package com.example.sprite.half_lifetimer;

import android.content.Intent;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.lang.reflect.Array;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.List;

import static android.support.v4.content.FileProvider.getUriForFile;

public class ExportDatabase extends AppCompatActivity {

    boolean prettyPrinting = false;
    String usagesFN = "usages.json";
    String substancesFN = "substances.json";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_export_database);

        updateDisplay();
    }

    private void updateDisplay() {
        LinearLayout lloJSONtxt = findViewById(R.id.lloDBDump);
        LinearLayout lloDumpStats = findViewById(R.id.lloDumpStats);
        TextView tvwJSON = new TextView(this);
        TextView tvwDumpStats = new TextView(this);

        tvwJSON.setText(generateJSON());
        lloJSONtxt.removeAllViewsInLayout();
        lloJSONtxt.addView(tvwJSON);

        tvwDumpStats.setText(
                getResources().getString(R.string.json_resides_in, this.getFilesDir()));
        lloDumpStats.removeAllViewsInLayout();
        lloDumpStats.addView(tvwDumpStats);
    }

    private String generateJSON() {
        Gson gson;
        List<Usage> allUsages = Permanence.loadUsages();
        List<Substance> allSubstances = Permanence.loadSubstances(this);
        String substancesJSON;
        String usagesJSON;

        if (prettyPrinting) {
            gson = new GsonBuilder().setPrettyPrinting().create();
        } else {
            gson = new Gson();
        }
        substancesJSON = gson.toJson(allSubstances);
        usagesJSON = gson.toJson(allUsages);

        try {
            File usagesFile = new File(this.getFilesDir(), usagesFN);
            File substancesFile = new File(this.getFilesDir(), substancesFN);
            FileOutputStream usagesIS = new FileOutputStream(usagesFile);
            FileOutputStream substancesIS = new FileOutputStream(substancesFile);
            OutputStreamWriter usagesOSW = new OutputStreamWriter(usagesIS);
            OutputStreamWriter substancesOSW = new OutputStreamWriter(substancesIS);
            Writer usagesW = new BufferedWriter(usagesOSW);
            Writer substancesW = new BufferedWriter(substancesOSW);

            usagesW.write(usagesJSON);
            substancesW.write(substancesJSON);
            usagesW.close();
            substancesW.close();
        } catch (FileNotFoundException ex) {
            GlobalMisc.showSimpleDialog(this, "Exception", "File not found " +
                    "exception!\n" + ex.toString());
        } catch (IOException ex) {
            GlobalMisc.showSimpleDialog(this, "Exception", "Input/Output " +
                    "exception!\n" + ex.toString());
        }

        return "Substances JSON\n\n" + substancesJSON + "\n\nUsages JSON\n\n" + usagesJSON;
    }

    public void togglePretty(View v) {
        prettyPrinting = !prettyPrinting;

        updateDisplay();
    }

    public void shareJSON(View v) {
        File filesDirPath = new File(getFilesDir(), "files");
        filesDirPath.mkdirs();
        File usagesFile = new File(filesDirPath, usagesFN);
        File substancesFile = new File(this.getFilesDir(), substancesFN);
        Uri usagesUri = getUriForFile(this, "com.example.sprite.fileprovider", usagesFile);
        /*Uri substancesUri = getUriForFile(this, "com.example.sprite.half_lifetimer.fileprovider",
                substancesFile);*/

        Intent intentShareJSON = new Intent(Intent.ACTION_SEND);

        //intentShareJSON.setType(URLConnection.guessContentTypeFromName(usagesFN));
        intentShareJSON.setType("text/plain");
        /*intentShareJSON.putExtra(Intent.EXTRA_STREAM, Uri.parse("content://" + this.getFilesDir() +
                "/" + usagesFN));*/
        //intentShareJSON.setData(usagesUri);
        intentShareJSON.putExtra(Intent.EXTRA_STREAM, usagesUri);

        startActivity(Intent.createChooser(intentShareJSON, "Share JSON"));
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.sprite.half_lifetimer">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".ExportDatabase"></activity>
        <activity android:name=".ConsolidateDatabase" />
        <activity android:name=".DailyStats" />
        <activity android:name=".DatabaseMaint" />
        <activity android:name=".SubClassTabbedData" />
        <activity
            android:name=".SubClass"
            android:label="@string/title_activity_sub_class"
            android:theme="@style/AppTheme.NoActionBar" />
        <activity android:name=".DosageGraphing" />
        <activity android:name=".UsualSuspects" />
        <activity android:name=".AddPastUsage" />
        <activity android:name=".SubsRankedByLastUsage" />
        <activity android:name=".FullAdminsDumpByID" />
        <activity android:name=".FullAdminsDump" />
        <activity android:name=".TabbedData" />
        <activity android:name=".AdminData" />
        <activity
            android:name=".SubData"
            android:label="@string/app_name"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="com.example.provider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/file_paths">
            </meta-data>
        </provider>

    </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <files-path name="files" path="files/" />
</paths>