osdf rearchitecture into apps and libs

Change-Id: I2db2f8e252bd5e60807b2ffabf5a5b193a789f7a
Signed-off-by: vrvarma <vv8305@att.com>
Issue-ID: OPTFRA-637

9 files changed, 693 insertions, 0 deletions

diff --git a/apps/pci/optimizers/__init__.py b/apps/pci/optimizers/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/apps/pci/optimizers/__init__.py
diff --git a/apps/pci/optimizers/configdb.py b/apps/pci/optimizers/configdb.py
new file mode 100644
index 0000000..8f003c2
--- /dev/null
+++ b/apps/pci/optimizers/configdb.py
@@ -0,0 +1,69 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2018 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+from datetime import datetime as dt
+
+from osdf.logging.osdf_logging import debug_log
+from osdf.utils.interfaces import RestClient
+
+
+def request(req_object, osdf_config, flat_policies):
+    """
+    Process a configdb request from a Client (build Conductor API call, make the call, return result)
+    :param req_object: Request parameters from the client
+    :param osdf_config: Configuration specific to OSDF application (core + deployment)
+    :param flat_policies: policies related to PCI Opt (fetched based on request)
+    :return: response from ConfigDB (accounting for redirects from Conductor service
+    """
+    cell_list_response = {}
+    config = osdf_config.deployment
+    local_config = osdf_config.core
+    uid, passwd = config['configDbUserName'], config['configDbPassword']
+    req_id = req_object['requestInfo']['requestId']
+    transaction_id = req_object['requestInfo']['transactionId']
+    headers = dict(transaction_id=transaction_id)
+
+    network_id = req_object['cellInfo']['networkId']
+
+    cell_list_response['network_id'] = network_id
+
+    ts = dt.strftime(dt.now(), '%Y-%m-%d %H:%M:%S%z')
+
+    rc = RestClient(userid=uid, passwd=passwd, method="GET", log_func=debug_log.debug, headers=headers)
+
+    cell_list_url = '{}/{}/{}/{}'.format(config['configDbUrl'], config['configDbGetCellListUrl'], network_id, ts)
+
+    cell_list_resp = rc.request(raw_response=True, url=cell_list_url)
+    cell_resp = cell_list_resp.json()
+
+    cell_list = []
+    count = 0
+    for cell_id in cell_resp:
+        cell_info = {'cell_id': cell_id, 'id': count}
+        nbr_list_url = '{}/{}/{}/{}'.format(config['configDbUrl'], config['configDbGetNbrListUrl'], cell_id, ts)
+        nbr_list_raw = rc.request(url=nbr_list_url, raw_response=True)
+        cell_info['nbr_list'] = get_neighbor_list(nbr_list_raw.json())
+        cell_list.append(cell_info)
+        count += 1
+
+    cell_list_response['cell_list'] = cell_list
+    return cell_resp, cell_list_response
+
+
+def get_neighbor_list(nbr_list_response):
+    return nbr_list_response.get('nbrList', [])
diff --git a/apps/pci/optimizers/pci_opt_processor.py b/apps/pci/optimizers/pci_opt_processor.py
new file mode 100644
index 0000000..9948d55
--- /dev/null
+++ b/apps/pci/optimizers/pci_opt_processor.py
@@ -0,0 +1,123 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2018 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+import traceback
+
+from onaplogging.mdcContext import MDC
+from requests import RequestException
+
+from osdf.logging.osdf_logging import metrics_log, MH, error_log
+from osdf.operation.error_handling import build_json_error_body
+from osdf.utils.interfaces import get_rest_client
+from .configdb import request as config_request
+from .solver.optimizer import pci_optimize as optimize
+from .solver.pci_utils import get_cell_id, get_pci_value
+from osdf.utils.mdc_utils import mdc_from_json
+
+"""
+This application generates PCI Optimization API calls using the information received from PCI-Handler-MS, SDN-C
+and Policy.
+"""
+
+
+def process_pci_optimation(request_json, osdf_config, flat_policies):
+    """
+    Process a PCI request from a Client (build config-db, policy and  API call, make the call, return result)
+    :param req_object: Request parameters from the client
+    :param osdf_config: Configuration specific to OSDF application (core + deployment)
+    :param flat_policies: policies related to pci (fetched based on request)
+    :return: response from PCI Opt
+    """
+    try:
+        mdc_from_json(request_json)
+        rc = get_rest_client(request_json, service="pcih")
+        req_id = request_json["requestInfo"]["requestId"]
+        cell_info_list, network_cell_info = config_request(request_json, osdf_config, flat_policies)
+        pci_response = get_solutions(cell_info_list, network_cell_info, request_json)
+
+        metrics_log.info(MH.inside_worker_thread(req_id))
+    except Exception as err:
+        error_log.error("Error for {} {}".format(req_id, traceback.format_exc()))
+
+        try:
+            body = build_json_error_body(err)
+            metrics_log.info(MH.sending_response(req_id, "ERROR"))
+            rc.request(json=body, noresponse=True)
+        except RequestException as err:
+            MDC.put('requestID',req_id)
+            error_log.error("Error sending asynchronous notification for {} {}".format(req_id, traceback.format_exc()))
+        raise err
+
+
+    try:
+        metrics_log.info(MH.calling_back_with_body(req_id, rc.url, pci_response))
+        rc.request(json=pci_response, noresponse=True)
+    except RequestException:  # can't do much here but log it and move on
+        error_log.error("Error sending asynchronous notification for {} {}".format(req_id, traceback.format_exc()))
+
+
+def get_solutions(cell_info_list, network_cell_info, request_json):
+    status, pci_solutions, anr_solutions = build_solution_list(cell_info_list, network_cell_info, request_json)
+    return {
+        "transactionId": request_json['requestInfo']['transactionId'],
+        "requestId": request_json["requestInfo"]["requestId"],
+        "requestStatus": "completed",
+        "statusMessage": status,
+        "solutions": {
+            'networkId': request_json['cellInfo']['networkId'],
+            'pciSolutions': pci_solutions,
+            'anrSolutions': anr_solutions
+        }
+    }
+
+
+def build_solution_list(cell_info_list, network_cell_info, request_json):
+    status = "success"
+    req_id = request_json["requestInfo"]["requestId"]
+    try:
+        opt_solution = optimize(network_cell_info, cell_info_list, request_json)
+        pci_solutions = build_pci_solution(network_cell_info, opt_solution['pci'])
+        anr_solutions = build_anr_solution(network_cell_info, opt_solution.get('removables', {}))
+    except RuntimeError:
+        error_log.error("Failed finding solution for {} {}".format(req_id, traceback.format_exc()))
+        status = "failed"
+    return status, pci_solutions, anr_solutions
+
+
+def build_pci_solution(network_cell_info, pci_solution):
+    pci_solutions = []
+    for k, v in pci_solution.items():
+        old_pci = get_pci_value(network_cell_info, k)
+        if old_pci != v:
+            response = {
+                'cellId': get_cell_id(network_cell_info, k),
+                'pci': v
+            }
+            pci_solutions.append(response)
+    return pci_solutions
+
+
+def build_anr_solution(network_cell_info, removables):
+    anr_solutions = []
+    for k, v in removables.items():
+        response = {
+            'cellId': get_cell_id(network_cell_info, k),
+            'removeableNeighbors': list(map(lambda x: get_cell_id(network_cell_info, x), v))
+        }
+        anr_solutions.append(response)
+    return anr_solutions
diff --git a/apps/pci/optimizers/solver/__init__.py b/apps/pci/optimizers/solver/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/apps/pci/optimizers/solver/__init__.py
diff --git a/apps/pci/optimizers/solver/min_confusion.mzn b/apps/pci/optimizers/solver/min_confusion.mzn
new file mode 100644
index 0000000..ff56c18
--- /dev/null
+++ b/apps/pci/optimizers/solver/min_confusion.mzn
@@ -0,0 +1,98 @@
+% -------------------------------------------------------------------------
+%   Copyright (c) 2018 AT&T Intellectual Property
+%
+%   Licensed under the Apache License, Version 2.0 (the "License");
+%   you may not use this file except in compliance with the License.
+%   You may obtain a copy of the License at
+%
+%       http://www.apache.org/licenses/LICENSE-2.0
+%
+%   Unless required by applicable law or agreed to in writing, software
+%   distributed under the License is distributed on an "AS IS" BASIS,
+%   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%   See the License for the specific language governing permissions and
+%   limitations under the License.
+%
+% -------------------------------------------------------------------------
+%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Parameters and its assertions
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Number of cells/radios.
+int: NUM_NODES;
+
+% Maximum number of Physical Cell Identifiers to be assigned to the nodes.
+int: NUM_PCIS;
+
+% Number of edges between neighbor nodes. There is a edge (i,j) if and only
+% if nodes i and j are neighbors, i.e., an user equipment (UE) can make
+% handoff between i and j. Such edges are used to avoid **COLLISION**, i.e.,
+% to guarantee that nodes i and j have different PCIs.
+int: NUM_NEIGHBORS;
+
+% Each line represents an edge between direct neighbors as defined before.
+array[1..NUM_NEIGHBORS, 1..2] of int: NEIGHBORS;
+
+% Number of undirect neighbor pairs (j, k) such that both j and k are direct
+% neighbors of node i, i.e., (j, k) exits if and only if exists (i, j) and
+% (i, k). Nodes (i, k) can generate "confunsions" in the network if they have
+% the same PCI. Such edges are used to avoid/minimize **CONFUSIONS**.
+int: NUM_SECOND_LEVEL_NEIGHBORS;
+
+% Each line represents an edge between undirect neighbors as defined before.
+array[1..NUM_SECOND_LEVEL_NEIGHBORS, 1..2] of int: SECOND_LEVEL_NEIGHBORS;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Decision variables
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Defines the PCI for each node.
+array[0..NUM_NODES-1] of var 0..NUM_PCIS-1: pci;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Constraints
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Direct neighbors must have different PCIs for avoid **COLLISION**.
+constraint
+forall(i in 1..NUM_NEIGHBORS)(
+    pci[NEIGHBORS[i, 1]] != pci[NEIGHBORS[i, 2]]
+);
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Objective function
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Total number of confusions.
+var int: total_confusions =
+    sum([bool2int(pci[SECOND_LEVEL_NEIGHBORS[i, 1]] ==
+                  pci[SECOND_LEVEL_NEIGHBORS[i, 2]])
+         | i in 1..NUM_SECOND_LEVEL_NEIGHBORS]);
+
+% Minimize the total number of confusions.
+solve :: int_search(pci, smallest, indomain_min, complete)
+minimize total_confusions;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Output
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+output
+["PCI assigment"] ++
+["\nnode,pci"] ++
+[
+    "\n" ++ show(node) ++ "," ++ show(pci[node])
+| node in 0..NUM_NODES-1
+] ++
+
+["\n\nConfusions"] ++
+["\nTotal confusions: " ++ show(total_confusions)] ++
+["\nConfusion pairs"] ++
+[
+    "\n" ++ show(SECOND_LEVEL_NEIGHBORS[i, 1]) ++ "," ++
+    show(SECOND_LEVEL_NEIGHBORS[i, 2])
+| i in 1..NUM_SECOND_LEVEL_NEIGHBORS where
+  fix(pci[SECOND_LEVEL_NEIGHBORS[i, 1]] == pci[SECOND_LEVEL_NEIGHBORS[i, 2]])
+]
diff --git a/apps/pci/optimizers/solver/min_confusion_inl.mzn b/apps/pci/optimizers/solver/min_confusion_inl.mzn
new file mode 100644
index 0000000..0f0fc91
--- /dev/null
+++ b/apps/pci/optimizers/solver/min_confusion_inl.mzn
@@ -0,0 +1,140 @@
+% -------------------------------------------------------------------------
+%   Copyright (c) 2018 AT&T Intellectual Property
+%
+%   Licensed under the Apache License, Version 2.0 (the "License");
+%   you may not use this file except in compliance with the License.
+%   You may obtain a copy of the License at
+%
+%       http://www.apache.org/licenses/LICENSE-2.0
+%
+%   Unless required by applicable law or agreed to in writing, software
+%   distributed under the License is distributed on an "AS IS" BASIS,
+%   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%   See the License for the specific language governing permissions and
+%   limitations under the License.
+%
+% -------------------------------------------------------------------------
+%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Parameters and its assertions
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Number of cells/radios.
+int: NUM_NODES;
+
+% Maximum number of Physical Cell Identifiers to be assigned to the nodes.
+int: NUM_PCIS;
+
+% Number of edges between neighbor nodes. There is a edge (i,j) if and only
+% if nodes i and j are neighbors, i.e., an user equipment (UE) can make
+% handoff between i and j. Such edges are used to avoid **COLLISION**, i.e.,
+% to guarantee that nodes i and j have different PCIs.
+int: NUM_NEIGHBORS;
+
+% Each line represents an edge between direct neighbors as defined before.
+array[1..NUM_NEIGHBORS, 1..2] of int: NEIGHBORS;
+
+% Number of undirect neighbor pairs (j, k) such that both j and k are direct
+% neighbors of node i, i.e., (j, k) exits if and only if exists (i, j) and
+% (i, k). Nodes (i, k) can generate "confunsions" in the network if they have
+% the same PCI. Such edges are used to avoid/minimize **CONFUSIONS**.
+int: NUM_SECOND_LEVEL_NEIGHBORS;
+
+% Each line represents an edge between undirect neighbors as defined before.
+array[1..NUM_SECOND_LEVEL_NEIGHBORS, 1..2] of int: SECOND_LEVEL_NEIGHBORS;
+
+% Number of ignorable neighbor links. Such links can be ignored during
+% optimization if needed.
+int: NUM_IGNORABLE_NEIGHBOR_LINKS;
+
+% The links that can be ignored if needed. Each line represents the two ends
+% of the links, like the previous structures.
+array[1..NUM_IGNORABLE_NEIGHBOR_LINKS, 1..2] of int: IGNORABLE_NEIGHBOR_LINKS;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Decision variables
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Defines the PCI for each node.
+array[0..NUM_NODES-1] of var 0..NUM_PCIS-1: pci;
+
+array[1..NUM_IGNORABLE_NEIGHBOR_LINKS] of var 0..1: used_ignorables;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Constraints
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Direct neighbors must have different PCIs for avoid **COLLISION**.
+% Forced links.
+constraint
+forall(i in 1..NUM_NEIGHBORS, j in 1..NUM_IGNORABLE_NEIGHBOR_LINKS
+    where
+        NEIGHBORS[i, 1] != IGNORABLE_NEIGHBOR_LINKS[j, 1] \/
+        NEIGHBORS[i, 2] != IGNORABLE_NEIGHBOR_LINKS[j, 2]
+)(
+    pci[NEIGHBORS[i, 1]] != pci[NEIGHBORS[i, 2]]
+);
+
+
+% Ignorable links.
+constraint
+forall(i in 1..NUM_NEIGHBORS, j in 1..NUM_IGNORABLE_NEIGHBOR_LINKS
+    where
+        NEIGHBORS[i, 1] == IGNORABLE_NEIGHBOR_LINKS[j, 1] /\
+        NEIGHBORS[i, 2] == IGNORABLE_NEIGHBOR_LINKS[j, 2]
+)(
+    used_ignorables[j] >= bool2int(pci[NEIGHBORS[i, 1]] == pci[NEIGHBORS[i, 2]])
+);
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Objective function
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Total number of confusions.
+var int: total_confusions =
+    sum([bool2int(pci[SECOND_LEVEL_NEIGHBORS[i, 1]] ==
+                  pci[SECOND_LEVEL_NEIGHBORS[i, 2]])
+         | i in 1..NUM_SECOND_LEVEL_NEIGHBORS]);
+
+% Total number of used ignorables links.
+var int: total_used_ignorables = sum(used_ignorables);
+
+solve :: int_search(pci, smallest, indomain_min, complete)
+
+% Minimize the total number of confusions.
+%minimize total_confusions;
+
+% Minimize the total number of confusions first,
+% then the number of used ignorables links.
+minimize (2 * NUM_IGNORABLE_NEIGHBOR_LINKS * total_confusions) +
+         total_used_ignorables;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Output
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+output
+["PCI assigment"] ++
+["\nnode,pci"] ++
+[
+    "\n" ++ show(node) ++ "," ++ show(pci[node])
+| node in 0..NUM_NODES-1
+] ++
+["\n\nTotal used ignorables links: " ++ show(total_used_ignorables)] ++
+["\nUsed ignorables links: "] ++
+[
+    "\n" ++ show(IGNORABLE_NEIGHBOR_LINKS[i, 1]) ++
+    ","  ++ show(IGNORABLE_NEIGHBOR_LINKS[i, 2])
+    | i in 1..NUM_IGNORABLE_NEIGHBOR_LINKS where fix(used_ignorables[i] > 0)
+] ++
+["\n\nConfusions"] ++
+["\nTotal confusions: " ++ show(total_confusions)] ++
+["\nConfusion pairs"] ++
+[
+    "\n" ++ show(SECOND_LEVEL_NEIGHBORS[i, 1]) ++ "," ++
+    show(SECOND_LEVEL_NEIGHBORS[i, 2])
+    | i in 1..NUM_SECOND_LEVEL_NEIGHBORS where
+      fix(pci[SECOND_LEVEL_NEIGHBORS[i, 1]] == pci[SECOND_LEVEL_NEIGHBORS[i, 2]])
+]
+
diff --git a/apps/pci/optimizers/solver/no_conflicts_no_confusion.mzn b/apps/pci/optimizers/solver/no_conflicts_no_confusion.mzn
new file mode 100644
index 0000000..0a9b3e3
--- /dev/null
+++ b/apps/pci/optimizers/solver/no_conflicts_no_confusion.mzn
@@ -0,0 +1,86 @@
+% -------------------------------------------------------------------------
+%   Copyright (c) 2018 AT&T Intellectual Property
+%
+%   Licensed under the Apache License, Version 2.0 (the "License");
+%   you may not use this file except in compliance with the License.
+%   You may obtain a copy of the License at
+%
+%       http://www.apache.org/licenses/LICENSE-2.0
+%
+%   Unless required by applicable law or agreed to in writing, software
+%   distributed under the License is distributed on an "AS IS" BASIS,
+%   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%   See the License for the specific language governing permissions and
+%   limitations under the License.
+%
+% -------------------------------------------------------------------------
+%
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Parameters and its assertions
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Number of cells/radios.
+int: NUM_NODES;
+
+% Maximum number of Physical Cell Identifiers to be assigned to the nodes.
+int: NUM_PCIS;
+
+% Number of edges between neighbor nodes. There is a edge (i,j) if and only
+% if nodes i and j are neighbors, i.e., an user equipment (UE) can make
+% handoff between i and j. Such edges are used to avoid **COLLISIONS**, i.e.,
+% to guarantee that nodes i and j have different PCIs.
+int: NUM_NEIGHBORS;
+
+% Each line represents an edge between direct neighbors as defined before.
+array[1..NUM_NEIGHBORS, 1..2] of int: NEIGHBORS;
+
+% Number of undirect neighbor pairs (j, k) such that both j and k are direct
+% neighbors of node i, i.e., (j, k) exits if and only if exists (i, j) and
+% (i, k). Nodes (i, k) can generate "confunsions" in the network if they have
+% the same PCI. Such edges are used to avoid/minimize **CONFUSIONS**.
+int: NUM_SECOND_LEVEL_NEIGHBORS;
+
+% Each line represents an edge between undirect neighbors as defined before.
+array[1..NUM_SECOND_LEVEL_NEIGHBORS, 1..2] of int: SECOND_LEVEL_NEIGHBORS;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Decision variables
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Defines the PCI for each node.
+array[0..NUM_NODES-1] of var 0..NUM_PCIS-1: pci;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Constraints
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Direct neighbors must have different PCIs for avoid **COLLISION**.
+constraint
+forall(i in 1..NUM_NEIGHBORS)(
+    pci[NEIGHBORS[i, 1]] != pci[NEIGHBORS[i, 2]]
+);
+
+% Undirect neighbors must have different PCIs for avoid **CONFUSIONS**.
+constraint
+forall(i in 1..NUM_SECOND_LEVEL_NEIGHBORS)(
+    pci[SECOND_LEVEL_NEIGHBORS[i, 1]] != pci[SECOND_LEVEL_NEIGHBORS[i, 2]]
+);
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Objective function
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% Just satisfy the problem.
+solve :: int_search(pci, smallest, indomain_min, complete) satisfy;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Output
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+output
+["node,pci\n"] ++
+[
+    show(node) ++ "," ++ show(pci[node]) ++ "\n"
+| node in 0..NUM_NODES-1
+]
diff --git a/apps/pci/optimizers/solver/optimizer.py b/apps/pci/optimizers/solver/optimizer.py
new file mode 100644
index 0000000..0a6d5a4
--- /dev/null
+++ b/apps/pci/optimizers/solver/optimizer.py
@@ -0,0 +1,137 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2018 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+import itertools
+import os
+from collections import defaultdict
+
+import pymzn
+
+from .pci_utils import get_id
+
+BASE_DIR = os.path.dirname(__file__)
+
+
+def pci_optimize(network_cell_info, cell_info_list, request_json):
+    neighbor_edges = get_neighbor_list(network_cell_info)
+    second_level_edges = get_second_level_neighbor(network_cell_info)
+    ignorable_links = get_ignorable_links(network_cell_info, request_json)
+    anr_flag = is_anr(request_json)
+
+    dzn_data = build_dzn_data(cell_info_list, ignorable_links, neighbor_edges, second_level_edges, anr_flag)
+
+    return build_pci_solution(dzn_data, ignorable_links, anr_flag)
+
+
+def build_pci_solution(dzn_data, ignorable_links, anr_flag):
+    mzn_solution = solve(get_mzn_model(anr_flag), dzn_data)
+
+    solution = {'pci': mzn_solution[0]['pci']}
+
+    if anr_flag:
+        removables = defaultdict(list)
+        used_ignorables = mzn_solution[0]['used_ignorables']
+        index = 0
+        for i in ignorable_links:
+            if used_ignorables[index] > 0:
+                removables[i[0]].append(i[1])
+            index += 1
+        solution['removables'] = removables
+    return solution
+
+
+def build_dzn_data(cell_info_list, ignorable_links, neighbor_edges, second_level_edges, anr_flag):
+    dzn_data = {
+        'NUM_NODES': len(cell_info_list),
+        'NUM_PCIS': len(cell_info_list),
+        'NUM_NEIGHBORS': len(neighbor_edges),
+        'NEIGHBORS': get_list(neighbor_edges),
+        'NUM_SECOND_LEVEL_NEIGHBORS': len(second_level_edges),
+        'SECOND_LEVEL_NEIGHBORS': get_list(second_level_edges)
+    }
+    if anr_flag:
+        dzn_data['NUM_IGNORABLE_NEIGHBOR_LINKS'] = len(ignorable_links)
+        dzn_data['IGNORABLE_NEIGHBOR_LINKS'] = get_list(ignorable_links)
+    return dzn_data
+
+
+def get_mzn_model(anr_flag):
+    if anr_flag:
+        mzn_model = os.path.join(BASE_DIR, 'min_confusion_inl.mzn')
+    else:
+        mzn_model = os.path.join(BASE_DIR, 'no_conflicts_no_confusion.mzn')
+    return mzn_model
+
+
+def is_anr(request_json):
+    return 'pci-anr' in request_json["requestInfo"]["optimizers"]
+
+
+def get_list(edge_list):
+    array_list = []
+    for s in edge_list:
+        array_list.append([s[0], s[1]])
+    return sorted(array_list)
+
+
+def solve(mzn_model, dzn_data):
+    return pymzn.minizinc(mzn=mzn_model, data=dzn_data)
+
+
+def get_neighbor_list(network_cell_info):
+    neighbor_list = set()
+    for cell in network_cell_info['cell_list']:
+        add_to_neighbor_list(network_cell_info, cell, neighbor_list)
+    return neighbor_list
+
+
+def add_to_neighbor_list(network_cell_info, cell, neighbor_list):
+    for nbr in cell.get('nbr_list', []):
+        host_id = cell['id']
+        nbr_id = get_id(network_cell_info, nbr['targetCellId'])
+        if nbr_id and host_id != nbr_id:
+            neighbor_list.add((host_id, nbr_id))
+
+
+def get_second_level_neighbor(network_cell_info):
+    second_neighbor_list = set()
+    for cell in network_cell_info['cell_list']:
+        comb_list = build_second_level_list(network_cell_info, cell)
+        for comb in comb_list:
+            if comb[0] and comb[1]:
+                second_neighbor_list.add((comb[0], comb[1]))
+    return sorted(second_neighbor_list)
+
+
+def build_second_level_list(network_cell_info, cell):
+    second_nbr_list = []
+    for nbr in cell.get('nbr_list', []):
+        second_nbr_list.append(get_id(network_cell_info, nbr['targetCellId']))
+    return [list(elem) for elem in list(itertools.combinations(second_nbr_list, 2))]
+
+
+def get_ignorable_links(network_cell_info, request_json):
+    ignorable_list = set()
+    anr_input_list = request_json["cellInfo"].get('anrInputList', [])
+    if anr_input_list:
+        for anr_info in anr_input_list:
+            cell_id = get_id(network_cell_info, anr_info['cellId'])
+            anr_removable = anr_info.get('removeableNeighbors', [])
+            for anr in anr_removable:
+                ignorable_list.add((cell_id, get_id(network_cell_info, anr)))
+    return ignorable_list
diff --git a/apps/pci/optimizers/solver/pci_utils.py b/apps/pci/optimizers/solver/pci_utils.py
new file mode 100644
index 0000000..04829cf
--- /dev/null
+++ b/apps/pci/optimizers/solver/pci_utils.py
@@ -0,0 +1,40 @@
+# -------------------------------------------------------------------------
+#   Copyright (c) 2018 AT&T Intellectual Property
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# -------------------------------------------------------------------------
+#
+
+
+def get_id(network_cell_info, cell_id):
+    for i in network_cell_info['cell_list']:
+        if i['cell_id'] == cell_id:
+            return i['id']
+    return None
+
+
+def get_cell_id(network_cell_info, id):
+    for i in network_cell_info['cell_list']:
+        if i['id'] == id:
+            return i['cell_id']
+    return None
+
+
+def get_pci_value(network_cell_info, id):
+    cell_id = get_cell_id(network_cell_info, id)
+    for i in network_cell_info['cell_list']:
+        for j in i['nbr_list']:
+            if cell_id == j['targetCellId']:
+                return j['pciValue']
+    return None