/**
* @author Ben Edwards (ben@edwards.nz)
* @date 8th December 2016
* @description Controller for the CampaignAddMembersExtCon page
*
**/
public with sharing class CampaignAddMembersExtCon {

    // The Campaign loaded in from the StandardController
    public Campaign theCampaign {get;set;}

    // The list of campaign members for the page
    public List<CampaignMemberWrapper> campaignMembers {get;set;}

    // The Go TO Page selected from the page
    public Integer goToPageNumber {get;set;}

    // CONSTRUCTOR
    public CampaignAddMembersExtCon(ApexPages.StandardController stdController) {

        theCampaign = (Campaign) stdController.getRecord();

        // Load the campaign members for the page
        getCampaignMembersForPage();
    }

    /**
    *   @author Ben Edwards (ben@edwards.nz)
    *   @description StandardSetController to handle pagination for the all campaign members
    *   @return StandardSetController of products
    **/
    public ApexPages.StandardSetController campaignMembersSetCon {

        get {

            if (campaignMembersSetCon == null) {

                // Load all the products into the standard set controller
                campaignMembersSetCon = new ApexPages.StandardSetController(Database.getQueryLocator([
                    SELECT
                        Id
                    FROM
                        CampaignMember
                    WHERE
                        CampaignId = :theCampaign.Id
                ]));

                // Set the page size (defaulted to 20)
                campaignMembersSetCon.setPageSize(20);

                return campaignMembersSetCon;
            }
            return campaignMembersSetCon;
        }
        set;
    }


    /**
    *   @author Ben Edwards (ben@edwards.nz)
    *   @description Store a map of all selected campaign members, so they are included in the save
    *   @return Map of CampaignMember Id
    **/
    public Map<Id, CampaignMemberWrapper> allMembersCached {
        get {
            if (allMembersCached == null) {
                allMembersCached = new Map<Id, CampaignMemberWrapper>();
            }
            return allMembersCached;
        }
        set;
    }


    /**
    *   @author Ben Edwards (ben@edwards.nz)
    *   @description The list of All Products to create
    **/
    public void getCampaignMembersForPage() {

        // Create a new list
        campaignMembers = new List<CampaignMemberWrapper>();

        // Load just the records from the current page
        for (CampaignMember cm :(List<CampaignMember>) campaignMembersSetCon.getRecords()) {

            // If the product already exists in the map
            if (allMembersCached.containsKey(cm.Id)) {

                // Get the cached value from the map
                campaignMembers.add(allMembersCached.get(cm.Id));
            }
            else {

                // Create a new one and default to false
                campaignMembers.add(new CampaignMemberWrapper(cm, false);
            }
        }
    }


    /**
    *   @author Ben Edwards (ben@edwards.nz)
    *   @description When the "next" button is pressed on the pagination
    **/
    public void nextPage() {

        // Update the set of selected products, to cache user's selections
        // across multiple pagess
        updateSelectionMap();

        // Get the next set of values
        campaignMembersSetCon.next();

        // Refresh the products list
        getCampaignMembersForPage();
    }


    /**
    *   @author Ben Edwards (ben@edwards.nz)
    *   @description When the "previous" button is pressed on the pagination
    **/
    public void previousPage() {

        // Update the set of selected products, to cache user's selections
        // across multiple pagess
        updateSelectionMap();

        // Get the next set of values
        campaignMembersSetCon.previous();

        // Refresh the products list
        getCampaignMembersForPage();
    }


    /**
    *   @author Ben Edwards (ben@edwards.nz)
    *   @description Go to a specific page, selected from the page
    **/
    public void goToPage () {

        // Update the set of selected campaign members, to cache user's selections
        // across multiple page
        updateSelectionMap();

        // Get the next set of values
        campaignMembersSetCon.setPageNumber(Integer.valueOf(goToPageNumber));

        // Refresh the products list
        getCampaignMembersForPage();
    }


    /**
    *   @author Ben Edwards (ben@edwards.nz)
    *   @description Updates the set of selected campagin members
    **/
    private void updateSelectionMap () {

        // Iterate over the maps
        for (CampaignMemberWrapper member :campaignMembers) {

            // Store the value back into the map
            allMembersCached.put(member.campaignMember.Id, member);
        }
    }


    /**
    *   @author Ben Edwards (ben@edwards.nz)
    *   @description Save all records and return back to the parent Opportunity
    *   @return Return back to the parent Opportunity
    **/
    public PageReference saveAll () {

        PageReference pageRef;

        // Update the selected All Products before saving
        updateSelectionMap();

        try {

            List<CampaignMember> updateList = new List<CampaignMember>();

            // Iterate over the cached campaign members to do update
            for (CampaignMemberWrapper cmWrapped :allMembersCached) {

                if (cmWrapped.isChecked) {

                    updateList.add(cmWrapped.campaignMember);
                }
            }

            update updateList;
        }
        catch (Exception ex) {

            ApexPages.addMessages(ex);

        }

        return pageRef;
    }



    /**
    *   @description Wrap the CampaignMember into a wrapper class in order to provide checkbox
    **/
    public class CampaignMemberWrapper {

        // Allows the user to check/uncheck the line item from the page
        public Boolean isChecked {get;set;}

        // The various SObject records to create/update
        public CampaignMember  campaignMember {get;set;}

        // Constructor for instantiate an Opp Line
        public LineItemWrapper (CampaignMember member, Boolean checked) {

            this.isChecked = checked;

            // Load the CampaignMember
            this.campaignMember = member;
        }
    }
}