/**
 * Copyright JS Foundation and other contributors, http://js.foundation
 *
 * 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.
 **/
var clone = require("clone");
var redUtil = require("@node-red/util").util;
var Log = require("@node-red/util").log;
var subflowInstanceRE = /^subflow:(.+)$/;
var typeRegistry = require("@node-red/registry");
const credentials = require("../nodes/credentials");

let _runtime = null;

var envVarExcludes = {};

function diffNodes(oldNode,newNode) {
    if (oldNode == null) {
        return true;
    }
    var oldKeys = Object.keys(oldNode).filter(function(p) { return p != "x" && p != "y" && p != "wires" });
    var newKeys = Object.keys(newNode).filter(function(p) { return p != "x" && p != "y" && p != "wires" });
    if (oldKeys.length != newKeys.length) {
        return true;
    }
    for (var i=0;i<newKeys.length;i++) {
        var p = newKeys[i];
        if (!redUtil.compareObjects(oldNode[p],newNode[p])) {
            return true;
        }
    }

    return false;
}

var EnvVarPropertyRE_old = /^\$\((\S+)\)$/;
var EnvVarPropertyRE = /^\${(\S+)}$/;


function mapEnvVarProperties(obj,prop,flow,config) {
    var v = obj[prop];
    if (Buffer.isBuffer(v)) {
        return;
    } else if (Array.isArray(v)) {
        for (var i=0;i<v.length;i++) {
            mapEnvVarProperties(v,i,flow,config);
        }
    } else if (typeof obj[prop] === 'string') {
        if (obj[prop][0] === "$" && (EnvVarPropertyRE_old.test(v) || EnvVarPropertyRE.test(v)) ) {
            var envVar = v.substring(2,v.length-1);
            var r = redUtil.getSetting(config, envVar, flow);
            obj[prop] = r ? r : obj[prop];
        }
    } else {
        for (var p in v) {
            if (v.hasOwnProperty(p)) {
                mapEnvVarProperties(v,p,flow,config);
            }
        }
    }
}

async function evaluateEnvProperties(flow, env, credentials) {
    const pendingEvaluations = []
    const evaluatedEnv = {}
    const envTypes = []
    for (let i = 0; i < env.length; i++) {
        let { name, value, type } = env[i]
        if (type === "env") {
            // Do env types last as they may include references to other env vars
            // at this level which need to be resolved before they can be looked-up
            envTypes.push(env[i])
        } else if (type === "bool") {
            value = (value === "true") || (value === true);
        } else if (type === "cred") {
            if (credentials.hasOwnProperty(name)) {
                value = credentials[name];
            }
        } else if (type ==='jsonata') {
            pendingEvaluations.push(new Promise((resolve, _) => {
                redUtil.evaluateNodeProperty(value, 'jsonata', {_flow: flow}, null, (err, result) => {
                    if (!err) {
                        evaluatedEnv[name] = result
                    }
                    resolve()
                });
            }))
        } else {
            value = redUtil.evaluateNodeProperty(value, type, {_flow: flow}, null, null);
        }
        evaluatedEnv[name] = value
    }
    if (pendingEvaluations.length > 0) {
        await Promise.all(pendingEvaluations)
    }
    for (let i = 0; i < envTypes.length; i++) {
        let { name, value, type } = envTypes[i]
        // If an env-var wants to lookup itself, delegate straight to the parent
        // https://github.com/node-red/node-red/issues/2099
        if (value === name) {
            value = `$parent.${name}`
        }
        if (evaluatedEnv.hasOwnProperty(value)) {
            value = evaluatedEnv[value]
        } else {
            value = redUtil.evaluateNodeProperty(value, type, {_flow: flow}, null, null);
        }
        evaluatedEnv[name] = value
    }

    return evaluatedEnv
}

async function createNode(flow,config) {
    var newNode = null;
    var type = config.type;
    try {
        var nodeTypeConstructor = typeRegistry.get(type);
        if (typeof nodeTypeConstructor === "function") {
            var conf = clone(config);
            delete conf.credentials;
            try {
                Object.defineProperty(conf,'_module', {value: typeRegistry.getNodeInfo(type), enumerable: false, writable: true })
                Object.defineProperty(conf,'_flow', {value: flow, enumerable: false, writable: true })
                Object.defineProperty(conf,'_path', {value: `${flow.path}/${config._alias||config.id}`, enumerable: false, writable: true })

                for (var p in conf) {
                    if (conf.hasOwnProperty(p)) {
                        mapEnvVarProperties(conf,p,flow,conf);
                    }
                }
                newNode = new nodeTypeConstructor(conf);
            } catch (err) {
                Log.log({
                    level: Log.ERROR,
                    id:conf.id,
                    type: type,
                    msg: err
                });
            }
        } else if (nodeTypeConstructor) {
            // console.log(nodeTypeConstructor)
            var subflowConfig = parseConfig([nodeTypeConstructor.subflow].concat(nodeTypeConstructor.subflow.flow));
            var subflowInstanceConfig = subflowConfig.subflows[nodeTypeConstructor.subflow.id];
            delete subflowConfig.subflows[nodeTypeConstructor.subflow.id];
            subflowInstanceConfig.subflows = subflowConfig.subflows;
            var instanceConfig = clone(config);
            instanceConfig.env = clone(nodeTypeConstructor.subflow.env);

            instanceConfig.env = nodeTypeConstructor.subflow.env.map(nodeProp => {
                var nodePropType;
                var nodePropValue = config[nodeProp.name];
                if (nodeProp.type === "cred") {
                    nodePropType = "cred";
                } else {
                    switch(typeof config[nodeProp.name]) {
                        case "string": nodePropType = "str"; break;
                        case "number": nodePropType = "num"; break;
                        case "boolean": nodePropType = "bool"; nodePropValue == nodeProp?"true":"false"; break;
                        default:
                            nodePropType = config[nodeProp.name].type;
                            nodePropValue = config[nodeProp.name].value;
                    }
                }
                return {
                    name: nodeProp.name,
                    type: nodePropType,
                    value: nodePropValue
                }
            })

            var subflow = require("./Subflow").createModuleInstance(
                nodeTypeConstructor.type,
                flow,
                flow.global,
                subflowInstanceConfig,
                instanceConfig
            );
            // Register this subflow as an instance node of the parent flow.
            // This allows nodes inside the subflow to get ahold of each other
            // such as a node accessing its config node
            flow.subflowInstanceNodes[config.id] = subflow
            await subflow.start();
            return subflow.node;
        }
    } catch(err) {
        Log.error(err);
    }
    return newNode;
}

function parseConfig(config) {
    var flow = {};
    flow.allNodes = {};
    flow.subflows = {};
    flow.configs = {};
    flow.flows = {};
    flow.missingTypes = [];

    config.forEach(function (n) {
        flow.allNodes[n.id] = clone(n);
        if (n.type === 'tab') {
            flow.flows[n.id] = n;
            flow.flows[n.id].subflows = {};
            flow.flows[n.id].configs = {};
            flow.flows[n.id].nodes = {};
            flow.flows[n.id].groups = {};
        } else if (n.type === 'subflow') {
            flow.subflows[n.id] = n;
            flow.subflows[n.id].configs = {};
            flow.subflows[n.id].nodes = {};
            flow.subflows[n.id].groups = {};
            flow.subflows[n.id].instances = [];
        }
    });

    var linkWires = {};
    var linkOutNodes = [];
    config.forEach(function (n) {
        if (n.type !== 'subflow' && n.type !== 'tab' && n.type !== 'group') {
            var subflowDetails = subflowInstanceRE.exec(n.type);

            if ((subflowDetails && !flow.subflows[subflowDetails[1]]) || (!subflowDetails && !typeRegistry.get(n.type))) {
                if (flow.missingTypes.indexOf(n.type) === -1) {
                    flow.missingTypes.push(n.type);
                }
            }
            var container = null;
            if (flow.flows[n.z]) {
                container = flow.flows[n.z];
            } else if (flow.subflows[n.z]) {
                container = flow.subflows[n.z];
            }
            if (n.hasOwnProperty('x') && n.hasOwnProperty('y')) {
                if (subflowDetails) {
                    var subflowType = subflowDetails[1]
                    n.subflow = subflowType;
                    if (flow.subflows[subflowType]) {
                        flow.subflows[subflowType].instances.push(n)
                    }
                }
                if (container) {
                    container.nodes[n.id] = n;
                }
            } else {
                if (container) {
                    container.configs[n.id] = n;
                } else {
                    flow.configs[n.id] = n;
                    flow.configs[n.id]._users = [];
                }
            }
            if (n.type === 'link in' && n.links) {
                // Ensure wires are present in corresponding link out nodes
                n.links.forEach(function (id) {
                    linkWires[id] = linkWires[id] || {};
                    linkWires[id][n.id] = true;
                })
            } else if (n.type === 'link out' && n.links) {
                linkWires[n.id] = linkWires[n.id] || {};
                n.links.forEach(function (id) {
                    linkWires[n.id][id] = true;
                })
                linkOutNodes.push(n);
            }
        } else if (n.type === 'group') {
            const parentContainer = flow.flows[n.z] || flow.subflows[n.z]
            if (parentContainer) {
                parentContainer.groups[n.id] = n
            }
        }
    });
    linkOutNodes.forEach(function (n) {
        var links = linkWires[n.id];
        var targets = Object.keys(links);
        n.wires = [targets];
    });


    var addedTabs = {};
    config.forEach(function (n) {
        if (n.type !== 'subflow' && n.type !== 'tab' && n.type !== 'group') {
            for (var prop in n) {
                if (n.hasOwnProperty(prop) && prop !== 'id' && prop !== 'wires' && prop !== 'type' && prop !== '_users' && flow.configs.hasOwnProperty(n[prop])) {
                    // This property references a global config node
                    flow.configs[n[prop]]._users.push(n.id)
                }
            }
            if (n.z && !flow.subflows[n.z]) {

                if (!flow.flows[n.z]) {
                    flow.flows[n.z] = { type: 'tab', id: n.z };
                    flow.flows[n.z].subflows = {};
                    flow.flows[n.z].configs = {};
                    flow.flows[n.z].nodes = {};
                    addedTabs[n.z] = flow.flows[n.z];
                }
                if (addedTabs[n.z]) {
                    if (n.hasOwnProperty('x') && n.hasOwnProperty('y')) {
                        addedTabs[n.z].nodes[n.id] = n;
                    } else {
                        addedTabs[n.z].configs[n.id] = n;
                    }
                }
            }
        }
    });
    return flow;
}

function getGlobalEnv(name) {
    const nodes = _runtime.nodes;
    if (!nodes) {
        return null;
    }
    const gconf = nodes.getGlobalConfig();
    const env = gconf ? gconf.env : null;

    if (env) {
        const cred = (gconf ? credentials.get(gconf.id) : null) || {
            map: {}
        };
        const map = cred.map;

        for (let i = 0; i < env.length; i++) {
            const item = env[i];
            if (item.name === name) {
                if (item.type === "cred") {
                    return {
                        name: name,
                        value: map[name],
                        type: "cred"
                    };
                }
                return item;
            }
        }
    }
    return null;
}

module.exports = {
    init: function(runtime) {
        _runtime = runtime;
        envVarExcludes = {};
        if (runtime.settings.hasOwnProperty('envVarExcludes') && Array.isArray(runtime.settings.envVarExcludes)) {
            runtime.settings.envVarExcludes.forEach(v => envVarExcludes[v] = true);
        }
    },
    getEnvVar: function(k) {
        if (!envVarExcludes[k]) {
            const item = getGlobalEnv(k);
            if (item) {
                const val = redUtil.evaluateNodeProperty(item.value, item.type, null, null, null);
                return val;
            }
            return process.env[k];
        }
        return undefined;
    },

    diffNodes,
    mapEnvVarProperties,
    evaluateEnvProperties,
    parseConfig,

    diffConfigs: function(oldConfig, newConfig) {
        var id;
        var node;
        var nn;
        var wires;
        var j,k;

        if (!oldConfig) {
            oldConfig = {
                flows:{},
                allNodes:{}
            }
        }
        var changedSubflows = {};

        var added = {};
        var removed = {};
        var changed = {};
        var wiringChanged = {};

        var linkMap = {};

        var changedTabs = {};

        // Look for tabs that have been removed
        for (id in oldConfig.flows) {
            if (oldConfig.flows.hasOwnProperty(id) && (!newConfig.flows.hasOwnProperty(id))) {
                removed[id] = oldConfig.allNodes[id];
            }
        }

        // Look for tabs that have been disabled
        for (id in oldConfig.flows) {
            if (oldConfig.flows.hasOwnProperty(id) && newConfig.flows.hasOwnProperty(id)) {
                var originalState = oldConfig.flows[id].disabled||false;
                var newState = newConfig.flows[id].disabled||false;
                if (originalState !== newState) {
                    changedTabs[id] = true;
                    if (originalState) {
                        added[id] = oldConfig.allNodes[id];
                    } else {
                        removed[id] = oldConfig.allNodes[id];
                    }
                }
            }
        }

        for (id in oldConfig.allNodes) {
            if (oldConfig.allNodes.hasOwnProperty(id)) {
                node = oldConfig.allNodes[id];
                if (node.type !== 'tab') {
                    // build the map of what this node was previously wired to
                    if (node.wires) {
                        linkMap[node.id] = linkMap[node.id] || [];
                        for (j=0;j<node.wires.length;j++) {
                            wires = node.wires[j];
                            for (k=0;k<wires.length;k++) {
                                linkMap[node.id].push(wires[k]);
                                nn = oldConfig.allNodes[wires[k]];
                                if (nn) {
                                    linkMap[nn.id] = linkMap[nn.id] || [];
                                    linkMap[nn.id].push(node.id);
                                }
                            }
                        }
                    }
                    // This node has been removed or its flow disabled
                    if (removed[node.z] || !newConfig.allNodes.hasOwnProperty(id)) {
                        removed[id] = node;
                        // Mark the container as changed
                        if (!removed[node.z] && newConfig.allNodes[removed[id].z]) {
                            changed[removed[id].z] = newConfig.allNodes[removed[id].z];
                            if (changed[removed[id].z].type === "subflow") {
                                changedSubflows[removed[id].z] = changed[removed[id].z];
                                //delete removed[id];
                            }
                        }
                    } else {
                        if (added[node.z]) {
                            added[id] = node;
                        } else {
                            var currentState = node.d;
                            var newState = newConfig.allNodes[id].d;
                            if (!currentState && newState) {
                                removed[id] = node;
                            }
                            // This node has a material configuration change
                            if (diffNodes(node,newConfig.allNodes[id]) || newConfig.allNodes[id].credentials) {
                                changed[id] = newConfig.allNodes[id];
                                if (changed[id].type === "subflow") {
                                    changedSubflows[id] = changed[id];
                                }
                                // Mark the container as changed
                                if (newConfig.allNodes[changed[id].z]) {
                                    changed[changed[id].z] = newConfig.allNodes[changed[id].z];
                                    if (changed[changed[id].z].type === "subflow") {
                                        changedSubflows[changed[id].z] = changed[changed[id].z];
                                        delete changed[id];
                                    }
                                }
                            }
                            // This node's wiring has changed
                            if (!redUtil.compareObjects(node.wires,newConfig.allNodes[id].wires)) {
                                wiringChanged[id] = newConfig.allNodes[id];
                                // Mark the container as changed
                                if (newConfig.allNodes[wiringChanged[id].z]) {
                                    changed[wiringChanged[id].z] = newConfig.allNodes[wiringChanged[id].z];
                                    if (changed[wiringChanged[id].z].type === "subflow") {
                                        changedSubflows[wiringChanged[id].z] = changed[wiringChanged[id].z];
                                        delete wiringChanged[id];
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
        // Look for added nodes
        for (id in newConfig.allNodes) {
            if (newConfig.allNodes.hasOwnProperty(id)) {
                node = newConfig.allNodes[id];
                // build the map of what this node is now wired to
                if (node.wires) {
                    linkMap[node.id] = linkMap[node.id] || [];
                    for (j=0;j<node.wires.length;j++) {
                        wires = node.wires[j];
                        for (k=0;k<wires.length;k++) {
                            if (linkMap[node.id].indexOf(wires[k]) === -1) {
                                linkMap[node.id].push(wires[k]);
                            }
                            nn = newConfig.allNodes[wires[k]];
                            if (nn) {
                                linkMap[nn.id] = linkMap[nn.id] || [];
                                if (linkMap[nn.id].indexOf(node.id) === -1) {
                                    linkMap[nn.id].push(node.id);
                                }
                            }
                        }
                    }
                }
                // This node has been added
                if (!oldConfig.allNodes.hasOwnProperty(id)) {
                    added[id] = node;
                    // Mark the container as changed
                    if (newConfig.allNodes[added[id].z]) {
                        changed[added[id].z] = newConfig.allNodes[added[id].z];
                        if (changed[added[id].z].type === "subflow") {
                            changedSubflows[added[id].z] = changed[added[id].z];
                            delete added[id];
                        }
                    }
                }
            }
        }

        var madeChange;
        // Loop through the nodes looking for references to changed config nodes
        // Repeat the loop if anything is marked as changed as it may need to be
        // propagated to parent nodes.
        // TODO: looping through all nodes every time is a bit inefficient - could be more targeted
        do {
            madeChange = false;
            for (id in newConfig.allNodes) {
                if (newConfig.allNodes.hasOwnProperty(id)) {
                    node = newConfig.allNodes[id];
                    for (var prop in node) {
                        if (node.hasOwnProperty(prop) && prop != "z" && prop != "id" && prop != "wires") {
                            // This node has a property that references a changed/removed node
                            // Assume it is a config node change and mark this node as
                            // changed.

                            var changeOrigin = changed[node[prop]];
                            if (changeOrigin || removed[node[prop]]) {
                                if (!changed[node.id]) {
                                    if (changeOrigin &&
                                        (prop === "g") &&
                                        (changeOrigin.type === "group")) {
                                        var oldNode = oldConfig.allNodes[node.id];
                                        // ignore change of group node
                                        // if group of this node not changed
                                        if (oldNode &&
                                            (node.g === oldNode.g)) {
                                            continue;
                                        }
                                    }
                                    madeChange = true;
                                    changed[node.id] = node;
                                    // This node exists within subflow template
                                    // Mark the template as having changed
                                    if (newConfig.allNodes[node.z]) {
                                        changed[node.z] = newConfig.allNodes[node.z];
                                        if (changed[node.z].type === "subflow") {
                                            changedSubflows[node.z] = changed[node.z];
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
        } while (madeChange===true)

        // Find any nodes that exist on a subflow template and remove from changed
        // list as the parent subflow will now be marked as containing a change
        for (id in newConfig.allNodes) {
            if (newConfig.allNodes.hasOwnProperty(id)) {
                node = newConfig.allNodes[id];
                if (newConfig.allNodes[node.z] && newConfig.allNodes[node.z].type === "subflow") {
                    delete changed[node.id];
                }
            }
        }

        // Recursively mark all instances of changed subflows as changed
        var changedSubflowStack = Object.keys(changedSubflows);
        while (changedSubflowStack.length > 0) {
            var subflowId = changedSubflowStack.pop();
            for (id in newConfig.allNodes) {
                if (newConfig.allNodes.hasOwnProperty(id)) {
                    node = newConfig.allNodes[id];
                    if (node.type === 'subflow:'+subflowId) {
                        if (!changed[node.id]) {
                            changed[node.id] = node;
                            if (!changed[changed[node.id].z] && newConfig.allNodes[changed[node.id].z]) {
                                changed[changed[node.id].z] = newConfig.allNodes[changed[node.id].z];
                                if (newConfig.allNodes[changed[node.id].z].type === "subflow") {
                                    // This subflow instance is inside a subflow. Add the
                                    // containing subflow to the stack to mark
                                    changedSubflowStack.push(changed[node.id].z);
                                    delete changed[node.id];
                                }
                            }
                        }
                    }
                }
            }
        }

        var diff = {
            added:Object.keys(added),
            changed:Object.keys(changed),
            removed:Object.keys(removed),
            rewired:Object.keys(wiringChanged),
            linked:[]
        }

        // Traverse the links of all modified nodes to mark the connected nodes
        var modifiedNodes = diff.added.concat(diff.changed).concat(diff.removed).concat(diff.rewired);
        var visited = {};
        while (modifiedNodes.length > 0) {
            node = modifiedNodes.pop();
            if (!visited[node]) {
                visited[node] = true;
                if (linkMap[node]) {
                    if (!changed[node] && !added[node] && !removed[node] && !wiringChanged[node]) {
                        diff.linked.push(node);
                    }
                    modifiedNodes = modifiedNodes.concat(linkMap[node]);
                }
            }
        }
        // console.log(diff);
        // for (id in newConfig.allNodes) {
        //     console.log(
        //         (added[id]?"a":(changed[id]?"c":" "))+(wiringChanged[id]?"w":" ")+(diff.linked.indexOf(id)!==-1?"l":" "),
        //         newConfig.allNodes[id].type.padEnd(10),
        //         id.padEnd(16),
        //         (newConfig.allNodes[id].z||"").padEnd(16),
        //         newConfig.allNodes[id].name||newConfig.allNodes[id].label||""
        //     );
        // }
        // for (id in removed) {
        //     console.log(
        //         "- "+(diff.linked.indexOf(id)!==-1?"~":" "),
        //         id,
        //         oldConfig.allNodes[id].type,
        //         oldConfig.allNodes[id].name||oldConfig.allNodes[id].label||""
        //     );
        // }

        return diff;
    },

    /**
     * Create a new instance of a node
     * @param  {Flow} flow     The containing flow
     * @param  {object} config The node configuration object
     * @return {Node}          The instance of the node
     */
    createNode: createNode,
    evaluateEnvProperties
}