"""!@package grass.temporal

@brief GRASS Python scripting module (temporal GIS functions)

Temporal GIS related functions to be used in temporal GIS Python library package.

Usage:

@code
import grass.temporal as tgis

tgis.print_temporal_relations(maps)
...
@endcode

(C) 2008-2011 by the GRASS Development Team
This program is free software under the GNU General Public
License (>=v2). Read the file COPYING that comes with GRASS
for details.

@author Soeren Gebbert
"""
from abstract_map_dataset import *
from datetime_math import *

###############################################################################


class temporal_topology_builder(object):
    """!This class is designed to build the temporal topology 
       based on a lists of maps

        Example:
        @code
        # We have a space time raster dataset and build a map list
        # from all registered maps ordered by start time
        maps = strds.get_registered_maps_as_objects()

        # Now lets build the temporal topology of the maps in the list
        tb = temporal_topology_builder()
        tb.build(maps)

        for _map in tb:
            _map.print_temporal_topology_info()
            _follows = _map.get_follows()
            if _follows:
                for f in _follows:
                    f.print_temporal_topology_info()

        # Using the next and previous methods, we can iterate over the
        # topological related maps in this way

        _first = tb.get_first()

        while _first:
            _first.print_temporal_topology_info()
            _first = _first.next()

        # Dictionary like accessed
        _map = tb["name@mapset"]
        @endcode

    """
    def __init__(self):
        self._reset()

    def _reset(self):
        self._store = {}
        self._first = None
        self._temporal_iteratable = False

    def _set_first(self, first):
        self._first = first
        self._insert(first)

    def _detect_first(self):
        if len(self) > 0:
            prev_ = self._store.values()[0]
            while prev_ is not None:
                self._first = prev_
                prev_ = prev_.temporal_prev()

    def _insert(self, t):
        self._store[t.get_id()] = t

    def get_first(self):
        """!Return the first map with the earliest start time

           @return The map with the earliest start time
        """
        return self._first

    def _build_internal_iteratable(self, maps):
        """!Build an iteratable temporal topology structure for all maps in 
           the list and store the maps internally

           Basically the "next" and "prev" relations will be set in the 
           temporal topology structure of each map
           The maps will be added to the object, so they can be 
           accessed using the iterator of this class

           @param maps: A sorted (by start_time)list of abstract_dataset 
                        objects with initiated temporal extent
        """
        self._build_iteratable(maps)

        for _map in maps:
            self._insert(_map)

        # Detect the first map
        self._detect_first()

    def _build_iteratable(self, maps):
        """!Build an iteratable temporal topology structure for 
           all maps in the list

           Basically the "next" and "prev" relations will be set in 
           the temporal topology structure of each map.

           @param maps: A sorted (by start_time)list of abstract_dataset 
                        objects with initiated temporal extent
        """
        for i in xrange(len(maps)):
            offset = i + 1
            for j in xrange(offset, len(maps)):
                # Get the temporal relationship
                relation = maps[j].temporal_relation(maps[i])

                # Build the next reference
                if relation != "equivalent" and relation != "started":
                    maps[i].set_temporal_next(maps[j])
                    break

        for map_ in maps:
            next_ = map_.temporal_next()
            if next_:
                next_.set_temporal_prev(map_)
            map_.set_temporal_topology_build_true()

    def build2(self, mapsA, mapsB):
        """!Build the temporal topology structure between 
           two ordered lists of maps

           This method builds the temporal topology from mapsA to 
           mapsB and vice verse. The temporal topology structure of each map, 
           defined in class temporal_map_relations,
           will be reseted and rebuild for mapsA and mapsB.

           After building the temporal topology the modified 
           map objects of mapsA can be accessed
           in the same way as a dictionary using there id. 
           The implemented iterator assures
           the chronological iteration over the mapsA.

           @param mapsA: A sorted list (by start_time) of abstract_dataset 
                         objects with initiated temporal extent
           @param mapsB: A sorted list (by start_time) of abstract_dataset 
                         objects with initiated temporal extent
        """

        if mapsA == mapsB:
            self.build(mapsA, True)
            return

        for map_ in mapsA:
            map_.reset_temporal_topology()

        for map_ in mapsB:
            map_.reset_temporal_topology()

        for i in xrange(len(mapsA)):
            for j in xrange(len(mapsB)):

                # Get the temporal relationship
                relation = mapsB[j].temporal_relation(mapsA[i])

                if relation == "before":
                    continue

                if relation == "equivalent":
                    mapsB[j].append_temporal_equivalent(mapsA[i])
                    mapsA[i].append_temporal_equivalent(mapsB[j])
                elif relation == "follows":
                    mapsB[j].append_temporal_follows(mapsA[i])
                    mapsA[i].append_temporal_precedes(mapsB[j])
                elif relation == "precedes":
                    mapsB[j].append_temporal_precedes(mapsA[i])
                    mapsA[i].append_temporal_follows(mapsB[j])
                elif relation == "during" or relation == "starts" or \
                     relation == "finishes":
                    mapsB[j].append_temporal_during(mapsA[i])
                    mapsA[i].append_temporal_contains(mapsB[j])
                elif relation == "contains" or relation == "started" or \
                     relation == "finished":
                    mapsB[j].append_temporal_contains(mapsA[i])
                    mapsA[i].append_temporal_during(mapsB[j])
                elif relation == "overlaps":
                    mapsB[j].append_temporal_overlaps(mapsA[i])
                    mapsA[i].append_temporal_overlapped(mapsB[j])
                elif relation == "overlapped":
                    mapsB[j].append_temporal_overlapped(mapsA[i])
                    mapsA[i].append_temporal_overlaps(mapsB[j])

                # Break if the next map follows and the over-next maps is after
                if relation == "follows":
                    if j < len(mapsB) - 1:
                        relation = mapsB[j + 1].temporal_relation(mapsA[i])
                        if relation == "after":
                            break
                # Break if the the next map is after
                if relation == "after":
                    break

        self._build_internal_iteratable(mapsA)
        self._build_iteratable(mapsB)

    def build(self, maps):
        """!Build the temporal topology structure

           This method builds the temporal topology based on 
           all maps in the provided map list.
           The temporal topology structure of each map, 
           defined in class temporal_map_relations,
           will be reseted and rebuild.

           After building the temporal topology the 
           modified map objects can be accessed
           in the same way as a dictionary using there id. 
           The implemented iterator assures
           the chronological iteration over the maps.

           @param maps: A sorted list (by start_time) of abstract_dataset 
                        objects with initiated temporal extent
        """
        for map_ in maps:
            map_.reset_temporal_topology()

        for i in xrange(len(maps)):
            offset = i + 1
            for j in xrange(offset, len(maps)):

                # Get the temporal relationship
                relation = maps[j].temporal_relation(maps[i])

                # The start time of map j is equal or later than map i
                if relation == "equivalent":
                    maps[j].append_temporal_equivalent(maps[i])
                    maps[i].append_temporal_equivalent(maps[j])
                elif relation == "follows":
                    maps[j].append_temporal_follows(maps[i])
                    maps[i].append_temporal_precedes(maps[j])
                elif relation == "during" or relation == "starts" or \
                     relation == "finishes":
                    maps[j].append_temporal_during(maps[i])
                    maps[i].append_temporal_contains(maps[j])
                elif relation == "started":
                    # Consider equal start time, in case 
                    # "started" map j contains map i
                    maps[j].append_temporal_contains(maps[i])
                    maps[i].append_temporal_during(maps[j])
                elif relation == "overlaps":
                    maps[j].append_temporal_overlaps(maps[i])
                    maps[i].append_temporal_overlapped(maps[j])

                # Break if the last map follows
                if relation == "follows":
                    if j < len(maps) - 1:
                        relation = maps[j + 1].temporal_relation(maps[i])
                        if relation == "after":
                            break
                # Break if the the next map is after
                if relation == "after":
                    break

        self._build_internal_iteratable(maps)

    def __iter__(self):
        start_ = self._first
        while start_ is not None:
            yield start_
            start_ = start_.temporal_next()

    def __getitem__(self, index):
        return self._store[index.get_id()]

    def __len__(self):
        return len(self._store)

    def __contains__(self, _map):
        return _map in self._store.values()


###############################################################################

def print_temporal_topology_relationships(maps1, maps2):
    """!Print the temporal relation matrix of the temporal ordered 
       map lists maps1 and maps2 to stdout.

        @param maps1: A sorted (by start_time) list of abstract_dataset 
                      objects with initiated temporal extent
        @param maps2: A sorted (by start_time) list of abstract_dataset 
                      objects with initiated temporal extent
    """

    identical = False
    use_id = True

    if maps1 == maps2:
        identical = True
        use_id = False

    for i in range(len(maps1)):
        if identical == True:
            start = i + 1
        else:
            start = 0
        for j in range(start, len(maps2)):
            relation = maps1[j].temporal_relation(maps2[i])

            if use_id == False:
                print maps2[j].base.get_name(
                ), relation, maps1[i].base.get_name()
            else:
                print maps2[j].base.get_id(), relation, maps1[i].base.get_id()

            # Break if the last map follows
            if relation == "follows":
                if j < len(maps1) - 1:
                    relation = maps1[j + 1].temporal_relation(maps2[i])
                    if relation == "after":
                        break
            # Break if the the next map is after
            if relation == "after":
                break

###############################################################################


def count_temporal_topology_relationships(maps1, maps2):
    """!Count the temporal relations between the two lists of maps

        The map lists must be ordered by start time. 
        Temporal relations are counted by analyzing the sparse 
        (upper right side in case maps1 == maps2) temporal relationships matrix.

        @param maps1: A sorted (by start_time) list of abstract_dataset 
                      objects with initiated temporal extent
        @param maps2: A sorted (by start_time) list of abstract_dataset 
                      objects with initiated temporal extent
        @return A dictionary with counted temporal relationships
    """

    tcount = {}
    identical = False

    if maps1 == maps2:
        identical = True

    for i in range(len(maps1)):
        if identical:
            start = i + 1
        else:
            start = 0
        for j in range(start, len(maps2)):
            relation = maps1[j].temporal_relation(maps2[i])

            if relation == "before":
                continue

            if relation in tcount:
                tcount[relation] = tcount[relation] + 1
            else:
                tcount[relation] = 1

            # Break if the last map follows
            if relation == "follows":
                if j < len(maps1) - 1:
                    relation = maps1[j + 1].temporal_relation(maps2[i])
                    if relation == "after":
                        break
            # Break if the the next map is after
            if relation == "after":
                break

    return tcount