# -*- coding: utf-8 -*-
from __future__ import unicode_literals, absolute_import

"""Photo album models."""

import os
from flask import g
import time
import requests
from PIL import Image
import hashlib
import random

from rophako.settings import Config
import rophako.jsondb as JsonDB
from rophako.utils import sanitize_name, remote_addr
from rophako.log import logger

# Maps the friendly names of photo sizes with their pixel values from config.
PHOTO_SCALES = dict(
    large=int(Config.photo.width_large),
    thumb=int(Config.photo.width_thumb),
    avatar=int(Config.photo.width_avatar),
)


def list_albums():
    """Retrieve a sorted list of the photo albums."""
    index = get_index()
    result = []

    # Missing settings?
    if not "settings" in index:
        index["settings"] = dict()

    for album in index["album-order"]:
        if not album in index["settings"]:
            # Need to initialize its settings.
            index["settings"][album] = dict(
                format="classic",
                description="",
            )
            write_index(index)

        cover = index["covers"][album]
        pic = index["albums"][album][cover]["thumb"]
        result.append(dict(
            name=album,
            format=index["settings"][album]["format"],
            description=index["settings"][album]["description"],
            cover=pic,
            data=index["albums"][album],
        ))

    return result


def get_album(name):
    """Get details about an album."""
    index = get_index()

    if not name in index["albums"]:
        return None

    album = index["albums"][name]
    cover = index["covers"][name]

    return dict(
        name=name,
        format=index["settings"][name]["format"],
        description=index["settings"][name]["description"],
        cover=album[cover]["thumb"],
    )


def rename_album(old_name, new_name):
    """Rename an existing photo album.

    Returns True on success, False if the new name conflicts with another
    album's name."""
    old_name = sanitize_name(old_name)
    new_name = sanitize_name(new_name)
    index = get_index()

    # New name is unique?
    if new_name in index["albums"]:
        logger.error("Can't rename album: new name already exists!")
        return False

    def transfer_key(obj, old_key, new_key):
        # Reusable function to do a simple move on a dict key.
        obj[new_key] = obj[old_key]
        del obj[old_key]

    # Simple moves.
    transfer_key(index["albums"], old_name, new_name)
    transfer_key(index["covers"], old_name, new_name)
    transfer_key(index["photo-order"], old_name, new_name)
    transfer_key(index["settings"], old_name, new_name)

    # Update the photo -> album maps.
    for photo in index["map"]:
        if index["map"][photo] == old_name:
            index["map"][photo] = new_name

    # Fix the album ordering.
    new_order = list()
    for name in index["album-order"]:
        if name == old_name:
            name = new_name
        new_order.append(name)
    index["album-order"] = new_order

    # And save.
    write_index(index)
    return True


def list_photos(album):
    """List the photos in an album."""
    album = sanitize_name(album)
    index = get_index()

    if not album in index["albums"]:
        return None

    result = []
    for key in index["photo-order"][album]:
        data = index["albums"][album][key]
        result.append(dict(
            key=key,
            data=data,
        ))

    return result


def photo_exists(key):
    """Query whether a photo exists in the album."""
    index = get_index()
    return key in index["map"]


def get_photo(key):
    """Look up a photo by key. Returns None if not found."""
    index = get_index()
    photo = None
    if key in index["map"]:
        album = index["map"][key]
        if album in index["albums"] and key in index["albums"][album]:
            photo = index["albums"][album][key]
        else:
            # The map is wrong!
            logger.error("Photo album map is wrong; key {} not found in album {}!".format(key, album))
            del index["map"][key]
            write_index(index)

    if not photo:
        return None

    # Inject additional information about the photo:
    # What position it's at in the album, how many photos total, and the photo
    # IDs of its siblings.
    siblings = index["photo-order"][album]
    i = 0
    for pid in siblings:
        if pid == key:
            # We found us! Find the siblings.
            sprev, snext = None, None
            if i == 0:
                # We're the first photo. So previous is the last!
                sprev = siblings[-1]
                if len(siblings) > i+1:
                    snext = siblings[i+1]
                else:
                    snext = key
            elif i == len(siblings)-1:
                # We're the last. So next is first!
                sprev = siblings[i-1]
                snext = siblings[0]
            else:
                # Right in the middle.
                sprev = siblings[i-1]
                snext = siblings[i+1]

            # Inject.
            photo["album"] = album
            photo["position"] = i+1
            photo["siblings"] = len(siblings)
            photo["previous"] = sprev
            photo["next"] = snext
        i += 1

    return photo


def get_image_dimensions(pic):
    """Use PIL to get the image's true dimensions."""
    filename = os.path.join(Config.photo.root_private, pic["large"])
    img = Image.open(filename)
    return img.size


# def update_photo(album, key, data):
#     """Update photo meta-data in the album."""
#     index = get_index()

#     if not album in index["albums"]:
#         index["albums"][album] = {}
#     if not key in index["albums"][album]:
#         index["albums"][album][key] = {}

#     # Update!
#     index["albums"][album][key].update(data)
#     write_index(index)


def crop_photo(key, x, y, length):
    """Change the crop coordinates of a photo and re-crop it."""
    index = get_index()
    if not key in index["map"]:
        raise Exception("Can't crop photo: doesn't exist!")

    album = index["map"][key]

    # Sanity check.
    if not album in index["albums"]:
        raise Exception("Can't find photo in album!")

    logger.debug("Recropping photo {}".format(key))

    # Delete all the images except the large one.
    for size in ["thumb", "avatar"]:
        pic = index["albums"][album][key][size]
        logger.debug("Delete {} size: {}".format(size, pic))
        os.unlink(os.path.join(Config.photo.root_private, pic))

    # Regenerate all the thumbnails.
    large = index["albums"][album][key]["large"]
    source = os.path.join(Config.photo.root_private, large)
    for size in ["thumb", "avatar"]:
        pic = resize_photo(source, size, crop=dict(
            x=x,
            y=y,
            length=length,
        ))
        index["albums"][album][key][size] = pic

    # Save changes.
    write_index(index)


def set_album_cover(album, key):
    """Change the album's cover photo."""
    album = sanitize_name(album)
    index = get_index()
    logger.info("Changing album cover for {} to {}".format(album, key))
    if album in index["albums"] and key in index["albums"][album]:
        index["covers"][album] = key
        write_index(index)
        return
    logger.error("Failed to change album index! Album or photo not found.")


def edit_photo(key, data):
    """Update a photo's data."""
    index = get_index()
    if not key in index["map"]:
        logger.warning("Tried to delete photo {} but it wasn't found?".format(key))
        return

    album = index["map"][key]

    logger.info("Updating data for the photo {} from album {}".format(key, album))
    index["albums"][album][key].update(data)

    write_index(index)


def edit_album(album, data):
    """Update an album's settings (description, format, etc.)"""
    album = sanitize_name(album)
    index = get_index()
    if not album in index["albums"]:
        logger.error("Failed to edit album: not found!")
        return

    index["settings"][album].update(data)
    write_index(index)


def rotate_photo(key, rotate):
    """Rotate a photo 90 degrees to the left or right."""
    photo = get_photo(key)
    if not photo: return

    # Degrees to rotate.
    degrees = None
    if rotate == "left":
        degrees = 90
    elif rotate == "right":
        degrees = -90
    else:
        degrees = 180

    new_names = dict()
    for size in ["large", "thumb", "avatar"]:
        fname = os.path.join(Config.photo.root_private, photo[size])
        logger.info("Rotating image {} by {} degrees.".format(fname, degrees))

        # Give it a new name.
        filetype = fname.split(".")[-1]
        outfile = random_name(filetype)
        new_names[size] = outfile

        img = Image.open(fname)
        img = img.rotate(degrees)
        img.save(os.path.join(Config.photo.root_private, outfile))

        # Delete the old name.
        os.unlink(fname)

    # Save the new image names.
    edit_photo(key, new_names)


def delete_photo(key):
    """Delete a photo."""
    index = get_index()
    if not key in index["map"]:
        logger.warning("Tried to delete photo {} but it wasn't found?".format(key))
        return

    album = index["map"][key]

    logger.info("Completely deleting the photo {} from album {}".format(key, album))
    photo = index["albums"][album][key]

    # Delete all the images.
    for size in ["large", "thumb", "avatar"]:
        logger.info("Delete: {}".format(photo[size]))
        fname = os.path.join(Config.photo.root_private, photo[size])
        if os.path.isfile(fname):
            os.unlink(fname)

    # Delete it from the sort list.
    index["photo-order"][album].remove(key)
    del index["map"][key]
    del index["albums"][album][key]

    # Was this the album cover?
    if index["covers"][album] == key:
        # Try to pick a new one.
        if len(index["photo-order"][album]) > 0:
            index["covers"][album] = index["photo-order"][album][0]
        else:
            index["covers"][album] = ""

    # If the album is empty now too, delete it as well.
    if len(index["albums"][album].keys()) == 0:
        del index["albums"][album]
        del index["photo-order"][album]
        del index["covers"][album]
        index["album-order"].remove(album)

    write_index(index)


def order_albums(order):
    """Reorder the albums according to the new order list."""
    index = get_index()

    # Sanity check, make sure all albums are included.
    if len(order) != len(index["album-order"]):
        logger.warning("Can't reorganize albums because the order lists don't match!")
        return None

    for album in index["album-order"]:
        if album not in order:
            logger.warning("Tried reorganizing albums, but {} was missing!".format(album))
            return None

    index["album-order"] = order
    write_index(index)


def order_photos(album, order):
    """Reorder the photos according to the new order list."""
    index = get_index()

    if not album in index["albums"]:
        logger.warning("Album not found: {}".format(album))
        return None

    # Sanity check, make sure all albums are included.
    if len(order) != len(index["photo-order"][album]):
        logger.warning("Can't reorganize photos because the order lists don't match!")
        return None

    for key in index["photo-order"][album]:
        if key not in order:
            logger.warning("Tried reorganizing photos, but {} was missing!".format(key))
            return None

    index["photo-order"][album] = order
    write_index(index)


def upload_from_pc(request):
    """Upload a photo from the user's filesystem.

    This requires the Flask `request` object. Returns a dict with the following
    keys:

    * success: True || False
    * error: if unsuccessful
    * photo: if successful
    """

    form   = request.form
    count  = 0
    status = None
    for upload in reversed(request.files.getlist("file")):
        count += 1

        # Make a temp filename for it.
        filetype = upload.filename.rsplit(".", 1)[-1]
        if not allowed_filetype(upload.filename):
            return dict(success=False, error="Unsupported file extension.")

        tempfile = "{}/rophako-photo-{}.{}".format(Config.site.tempdir, int(time.time()), filetype)
        logger.debug("Save incoming photo to: {}".format(tempfile))
        upload.save(tempfile)

        # All good so far. Process the photo.
        status = process_photo(form, tempfile)
        if not status["success"]:
            return status

    # Multi upload?
    if count > 1:
        status["multi"] = True
    else:
        status["multi"] = False

    return status


def upload_from_www(form):
    """Upload a photo from the Internet.

    This requires the `form` object, but not necessarily Flask's. It just has to
    be a dict with the form keys for the upload.

    Returns the same structure as `upload_from_pc()`.
    """

    url = form.get("url")
    if not url or not allowed_filetype(url):
        return dict(success=False, error="Invalid file extension.")

    # Make a temp filename for it.
    filetype = url.rsplit(".", 1)[1]
    tempfile = "{}/rophako-photo-{}.{}".format(Config.site.tempdir, int(time.time()), filetype)
    logger.debug("Save incoming photo to: {}".format(tempfile))

    # Grab the file.
    try:
        data = requests.get(url).content
    except:
        return dict(success=False, error="Failed to get that URL.")

    fh = open(tempfile, "wb")
    fh.write(data)
    fh.close()

    # All good so far. Process the photo.
    return process_photo(form, tempfile)


def process_photo(form, filename):
    """Formats an incoming photo."""

    # Resize the photo to each of the various sizes and collect their names.
    sizes = dict()
    for size in PHOTO_SCALES.keys():
        sizes[size] = resize_photo(filename, size)

    # Remove the temp file.
    os.unlink(filename)

    # What album are the photos going to?
    album     = form.get("album", "")
    new_album = form.get("new-album", None)
    new_desc  = form.get("new-description", None)
    if album == "" and new_album:
        album = new_album

    # Sanitize the name.
    album = sanitize_name(album)
    if album == "":
        logger.warning("Album name didn't pass sanitization! Fall back to default album name.")
        album = Config.photo.default_album

    # Make up a unique public key for this set of photos.
    key = random_hash()
    while photo_exists(key):
        key = random_hash()
    logger.debug("Photo set public key: {}".format(key))

    # Get the album index to manipulate ordering.
    index = get_index()

    # Update the photo data.
    if not album in index["albums"]:
        index["albums"][album] = {}
    if not "settings" in index:
        index["settings"] = dict()
    if not album in index["settings"]:
        index["settings"][album] = {
            "format": "classic",
            "description": new_desc,
        }

    index["albums"][album][key] = dict(
        ip=remote_addr(),
        author=g.info["session"]["uid"],
        uploaded=int(time.time()),
        caption=form.get("caption", ""),
        description=form.get("description", ""),
        **sizes
    )

    # Maintain a photo map to album.
    index["map"][key] = album

    # Add this pic to the front of the album.
    if not album in index["photo-order"]:
        index["photo-order"][album] = []
    index["photo-order"][album].insert(0, key)

    # If this is a new album, add it to the front of the album ordering.
    if not album in index["album-order"]:
        index["album-order"].insert(0, album)

    # Set the album cover for a new album.
    if not album in index["covers"] or len(index["covers"][album]) == 0:
        index["covers"][album] = key

    # Save changes to the index.
    write_index(index)

    return dict(success=True, photo=key)


def allowed_filetype(filename):
    """Query whether the file extension is allowed."""
    return "." in filename and \
        filename.rsplit(".", 1)[1].lower() in ['jpeg', 'jpe', 'jpg', 'gif', 'png']


def resize_photo(filename, size, crop=None):
    """Resize a photo from the target filename into the requested size.

    Optionally the photo can be cropped with custom parameters.
    """

    # Find the file type.
    filetype = filename.rsplit(".", 1)[1]
    if filetype == "jpeg": filetype = "jpg"

    # Open the image.
    img = Image.open(filename)

    # Make up a unique filename.
    outfile = random_name(filetype)
    target  = os.path.join(Config.photo.root_private, outfile)
    logger.debug("Output file for {} scale: {}".format(size, target))

    # Get the image's dimensions.
    orig_width, orig_height = img.size
    new_width = PHOTO_SCALES[size]
    logger.debug("Original photo dimensions: {}x{}".format(orig_width, orig_height))

    # For the large version, only scale it, don't crop it.
    if size == "large":
        # Do we NEED to scale it?
        if orig_width <= new_width:
            logger.debug("Don't need to scale down the large image!")
            img.save(target)
            return outfile

        # Scale it down.
        ratio      = float(new_width) / float(orig_width)
        new_height = int(float(orig_height) * float(ratio))
        logger.debug("New image dimensions: {}x{}".format(new_width, new_height))
        img = img.resize((new_width, new_height), Image.ANTIALIAS)
        img.save(target)
        return outfile

    # For all other versions, crop them into a square.
    x, y, length = 0, 0, 0

    # Use 0,0 and find the shortest dimension for the length.
    if orig_width > orig_height:
        length = orig_height
    else:
        length = orig_width

    # Did they give us crop coordinates?
    if crop is not None:
        x = crop["x"]
        y = crop["y"]
        if crop["length"] > 0:
            length = crop["length"]

    # Adjust the coords if they're impossible.
    if x < 0:
        logger.warning("X-Coord is less than 0; fixing!")
        x = 0
    if y < 0:
        logger.warning("Y-Coord is less than 0; fixing!")
        y = 0
    if x > orig_width:
        logger.warning("X-Coord is greater than image width; fixing!")
        x = orig_width - length
        if x < 0: x = 0
    if y > orig_height:
        logger.warning("Y-Coord is greater than image height; fixing!")
        y = orig_height - length
        if y < 0: y = 0

    # Make sure the crop box fits.
    if x + length > orig_width:
        diff = x + length - orig_width
        logger.warning("Crop box is outside the right edge of the image by {}px; fixing!".format(diff))
        length -= diff
    if y + length > orig_height:
        diff = y + length - orig_height
        logger.warning("Crop box is outside the bottom edge of the image by {}px; fixing!".format(diff))
        length -= diff

    # Do we need to scale?
    if new_width == length:
        logger.debug("Image doesn't need to be cropped or scaled!")
        img.save(target)
        return outfile

    # Crop to the requested box.
    logger.debug("Cropping the photo")
    img = img.crop((x, y, x+length, y+length))

    # Scale it to the proper dimensions.
    img = img.resize((new_width, new_width), Image.ANTIALIAS)
    img.save(target)
    return outfile


def get_index():
    """Get the photo album index, or a new empty DB if it doesn't exist."""
    if JsonDB.exists("photos/index"):
        return JsonDB.get("photos/index")

    return {
        "albums": {},      # Album data
        "map": {},         # Map photo keys to albums
        "covers": {},      # Album cover photos
        "photo-order": {}, # Ordering of photos in albums
        "album-order": [], # Ordering of albums themselves
    }


def write_index(index):
    """Save the index back to the DB."""
    return JsonDB.commit("photos/index", index)


def random_name(filetype):
    """Get a random available file name to save a new photo."""
    filetype = filetype.lower()
    outfile = random_hash() + "." + filetype
    while os.path.isfile(os.path.join(Config.photo.root_private, outfile)):
        outfile = random_hash() + "." + filetype
    return outfile


def random_hash():
    """Get a short random hash to use as the base name for a photo."""
    md5 = hashlib.md5()
    md5.update(str(random.randint(0, 1000000)).encode("utf-8"))
    return md5.hexdigest()[:8]