import sys, os, atexit
from pacmd import PacmdError
import pa
try:
    sys.path.append(os.path.dirname(os.path.realpath(__file__)))
    import termio as T
except Exception as e:
    print("Place termio.py and libtermio.so from the github.com/tomsmeding/termio project in this directory")
    print(e)
    sys.exit(1)

__all__ = ["start", "end", "mainloop", "update"]

class Section:
    def __init__(self, title, keys, updater):
        self.items = None
        self.title = title
        self.keys = keys
        self.link_section = None  # sinks for sink-inputs, sources for source-outputs
        self._updater = updater
        self.update()

    def update(self):
        self.items = (self._updater)()

class Selection:
    def __init__(self, section, item):
        self.section = section
        self.item = item

sections = [
    Section("Sink Inputs",    "qvm", lambda: pa.list_sink_inputs()),
    Section("Sinks",          "qvd", lambda: pa.list_sinks()),
    Section("Source Outputs", "qvm", lambda: pa.list_source_outputs()),
    Section("Sources",        "qvd", lambda: pa.list_sources()),
]
sections[0].link_section = sections[1]
sections[2].link_section = sections[3]

sel = Selection(0, 0)
prompt_y = 0  # updated by redraw()

MENU_MAIN, MENU_VOLUME, NUM_MENUS = range(3)
menu = MENU_MAIN

menutext = [0] * NUM_MENUS
menuopts = [0] * NUM_MENUS

menutext[MENU_MAIN] = ""
menuopts[MENU_MAIN] = {
    "q": "(q)uit",
    "v": "(v)olume",
    "d": "(d)efault",
    "m": "(m)ove",
}

menutext[MENU_VOLUME] = "Change volume: <- / -> (alt: 1%)  (m)ute  [q/esc: return]"
menuopts[MENU_VOLUME] = {}


def start():
    T.initscreen()
    atexit.register(T.endscreen)
    T.initkeyboard(False)
    atexit.register(T.endkeyboard)

    redraw()

def end():
    T.endkeyboard()
    atexit.unregister(T.endkeyboard)
    T.endscreen()
    atexit.unregister(T.endscreen)

def mainloop():
    global sel, menu
    while True:
        update()

        sel.item = max(0, min(len(sections[sel.section].items) - 1, sel.item))
        if len(sections[sel.section].items) == 0:
            for i, s in enumerate(sections):
                if len(s.items) != 0:
                    sel.section = i
                    sel.item = 0
                    break
            else:
                sel = Selection(0, 0)

            # We changed the selection, let's return to the main menu
            menu = MENU_MAIN

        redraw()

        key = T.tgetkey()

        if menu != MENU_MAIN and (key == T.KEY_ESC or key == ord("q")):
            menu = MENU_MAIN

        elif menu == MENU_MAIN:
            if key == T.KEY_DOWN:
                sel = selection_down(sel)

            elif key == T.KEY_UP:
                sel = selection_up(sel)

            elif key == ord('q'):
                break

            elif "v" in sections[sel.section].keys and key == ord("v"):
                thing = get_selected()
                kind = thing.kind()
                vol = thing.volume()
                if len(vol) >= 2 and vol[0] != vol[1]:
                    show_message(
                        "Warning: current volume of this " + kind + " is asymmetric!")

                menu = MENU_VOLUME

            elif "d" in sections[sel.section].keys and key == ord("d"):
                wrap_pacmd(lambda: get_selected().set_default())

            elif "m" in sections[sel.section].keys and key == ord("m"):
                thing = get_selected()
                idx = show_prompt(
                        "Enter {} number to link {} {} to"
                            .format(thing.linked_kind(), thing.kind(), thing.index()))

                if idx is None:
                    continue

                try:
                    idx = int(idx)
                except:
                    show_message("Invalid number!")
                    continue

                link_section = sections[sel.section].link_section

                for i in range(len(link_section.items)):
                    if link_section.items[i].index() == idx:
                        wrap_pacmd(lambda: thing.move_to(idx))
                        break
                else:
                    show_message("No {} found with that index!"
                                    .format(thing.linked_kind()))

        elif menu == MENU_VOLUME:
            thing = get_selected()

            incr = 0
            if key == T.KEY_RIGHT:
                incr = 0.05
            elif key == T.KEY_LEFT:
                incr = -0.05
            elif key == T.KEY_ALT + T.KEY_RIGHT:
                incr = 0.01
            elif key == T.KEY_ALT + T.KEY_LEFT:
                incr = -0.01
            elif key == ord("m"):
                thing.set_muted(not thing.muted())
                continue
            else:
                T.bel()
                continue

            vol = thing.volume()
            vol = sum(vol) / len(vol)
            vol = min(1, max(0, vol + incr))
            wrap_pacmd(lambda: thing.set_volume(vol))

        else:
            assert False

def selection_down(sel):
    if sel.item >= len(sections[sel.section].items) - 1:
        if sel.section >= len(sections) - 1:
            T.bel()
            return sel
        else:
            i = sel.section + 1
            while i < len(sections) and len(sections[i].items) == 0:
                i += 1
            if i < len(sections):
                return Selection(i, 0)
            else:
                T.bel()
                return sel
    else:
        return Selection(sel.section, sel.item + 1)

def selection_up(sel):
    if sel.item <= 0:
        if sel.section <= 0:
            T.bel()
            return sel
        else:
            i = sel.section - 1
            while i >= 0 and len(sections[i].items) == 0:
                i -= 1
            if i >= 0:
                return Selection(i, len(sections[i].items) - 1)
            else:
                T.bel()
                return sel
    else:
        return Selection(sel.section, sel.item - 1)

def get_selected():
    return sections[sel.section].items[sel.item]

def wrap_pacmd(lam):
    try:
        lam()
    except pacmd.PacmdError as e:
        show_message("An error occurred:\n" + str(e))

def show_message(msg):
    sz = T.gettermsize()
    T.fillrect(0, prompt_y, sz.w, sz.h - prompt_y, ' ')
    T.moveto(0, prompt_y)
    T.tprint("! " + msg + "\n[press return]")
    T.redraw()

    while True:
        key = T.tgetkey()
        if key == T.KEY_CR or key == T.KEY_LF:
            break

    T.fillrect(0, prompt_y, sz.w, sz.h - prompt_y, ' ')

def show_prompt(msg):
    sz = T.gettermsize()
    T.fillrect(0, prompt_y, sz.w, sz.h - prompt_y, ' ')
    T.moveto(0, prompt_y)
    T.tprint(msg + "\n> ")
    T.redraw()

    line = T.tgetline()

    T.fillrect(0, prompt_y, sz.w, sz.h - prompt_y, ' ')
    return line

# Returns y after end of section on screen
def draw_section(y, items, title, section_selected):
    T.moveto(0, y)
    T.setbold(True)
    T.tprint(title)
    T.setbold(False)
    y += 1

    for i, item in enumerate(items):
        T.moveto(1, y)
        print_item(item, section_selected and sel.item == i)
        y += 1

    return y

def redraw():
    global prompt_y
    if sections[0].items is None:
        update()

    sz = T.gettermsize()
    T.fillrect(0, 0, sz.w, sz.h, ' ')

    T.setstyle(T.Style(9, 9, False, False))

    y = 0
    for i, section in enumerate(sections):
        y = draw_section(y, section.items, section.title, sel.section == i)
        y += 1

    y += 1

    prompt_y = y

    T.moveto(0, y)
    T.tprint(menutext[menu])
    first = True
    for key in sections[sel.section].keys:
        if key not in menuopts[menu]:
            continue
        if first: first = False
        else: T.tprint(" ")
        T.tprint(menuopts[menu][key])

    y += 1

    T.moveto(0, y)
    T.tprint("> ")

    T.redraw()

def print_prefix(thing, selected):
    if selected:
        T.setbold(True)
        T.tprint("> ")
        T.setbold(False)
    else:
        T.tprint("  ")

def fmt_volume(vol):
    res = [str(round(100 * value)) + "%" for value in vol]
    if len(vol) > 2:
        return res[0] + "/" + res[1] + " (? len(vol)==" + str(len(vol)) + ")"
    elif len(vol) == 2:
        if vol[0] == vol[1]:
            return res[0]
        else:
            return res[0] + "/" + res[1]
    elif len(vol) == 1:
        return res[0] + " (mono)"
    else:
        return "? (len(vol)==0)"

def print_volume(thing):
    T.setfg(6)
    T.tprint("(vol: {}{})".format(
        fmt_volume(thing.volume()),
        " (MUTED)" if thing.muted() else ""))
    T.setfg(9)

def print_item(item, selected):
    print_prefix(item, selected)

    T.setfg(3)
    T.tprint("[{}]".format(item.index()))
    T.setfg(9)

    T.tprint(" ")
    T.tprint(item.name())

    if isinstance(item, pa.SinkSource):
        T.tprint("  ")
        print_state(item)

    T.tprint("  ")
    print_volume(item)

    if isinstance(item, pa.SinkSource):
        if item.default():
            T.tprint("  ")
            T.setbold(True)
            T.tprint("[default]")
            T.setbold(False)
    else:
        T.setfg(3)
        T.tprint("  -> " if isinstance(item, pa.SinkInput) else "  <- ")
        T.tprint("[{}]".format(item.linked_index()))
        T.setfg(9)

def print_state(thing):
    T.setfg(6)
    T.tprint("({})".format(thing.state()))
    T.setfg(9)

def update():
    for section in sections:
        section.update()


orig_excepthook = sys.excepthook
def excepthook(exctype, value, traceback):
    T.endkeyboard()
    T.endscreen()
    orig_excepthook(exctype, value, traceback)

sys.excepthook = excepthook