package org.thoughtcrime.securesms.groups

import android.content.Context
import android.content.Intent
import android.os.Bundle
import android.view.Menu
import android.view.MenuItem
import android.view.View
import android.view.inputmethod.EditorInfo
import android.view.inputmethod.InputMethodManager
import android.widget.EditText
import android.widget.LinearLayout
import android.widget.TextView
import android.widget.Toast
import androidx.loader.app.LoaderManager
import androidx.loader.content.Loader
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import dagger.hilt.android.AndroidEntryPoint
import network.loki.messenger.R
import nl.komponents.kovenant.Promise
import nl.komponents.kovenant.task
import nl.komponents.kovenant.ui.failUi
import nl.komponents.kovenant.ui.successUi
import org.session.libsession.messaging.sending_receiving.MessageSender
import org.session.libsession.messaging.sending_receiving.groupSizeLimit
import org.session.libsession.utilities.Address
import org.session.libsession.utilities.GroupUtil
import org.session.libsession.utilities.TextSecurePreferences
import org.session.libsession.utilities.ThemeUtil
import org.session.libsession.utilities.recipients.Recipient
import org.session.libsignal.utilities.Log
import org.session.libsignal.utilities.toHexString
import org.thoughtcrime.securesms.PassphraseRequiredActionBarActivity
import org.thoughtcrime.securesms.contacts.SelectContactsActivity
import org.thoughtcrime.securesms.database.Storage
import org.thoughtcrime.securesms.dependencies.ConfigFactory
import org.thoughtcrime.securesms.dependencies.DatabaseComponent
import org.thoughtcrime.securesms.groups.ClosedGroupManager.updateLegacyGroup
import org.thoughtcrime.securesms.mms.GlideApp
import org.thoughtcrime.securesms.util.fadeIn
import org.thoughtcrime.securesms.util.fadeOut
import java.io.IOException
import javax.inject.Inject

@AndroidEntryPoint
class EditLegacyClosedGroupActivity : PassphraseRequiredActionBarActivity() {

    @Inject
    lateinit var groupConfigFactory: ConfigFactory
    @Inject
    lateinit var storage: Storage

    private val originalMembers = HashSet<String>()
    private val zombies = HashSet<String>()
    private val members = HashSet<String>()
    private val allMembers: Set<String>
        get() {
            return members + zombies
        }
    private var hasNameChanged = false
    private var isSelfAdmin = false
    private var isLoading = false
        set(newValue) { field = newValue; invalidateOptionsMenu() }

    private lateinit var groupID: String
    private lateinit var originalName: String
    private lateinit var name: String

    private var isEditingName = false
        set(value) {
            if (field == value) return
            field = value
            handleIsEditingNameChanged()
        }

    private val memberListAdapter by lazy {
        if (isSelfAdmin)
            EditClosedGroupMembersAdapter(this, GlideApp.with(this), isSelfAdmin, this::onMemberClick)
        else
            EditClosedGroupMembersAdapter(this, GlideApp.with(this), isSelfAdmin)
    }

    private lateinit var mainContentContainer: LinearLayout
    private lateinit var cntGroupNameEdit: LinearLayout
    private lateinit var cntGroupNameDisplay: LinearLayout
    private lateinit var edtGroupName: EditText
    private lateinit var emptyStateContainer: LinearLayout
    private lateinit var lblGroupNameDisplay: TextView
    private lateinit var loaderContainer: View

    companion object {
        @JvmStatic val groupIDKey = "groupIDKey"
        private val loaderID = 0
        val addUsersRequestCode = 124
        val legacyGroupSizeLimit = 10
    }

    // region Lifecycle
    override fun onCreate(savedInstanceState: Bundle?, isReady: Boolean) {
        super.onCreate(savedInstanceState, isReady)
        setContentView(R.layout.activity_edit_closed_group)

        supportActionBar!!.setHomeAsUpIndicator(
                ThemeUtil.getThemedDrawableResId(this, R.attr.actionModeCloseDrawable))

        groupID = intent.getStringExtra(groupIDKey)!!
        val groupInfo = DatabaseComponent.get(this).groupDatabase().getGroup(groupID).get()
        originalName = groupInfo.title
        isSelfAdmin = groupInfo.admins.any{ it.serialize() == TextSecurePreferences.getLocalNumber(this) }

        name = originalName

        mainContentContainer = findViewById(R.id.mainContentContainer)
        cntGroupNameEdit = findViewById(R.id.cntGroupNameEdit)
        cntGroupNameDisplay = findViewById(R.id.cntGroupNameDisplay)
        edtGroupName = findViewById(R.id.edtGroupName)
        emptyStateContainer = findViewById(R.id.emptyStateContainer)
        lblGroupNameDisplay = findViewById(R.id.lblGroupNameDisplay)
        loaderContainer = findViewById(R.id.loaderContainer)

        findViewById<View>(R.id.addMembersClosedGroupButton).setOnClickListener {
            onAddMembersClick()
        }

        findViewById<RecyclerView>(R.id.rvUserList).apply {
            adapter = memberListAdapter
            layoutManager = LinearLayoutManager(this@EditLegacyClosedGroupActivity)
        }

        lblGroupNameDisplay.text = originalName
        cntGroupNameDisplay.setOnClickListener { isEditingName = true }
        findViewById<View>(R.id.btnCancelGroupNameEdit).setOnClickListener { isEditingName = false }
        findViewById<View>(R.id.btnSaveGroupNameEdit).setOnClickListener { saveName() }
        edtGroupName.setImeActionLabel(getString(R.string.save), EditorInfo.IME_ACTION_DONE)
        edtGroupName.setOnEditorActionListener { _, actionId, _ ->
            when (actionId) {
                EditorInfo.IME_ACTION_DONE -> {
                    saveName()
                    return@setOnEditorActionListener true
                }
                else -> return@setOnEditorActionListener false
            }
        }

        LoaderManager.getInstance(this).initLoader(loaderID, null, object : LoaderManager.LoaderCallbacks<GroupMembers> {

            override fun onCreateLoader(id: Int, bundle: Bundle?): Loader<GroupMembers> {
                return EditClosedGroupLoader(this@EditLegacyClosedGroupActivity, groupID)
            }

            override fun onLoadFinished(loader: Loader<GroupMembers>, groupMembers: GroupMembers) {
                // We no longer need any subsequent loading events
                // (they will occur on every activity resume).
                LoaderManager.getInstance(this@EditLegacyClosedGroupActivity).destroyLoader(loaderID)

                members.clear()
                members.addAll(groupMembers.members.toHashSet())
                zombies.clear()
                zombies.addAll(groupMembers.zombieMembers.toHashSet())
                originalMembers.clear()
                originalMembers.addAll(members + zombies)
                updateMembers()
            }

            override fun onLoaderReset(loader: Loader<GroupMembers>) {
                updateMembers()
            }
        })
    }

    override fun onCreateOptionsMenu(menu: Menu): Boolean {
        menuInflater.inflate(R.menu.menu_edit_closed_group, menu)
        return allMembers.isNotEmpty() && !isLoading
    }
    // endregion

    // region Updating
    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        when (requestCode) {
            addUsersRequestCode -> {
                if (resultCode != RESULT_OK) return
                if (data == null || data.extras == null || !data.hasExtra(SelectContactsActivity.selectedContactsKey)) return

                val selectedContacts = data.extras!!.getStringArray(SelectContactsActivity.selectedContactsKey)!!.toSet()
                members.addAll(selectedContacts)
                updateMembers()
            }
        }
    }

    private fun handleIsEditingNameChanged() {
        cntGroupNameEdit.visibility = if (isEditingName) View.VISIBLE else View.INVISIBLE
        cntGroupNameDisplay.visibility = if (isEditingName) View.INVISIBLE else View.VISIBLE
        val inputMethodManager = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
        if (isEditingName) {
            edtGroupName.setText(name)
            edtGroupName.selectAll()
            edtGroupName.requestFocus()
            inputMethodManager.showSoftInput(edtGroupName, 0)
        } else {
            inputMethodManager.hideSoftInputFromWindow(edtGroupName.windowToken, 0)
        }
    }

    private fun updateMembers() {
        memberListAdapter.setMembers(allMembers)
        memberListAdapter.setZombieMembers(zombies)

        mainContentContainer.visibility = if (allMembers.isEmpty()) View.GONE else View.VISIBLE
        emptyStateContainer.visibility = if (allMembers.isEmpty()) View.VISIBLE else View.GONE

        invalidateOptionsMenu()
    }
    // endregion

    // region Interaction
    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        when (item.itemId) {
            R.id.action_apply -> if (!isLoading) { commitChanges() }
        }
        return super.onOptionsItemSelected(item)
    }

    private fun onMemberClick(member: String) {
        val bottomSheet = ClosedGroupEditingOptionsBottomSheet()
        bottomSheet.onRemoveTapped = {
            if (zombies.contains(member)) zombies.remove(member)
            else members.remove(member)
            updateMembers()
            bottomSheet.dismiss()
        }
        bottomSheet.show(supportFragmentManager, "GroupEditingOptionsBottomSheet")
    }

    private fun onAddMembersClick() {
        val intent = Intent(this@EditLegacyClosedGroupActivity, SelectContactsActivity::class.java)
        intent.putExtra(SelectContactsActivity.usersToExcludeKey, allMembers.toTypedArray())
        intent.putExtra(SelectContactsActivity.emptyStateTextKey, "No contacts to add")
        startActivityForResult(intent, addUsersRequestCode)
    }

    private fun saveName() {
        val name = edtGroupName.text.toString().trim()
        if (name.isEmpty()) {
            return Toast.makeText(this, R.string.activity_edit_closed_group_group_name_missing_error, Toast.LENGTH_SHORT).show()
        }
        if (name.length >= 64) {
            return Toast.makeText(this, R.string.activity_edit_closed_group_group_name_too_long_error, Toast.LENGTH_SHORT).show()
        }
        this.name = name
        lblGroupNameDisplay.text = name
        hasNameChanged = true
        isEditingName = false
    }

    private fun commitChanges() {
        val hasMemberListChanges = (allMembers != originalMembers)

        if (!hasNameChanged && !hasMemberListChanges) {
            return finish()
        }

        val name = if (hasNameChanged) this.name else originalName

        val members = this.allMembers.map {
            Recipient.from(this, Address.fromSerialized(it), false)
        }.toSet()
        val originalMembers = this.originalMembers.map {
            Recipient.from(this, Address.fromSerialized(it), false)
        }.toSet()

        var isClosedGroup: Boolean
        var groupPublicKey: String?
        try {
            groupPublicKey = GroupUtil.doubleDecodeGroupID(groupID).toHexString()
            isClosedGroup = DatabaseComponent.get(this).lokiAPIDatabase().isClosedGroup(groupPublicKey)
        } catch (e: IOException) {
            groupPublicKey = null
            isClosedGroup = false
        }

        if (members.isEmpty()) {
            return Toast.makeText(this, R.string.activity_edit_closed_group_not_enough_group_members_error, Toast.LENGTH_LONG).show()
        }

        val maxGroupMembers = if (isClosedGroup) groupSizeLimit else legacyGroupSizeLimit
        if (members.size >= maxGroupMembers) {
            return Toast.makeText(this, R.string.activity_create_closed_group_too_many_group_members_error, Toast.LENGTH_LONG).show()
        }

        val userPublicKey = TextSecurePreferences.getLocalNumber(this)!!
        val userAsRecipient = Recipient.from(this, Address.fromSerialized(userPublicKey), false)

        if (!members.contains(userAsRecipient) && !members.map { it.address.toString() }.containsAll(originalMembers.minus(userPublicKey))) {
            val message = "Can't leave while adding or removing other members."
            return Toast.makeText(this@EditLegacyClosedGroupActivity, message, Toast.LENGTH_LONG).show()
        }

        if (isClosedGroup) {
            isLoading = true
            loaderContainer.fadeIn()
            val promise: Promise<Any, Exception> = if (!members.contains(Recipient.from(this, Address.fromSerialized(userPublicKey), false))) {
                MessageSender.explicitLeave(groupPublicKey!!, false)
            } else {
                task {
                    if (hasNameChanged) {
                        MessageSender.explicitNameChange(groupPublicKey!!, name)
                    }
                    members.filterNot { it in originalMembers }.let { adds ->
                        if (adds.isNotEmpty()) MessageSender.explicitAddMembers(groupPublicKey!!, adds.map { it.address.serialize() })
                    }
                    originalMembers.filterNot { it in members }.let { removes ->
                        if (removes.isNotEmpty()) MessageSender.explicitRemoveMembers(groupPublicKey!!, removes.map { it.address.serialize() })
                    }
                }
            }
            promise.successUi {
                loaderContainer.fadeOut()
                isLoading = false
                updateGroupConfig()
                finish()
            }.failUi { exception ->
                val message = if (exception is MessageSender.Error) exception.description else "An error occurred"
                Toast.makeText(this@EditLegacyClosedGroupActivity, message, Toast.LENGTH_LONG).show()
                loaderContainer.fadeOut()
                isLoading = false
            }
        }
    }

    private fun updateGroupConfig() {
        val latestRecipient = storage.getRecipientSettings(Address.fromSerialized(groupID))
            ?: return Log.w("Loki", "No recipient settings when trying to update group config")
        val latestGroup = storage.getGroup(groupID)
            ?: return Log.w("Loki", "No group record when trying to update group config")
        groupConfigFactory.updateLegacyGroup(latestRecipient, latestGroup)
    }

    class GroupMembers(val members: List<String>, val zombieMembers: List<String>)
}