package com.fsck.k9.helper;

import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.content.Intent;
import android.provider.ContactsContract;
import android.util.Log;

import com.fsck.k9.K9;
import com.fsck.k9.mail.Address;

import java.util.ArrayList;

/**
 * Helper class to access the contacts stored on the device.
 */
public class Contacts {
    /**
     * The order in which the search results are returned by
     * {@link #searchContacts(CharSequence)}.
     */
    protected static final String SORT_ORDER =
            ContactsContract.CommonDataKinds.Email.TIMES_CONTACTED + " DESC, " +
                    ContactsContract.Contacts.DISPLAY_NAME + ", " +
                    ContactsContract.CommonDataKinds.Email._ID;

    /**
     * Array of columns to load from the database.
     *
     * Important: The _ID field is needed by
     * {@link com.fsck.k9.EmailAddressAdapter} or more specificly by
     * {@link android.widget.ResourceCursorAdapter}.
     */
    protected static final String PROJECTION[] = {
            ContactsContract.CommonDataKinds.Email._ID,
            ContactsContract.Contacts.DISPLAY_NAME,
            ContactsContract.CommonDataKinds.Email.DATA,
            ContactsContract.CommonDataKinds.Email.CONTACT_ID
    };

    /**
     * Index of the name field in the projection. This must match the order in
     * {@link #PROJECTION}.
     */
    protected static final int NAME_INDEX = 1;

    /**
     * Index of the email address field in the projection. This must match the
     * order in {@link #PROJECTION}.
     */
    protected static final int EMAIL_INDEX = 2;

    /**
     * Index of the contact id field in the projection. This must match the order in
     * {@link #PROJECTION}.
     */
    protected static final int CONTACT_ID_INDEX = 3;


    /**
     * Get instance of the Contacts class.
     *
     * <p>Note: This is left over from the days when we needed to have SDK-specific code to access
     * the contacts.</p>
     *
     * @param context A {@link Context} instance.
     * @return Appropriate {@link Contacts} instance for this device.
     */
    public static Contacts getInstance(Context context) {
        return new Contacts(context);
    }


    protected Context mContext;
    protected ContentResolver mContentResolver;
    protected Boolean mHasContactPicker;

    /**
     * Constructor
     *
     * @param context A {@link Context} instance.
     */
    protected Contacts(Context context) {
        mContext = context;
        mContentResolver = context.getContentResolver();
    }

    /**
     * Start the activity to add information to an existing contact or add a
     * new one.
     *
     * @param email An {@link Address} instance containing the email address
     *              of the entity you want to add to the contacts. Optionally
     *              the instance also contains the (display) name of that
     *              entity.
     */
    public void createContact(final Address email) {
        final Uri contactUri = Uri.fromParts("mailto", email.getAddress(), null);

        final Intent contactIntent = new Intent(ContactsContract.Intents.SHOW_OR_CREATE_CONTACT);
        contactIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        contactIntent.setData(contactUri);

        // Pass along full E-mail string for possible create dialog
        contactIntent.putExtra(ContactsContract.Intents.EXTRA_CREATE_DESCRIPTION,
                email.toString());

        // Only provide personal name hint if we have one
        final String senderPersonal = email.getPersonal();
        if (senderPersonal != null) {
            contactIntent.putExtra(ContactsContract.Intents.Insert.NAME, senderPersonal);
        }

        mContext.startActivity(contactIntent);
    }

    /**
     * Start the activity to add a phone number to an existing contact or add a new one.
     *
     * @param phoneNumber
     *         The phone number to add to a contact, or to use when creating a new contact.
     */
    public void addPhoneContact(final String phoneNumber) {
        Intent addIntent = new Intent(Intent.ACTION_INSERT_OR_EDIT);
        addIntent.setType(ContactsContract.Contacts.CONTENT_ITEM_TYPE);
        addIntent.putExtra(ContactsContract.Intents.Insert.PHONE, Uri.decode(phoneNumber));
        addIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        mContext.startActivity(addIntent);
    }

    /**
     * Check whether the provided email address belongs to one of the contacts.
     *
     * @param emailAddress The email address to look for.
     * @return <tt>true</tt>, if the email address belongs to a contact.
     *         <tt>false</tt>, otherwise.
     */
    public boolean isInContacts(final String emailAddress) {
        boolean result = false;

        final Cursor c = getContactByAddress(emailAddress);

        if (c != null) {
            if (c.getCount() > 0) {
                result = true;
            }
            c.close();
        }

        return result;
    }

    /**
     * Filter the contacts matching the given search term.
     *
     * @param constraint The search term to filter the contacts.
     * @return A {@link Cursor} instance that can be used to get the
     *         matching contacts.
     */
    public Cursor searchContacts(final CharSequence constraint) {
        final String filter = (constraint == null) ? "" : constraint.toString();
        final Uri uri = Uri.withAppendedPath(ContactsContract.CommonDataKinds.Email.CONTENT_FILTER_URI, Uri.encode(filter));
        final Cursor c = mContentResolver.query(
                uri,
                PROJECTION,
                null,
                null,
                SORT_ORDER);

        if (c != null) {
            /*
             * To prevent expensive execution in the UI thread:
             * Cursors get lazily executed, so if you don't call anything on
             * the cursor before returning it from the background thread you'll
             * have a complied program for the cursor, but it won't have been
             * executed to generate the data yet. Often the execution is more
             * expensive than the compilation...
             */
            c.getCount();
        }

        return c;
    }

    /**
     * Get the name of the contact an email address belongs to.
     *
     * @param address The email address to search for.
     * @return The name of the contact the email address belongs to. Or
     *      <tt>null</tt> if there's no matching contact.
     */
    public String getNameForAddress(String address) {
        if (address == null) {
            return null;
        }

        final Cursor c = getContactByAddress(address);

        String name = null;
        if (c != null) {
            if (c.getCount() > 0) {
                c.moveToFirst();
                name = getName(c);
            }
            c.close();
        }

        return name;
    }

    /**
     * Extract the name from a {@link Cursor} instance returned by
     * {@link #searchContacts(CharSequence)}.
     *
     * @param cursor The {@link Cursor} instance.
     * @return The name of the contact in the {@link Cursor}'s current row.
     */
    public String getName(Cursor cursor) {
        return cursor.getString(NAME_INDEX);
    }

    /**
     * Extract the email address from a {@link Cursor} instance returned by
     * {@link #searchContacts(CharSequence)}.
     *
     * @param cursor The {@link Cursor} instance.
     * @return The email address of the contact in the {@link Cursor}'s current
     *         row.
     */
    public String getEmail(Cursor cursor) {
        return cursor.getString(EMAIL_INDEX);
    }

    /**
     * Mark contacts with the provided email addresses as contacted.
     *
     * @param addresses Array of {@link Address} objects describing the
     *        contacts to be marked as contacted.
     */
    public void markAsContacted(final Address[] addresses) {
        //TODO: Optimize! Potentially a lot of database queries
        for (final Address address : addresses) {
            final Cursor c = getContactByAddress(address.getAddress());

            if (c != null) {
                if (c.getCount() > 0) {
                    c.moveToFirst();
                    final long personId = c.getLong(CONTACT_ID_INDEX);
                    ContactsContract.Contacts.markAsContacted(mContentResolver, personId);
                }
                c.close();
            }
        }
    }

    /**
     * Creates the intent necessary to open a contact picker.
     *
     * @return The intent necessary to open a contact picker.
     */
    public Intent contactPickerIntent() {
        return new Intent(Intent.ACTION_PICK, ContactsContract.Contacts.CONTENT_URI);
    }

    /**
     * Given a contact picker intent, returns a {@code ContactItem} instance for that contact.
     *
     * @param intent
     *         The {@link Intent} returned by the contact picker.
     *
     * @return A {@link ContactItem} instance describing the picked contact. Or {@code null} if the
     *         contact doesn't have any email addresses.
     */
    public ContactItem extractInfoFromContactPickerIntent(final Intent intent) {
        Cursor cursor = null;
        ArrayList<String> email = new ArrayList<String>();

        try {
            Uri result = intent.getData();
            String displayName = null;

            // Get the contact id from the Uri
            String id = result.getLastPathSegment();

            cursor = mContentResolver.query(ContactsContract.CommonDataKinds.Email.CONTENT_URI, PROJECTION,
                    ContactsContract.CommonDataKinds.Email.CONTACT_ID + "=?", new String[] { id }, null);

            if (cursor != null) {
                while (cursor.moveToNext()) {
                    String address = cursor.getString(EMAIL_INDEX);
                    if (address != null) {
                        email.add(address);
                    }

                    if (displayName == null) {
                        displayName = cursor.getString(NAME_INDEX);
                    }
                }

                // Return 'null' if no email addresses have been found
                if (email.size() == 0) {
                    return null;
                }

                // Use the first email address found as display name
                if (displayName == null) {
                    displayName = email.get(0);
                }

                return new ContactItem(displayName, email);
            }
        } catch (Exception e) {
            Log.e(K9.LOG_TAG, "Failed to get email data", e);
        } finally {
            Utility.closeQuietly(cursor);
        }

        return null;
    }

    /**
     * Get URI to the picture of the contact with the supplied email address.
     *
     * @param address
     *         An email address. The contact database is searched for a contact with this email
     *         address.
     *
     * @return URI to the picture of the contact with the supplied email address. {@code null} if
     *         no such contact could be found or the contact doesn't have a picture.
     */
    public Uri getPhotoUri(String address) {
        Long contactId;
        try {
            final Cursor c = getContactByAddress(address);
            if (c == null) {
                return null;
            }

            try {
                if (!c.moveToFirst()) {
                    return null;
                }

                contactId = c.getLong(CONTACT_ID_INDEX);
            } finally {
                c.close();
            }

            Cursor cur = mContentResolver.query(
                    ContactsContract.Data.CONTENT_URI,
                    null,
                    ContactsContract.Data.CONTACT_ID + "=" + contactId + " AND "
                            + ContactsContract.Data.MIMETYPE + "='"
                            + ContactsContract.CommonDataKinds.Photo.CONTENT_ITEM_TYPE + "'", null,
                    null);
            if (cur == null) {
                return null;
            }
            if (!cur.moveToFirst()) {
                cur.close();
                return null; // no photo
            }
            // Ok, they have a photo
            cur.close();
            Uri person = ContentUris.withAppendedId(ContactsContract.Contacts.CONTENT_URI, contactId);
            return Uri.withAppendedPath(person, ContactsContract.Contacts.Photo.CONTENT_DIRECTORY);
        } catch (Exception e) {
            Log.e(K9.LOG_TAG, "Couldn't fetch photo for contact with email " + address, e);
            return null;
        }
    }

    /**
     * Does the device actually have a Contacts application suitable for
     * picking a contact. As hard as it is to believe, some vendors ship
     * without it.
     *
     * @return True, if the device supports picking contacts. False, otherwise.
     */
    public boolean hasContactPicker() {
        if (mHasContactPicker == null) {
            mHasContactPicker = !(mContext.getPackageManager().
                                  queryIntentActivities(contactPickerIntent(), 0).isEmpty());
        }
        return mHasContactPicker;
    }

    /**
     * Return a {@link Cursor} instance that can be used to fetch information
     * about the contact with the given email address.
     *
     * @param address The email address to search for.
     * @return A {@link Cursor} instance that can be used to fetch information
     *         about the contact with the given email address
     */
    private Cursor getContactByAddress(final String address) {
        final Uri uri = Uri.withAppendedPath(ContactsContract.CommonDataKinds.Email.CONTENT_LOOKUP_URI, Uri.encode(address));
        final Cursor c = mContentResolver.query(
                uri,
                PROJECTION,
                null,
                null,
                SORT_ORDER);
        return c;
    }

}