//% shim=pxt::listPrjFiles
function getPrjs() {
    let programs = [
        "pxt",
        "my amazing robot",
    ]
    for (let i = 1; i < 6; ++i)
        programs.push("Untitled-" + i)
    return programs
}

//% shim=pxt::deletePrjFile
function delPrj(fn: string) {
    return
}

const programs = getPrjs()
    .filter(s => s.substr(s.length - 4, 4) == ".rbf")
    .map(s => s.substr(0, s.length - 4))
    .filter(s => s != "File_manager")

programs.push("")
programs.push("Cancel")
programs.push("Delete 0 files")

let todel: boolean[] = []
let scrollTop = 0
let cursor = 0
let confirm = false
function showMenu() {
    if (cursor < scrollTop + 2)
        scrollTop = cursor - 2
    else if (cursor > scrollTop + 11)
        scrollTop = cursor - 11
    if (scrollTop < 0)
        scrollTop = 0
    let num = 0
    for (let i = 0; i < todel.length; ++i)
        if (todel[i]) num++
    programs[programs.length - 1] =
        confirm ? "Enter to confirm" : "Delete " + num + " file(s)"

    brick.clearScreen()

    const h = brick.lineHeight()
    for (let i = 0; i < 13; ++i) {
        const y = i * h
        const idx = scrollTop + i
        const fg = idx == cursor ? 0 : 1
        const bg = idx == cursor ? 1 : 0
        // screen.fillRect(0, y, screen.width, h, bg);
        let text = (idx == cursor ? ">" : " ")
            + (todel[idx] ? "*" : " ")
            + " "
            + (programs[scrollTop + i] || "")
        screen.print(text, 0, y, fg, brick.font);
    }
}
function move(d: number) {
    confirm = false
    const nc = cursor + d
    if (0 <= nc && nc < programs.length)
        cursor = nc
    showMenu()
}
brick.buttonDown.onEvent(ButtonEvent.Pressed, () => move(1))
brick.buttonUp.onEvent(ButtonEvent.Pressed, () => move(-1))
brick.buttonEnter.onEvent(ButtonEvent.Pressed, function () {
    if (cursor < programs.length - 3) {
        todel[cursor] = !todel[cursor]
        move(1)
    } else if (cursor == programs.length - 3) {
        // nothing
    } else if (cursor == programs.length - 2) {
        control.reset()
    } else if (cursor == programs.length - 1) {
        if (todel.every(x => !x))
            return
        if (confirm) {
            brick.clearScreen()
            brick.showString("deleting...", 6)
            for (let i = 0; i < todel.length; ++i) {
                if (todel[i]) {
                    delPrj(programs[i] + ".elf")
                    delPrj(programs[i] + ".rbf")
                }
            }
            pause(1000)
            control.reset()
        } else {
            confirm = true
            showMenu()
        }
    }
})
showMenu()