// files.zap - a file browser app for ZeaxOS.
// Click a folder to open it, a file to select it; Ctrl+Esc quits.

// #engine

fn join(a, b) {
  if a == "/" { return "/" + b }
  if ends_with(a, "/") { return a + b }
  return a + "/" + b
}

fn parent(p) {
  if p == "/" { return "/" }
  let q = p
  if ends_with(q, "/") { q = substr(q, 0, len(q) - 1) }
  let i = len(q) - 1
  while i > 0 && substr(q, i, 1) != "/" { i = i - 1 }
  if i <= 0 { return "/" }
  return substr(q, 0, i)
}

fn size_text(n) {
  if n < 1024 { return str(n) + " B" }
  return str(n / 1024) + "." + str(n % 1024 * 10 / 1024) + " KB"
}

// #main

let W = gfx_width()
let H = gfx_height()
let TOP = 16
let BG = rgb(10, 14, 18)
let FG = rgb(230, 237, 243)
let MUTED = rgb(122, 138, 154)
let ACCENT = rgb(0, 229, 255)
let GREEN = rgb(0, 255, 102)
let LINE = rgb(42, 58, 74)
let QH = "Ctrl+Esc quits"

let M = 14
let TB = TOP + 44
let TH = 30
let PATHY = TB + 44
let LISTX = M
let LISTY = PATHY + 28
let LISTW = W - 2 * M
let ROWH = 26
let BOT = H - 26
let ROWS = (BOT - LISTY - 8) / ROWH

let cwd = "/"
let names = []
let dirs = []
let top = 0
let sel = -1
let info = "ready"
let running = true

fn inr(x, y, rx, ry, rw, rh) {
return x >= rx && x < rx + rw && y >= ry && y < ry + rh
}

fn reload() {
let raw = sort(list_dir(cwd))
let tn = []
let td = []
for n in raw {
push(tn, n)
push(td, is_dir(join(cwd, n)))
}
names = []
dirs = []
let pass = 0
while pass < 2 {
let i = 0
while i < len(tn) {
if td[i] == (pass == 0) {
push(names, tn[i])
push(dirs, td[i])
}
i = i + 1
}
pass = pass + 1
}
top = 0
sel = -1
info = str(len(names)) + " items"
}

fn hit(x, y) {
if inr(x, y, M, TB, 64, TH) { return 0 }
if inr(x, y, M + 76, TB, 84, TH) { return 1 }
if inr(x, y, W - M - 176, TB, 76, TH) { return 2 }
if inr(x, y, W - M - 90, TB, 76, TH) { return 3 }
if x >= LISTX && x < LISTX + LISTW && y >= LISTY && y < LISTY + ROWS * ROWH {
let r = (y - LISTY) / ROWH
if r < ROWS && top + r < len(names) { return 100 + r }
}
return -1
}

fn on_click(id) {
if id == 0 { cwd = parent(cwd)
reload()
return }
if id == 1 { running = false
return }
if id == 2 { top = top - ROWS
if top < 0 { top = 0 }
return }
if id == 3 { top = top + ROWS
return }
let idx = top + id - 100
if idx < 0 || idx >= len(names) { return }
sel = idx
if dirs[idx] {
cwd = join(cwd, names[idx])
reload()
} else {
info = names[idx] + "   " + size_text(file_size(join(cwd, names[idx])))
}
}

fn tb(x, w, textstr, hid, id) {
let hot = hid == id
rect(x, TB, w, TH, hot ? ACCENT : LINE)
text(x + (w - text_w(textstr)) / 2, TB + (TH - 16) / 2, textstr, hot ? ACCENT : FG)
}

fn render(hid) {
fill_rect(0, TOP, W, H - TOP, BG)
text(8, TOP + 4, "Files", GREEN)
text(W - text_w(QH) - 8, TOP + 4, QH, MUTED)
fill_rect(0, TOP + 26, W, 2, LINE)
tb(M, 64, "Up", hid, 0)
tb(M + 76, 84, "Quit", hid, 1)
tb(W - M - 176, 76, "Prev", hid, 2)
tb(W - M - 90, 76, "Next", hid, 3)
text(M, PATHY, cwd, ACCENT)
let i = 0
while i < ROWS {
let idx = top + i
if idx < len(names) {
let ry = LISTY + i * ROWH
let cur = idx == sel
let hot = hid == 100 + i
let col = cur ? GREEN : (hot ? ACCENT : FG)
rect(LISTX, ry, LISTW, ROWH - 4, cur ? GREEN : (hot ? ACCENT : LINE))
text(LISTX + 10, ry + 3, names[idx], col)
if dirs[idx] { text(LISTX + 10 + text_w(names[idx]), ry + 3, "/", col) }
}
i = i + 1
}
fill_rect(0, BOT, W, 2, LINE)
text(8, BOT + 4, info, MUTED)
}

reload()
let hid = -2
let pmx = -1
let pmy = -1
let pmb = 0
cursor_show()
while running {
let k = key()
if k == 269 { break }
let mx = mouse_x()
let my = mouse_y()
let mb = mouse_buttons()
let moved = mx != pmx || my != pmy || mb != pmb
let click = mb % 2 != 0 && pmb % 2 == 0
pmx = mx
pmy = my
pmb = mb
let id = hit(mx, my)
if click && id >= 0 { on_click(id) }
if id != hid || click {
cursor_hide()
render(id)
cursor_move(mx, my)
cursor_show()
hid = id
} else if moved {
cursor_move(mx, my)
}
sleep(5)
}
cursor_hide()