            end
        end
    end,

}