from point2 import Point

bg_color         = 'black'
selected_color   = 'magenta'
unselected_color = 'yellow'

def find_ranges(s, w, start=None, end=None):
    if not w.buffer.lines:
        return []

    if start is None:
        (x, y) = (0, 0)
    else:
        (x, y) = start.xy()
    if end is None:
        (x2, y2) = (len(w.buffer.lines[-1]) - 1, len(w.buffer.lines) - 1)
    else:
        (x2, y2) = end.xy()

    ranges = []
    while y <= y2:
        if y == y2:
            limit = x2
        else:
            limit = len(w.buffer.lines[y]) - 1
        while x <= limit:
            try:
                i = w.buffer.lines[y].index(s, x)
            except ValueError:
                break
            x = i + len(s)
            ranges.append([Point(i, y), Point(x, y), bg_color, unselected_color])
        x = 0
        y += 1
    return ranges

def find(s, w, move=False, direction='next', start=None, end=None):
    app     = w.application
    c       = w.logical_cursor()
    newc    = None
    ranges  = find_ranges(s, w, start, end)
    indices = range(0, len(ranges))
    (x, y) = c.xy()
    if move:
        offset = 1
    else:
        offset = 0
    if direction == 'next':
        limit = Point(x - 1 + offset, y)
    else:
        limit  = Point(x + len(s) + 1 - offset, y)
        indices.reverse()
    for i in indices:
        if ((direction == 'next' and ranges[i][0] > limit) or
            (direction != 'next' and ranges[i][1] < limit)):
            ranges[i][3] = selected_color
            newc = (ranges[i][0], ranges[i][1])
            break
    if ranges and not newc:
        return None
    app.clear_highlighted_ranges()
    if newc:
        w.goto(newc[0])
    for (p1, p2, fg, bg) in ranges:
        if p1 < w.first:
            continue
        elif p2 > w.last:
            break
        app.add_highlighted_range(w, p1, p2, fg, bg)
    return newc

def find_previous(s, w, move=False, start=None, end=None):
    return find(s, w, move, 'previous', start, end)

def find_next(s, w, move=False, start=None, end=None):
    return find(s, w, move, 'next', start, end)