package com.example.ui.screens

import android.widget.Toast
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.items
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.Add
import androidx.compose.material.icons.filled.Business
import androidx.compose.material.icons.filled.CheckCircle
import androidx.compose.material.icons.filled.Delete
import androidx.compose.material.icons.filled.Handshake
import androidx.compose.material.icons.filled.PauseCircle
import androidx.compose.material.icons.filled.Phone
import androidx.compose.material.icons.filled.Place
import androidx.compose.material.icons.filled.Search
import androidx.compose.material3.AlertDialog
import androidx.compose.material3.Button
import androidx.compose.material3.ButtonDefaults
import androidx.compose.material3.Card
import androidx.compose.material3.CardDefaults
import androidx.compose.material3.FilterChip
import androidx.compose.material3.FilterChipDefaults
import androidx.compose.material3.FloatingActionButton
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.OutlinedTextField
import androidx.compose.material3.Surface
import androidx.compose.material3.Switch
import androidx.compose.material3.SwitchDefaults
import androidx.compose.material3.Text
import androidx.compose.material3.TextButton
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableIntStateOf
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.platform.testTag
import androidx.compose.ui.text.font.FontFamily
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import androidx.lifecycle.compose.collectAsStateWithLifecycle
import com.example.data.local.entity.PartnerEntity
import com.example.ui.theme.EmeraldDark
import com.example.ui.theme.EmeraldLight
import com.example.ui.theme.EmeraldPrimary
import com.example.ui.viewmodel.MarketingViewModel

@Composable
fun PartnerManagementScreen(
    viewModel: MarketingViewModel,
    modifier: Modifier = Modifier
) {
    val context = LocalContext.current
    val partners by viewModel.partners.collectAsStateWithLifecycle()
    val account by viewModel.account.collectAsStateWithLifecycle()

    var showAddDialog by remember { mutableStateOf(false) }
    var partnerToDelete by remember { mutableStateOf<PartnerEntity?>(null) }
    var searchQuery by remember { mutableStateOf("") }
    var filterTab by remember { mutableIntStateOf(0) } // 0: All, 1: Active, 2: Deactive

    val isAccountActive = account?.status == "ACTIVE"

    val filteredPartners = partners.filter { p ->
        val matchesSearch = searchQuery.isBlank() ||
                p.name.contains(searchQuery, ignoreCase = true) ||
                p.mobileNumber.contains(searchQuery) ||
                p.district.contains(searchQuery, ignoreCase = true) ||
                p.organization.contains(searchQuery, ignoreCase = true)

        val matchesStatus = when (filterTab) {
            1 -> p.isActive
            2 -> !p.isActive
            else -> true
        }

        matchesSearch && matchesStatus
    }

    Box(modifier = modifier.fillMaxSize()) {
        Column(
            modifier = Modifier
                .fillMaxSize()
                .padding(horizontal = 16.dp)
        ) {
            Spacer(modifier = Modifier.height(10.dp))

            // Account Active / Deactive Global Controller Card
            Card(
                modifier = Modifier.fillMaxWidth(),
                shape = RoundedCornerShape(14.dp),
                colors = CardDefaults.cardColors(
                    containerColor = if (isAccountActive) Color(0xFFF0FDF4) else Color(0xFFFEF2F2)
                ),
                elevation = CardDefaults.cardElevation(defaultElevation = 2.dp)
            ) {
                Row(
                    modifier = Modifier.padding(14.dp),
                    verticalAlignment = Alignment.CenterVertically,
                    horizontalArrangement = Arrangement.SpaceBetween
                ) {
                    Row(
                        verticalAlignment = Alignment.CenterVertically,
                        modifier = Modifier.weight(1f)
                    ) {
                        Box(
                            modifier = Modifier
                                .size(40.dp)
                                .clip(CircleShape)
                                .background(if (isAccountActive) EmeraldPrimary else Color(0xFFE11D48)),
                            contentAlignment = Alignment.Center
                        ) {
                            Icon(
                                imageVector = if (isAccountActive) Icons.Default.CheckCircle else Icons.Default.PauseCircle,
                                contentDescription = null,
                                tint = Color.White,
                                modifier = Modifier.size(22.dp)
                            )
                        }
                        Spacer(modifier = Modifier.width(12.dp))
                        Column {
                            Row(verticalAlignment = Alignment.CenterVertically) {
                                Text(
                                    text = "System Status: ",
                                    fontWeight = FontWeight.Bold,
                                    fontSize = 14.sp
                                )
                                Text(
                                    text = if (isAccountActive) "ACTIVE" else "DEACTIVE",
                                    fontWeight = FontWeight.Bold,
                                    fontSize = 14.sp,
                                    color = if (isAccountActive) EmeraldPrimary else Color(0xFFE11D48)
                                )
                            }
                            Text(
                                text = if (isAccountActive) "Messaging & operations running normally" else "Broadcasting & partner operations paused",
                                fontSize = 11.sp,
                                color = MaterialTheme.colorScheme.onSurfaceVariant
                            )
                        }
                    }

                    Switch(
                        checked = isAccountActive,
                        onCheckedChange = { newState ->
                            viewModel.toggleAccountStatus(newState)
                        },
                        colors = SwitchDefaults.colors(
                            checkedThumbColor = Color.White,
                            checkedTrackColor = EmeraldPrimary,
                            uncheckedThumbColor = Color.White,
                            uncheckedTrackColor = Color(0xFF94A3B8)
                        ),
                        modifier = Modifier.testTag("account_active_switch")
                    )
                }
            }

            Spacer(modifier = Modifier.height(14.dp))

            // Partner Management Header & Search
            Row(
                modifier = Modifier.fillMaxWidth(),
                horizontalArrangement = Arrangement.SpaceBetween,
                verticalAlignment = Alignment.CenterVertically
            ) {
                Row(verticalAlignment = Alignment.CenterVertically) {
                    Icon(
                        imageVector = Icons.Default.Handshake,
                        contentDescription = null,
                        tint = EmeraldPrimary,
                        modifier = Modifier.size(20.dp)
                    )
                    Spacer(modifier = Modifier.width(6.dp))
                    Text(
                        text = "Partner Management (${partners.size})",
                        fontWeight = FontWeight.Bold,
                        fontSize = 16.sp
                    )
                }

                Surface(
                    shape = RoundedCornerShape(12.dp),
                    color = EmeraldPrimary.copy(alpha = 0.12f)
                ) {
                    Text(
                        text = "${partners.count { it.isActive }} Active",
                        fontSize = 11.sp,
                        fontWeight = FontWeight.Bold,
                        color = EmeraldDark,
                        modifier = Modifier.padding(horizontal = 8.dp, vertical = 4.dp)
                    )
                }
            }

            Spacer(modifier = Modifier.height(8.dp))

            // Search Bar
            OutlinedTextField(
                value = searchQuery,
                onValueChange = { searchQuery = it },
                placeholder = { Text("Search partner name, mobile, district...") },
                leadingIcon = { Icon(Icons.Default.Search, contentDescription = null) },
                singleLine = true,
                shape = RoundedCornerShape(12.dp),
                modifier = Modifier
                    .fillMaxWidth()
                    .testTag("search_partner_input")
            )

            Spacer(modifier = Modifier.height(8.dp))

            // Filter Chips: All, Active, Deactive
            Row(
                modifier = Modifier.fillMaxWidth(),
                horizontalArrangement = Arrangement.spacedBy(8.dp)
            ) {
                FilterChip(
                    selected = filterTab == 0,
                    onClick = { filterTab = 0 },
                    label = { Text("All (${partners.size})", fontSize = 11.sp) },
                    colors = FilterChipDefaults.filterChipColors(
                        selectedContainerColor = EmeraldPrimary.copy(alpha = 0.15f),
                        selectedLabelColor = EmeraldPrimary
                    )
                )
                FilterChip(
                    selected = filterTab == 1,
                    onClick = { filterTab = 1 },
                    label = { Text("Active (${partners.count { it.isActive }})", fontSize = 11.sp) },
                    colors = FilterChipDefaults.filterChipColors(
                        selectedContainerColor = EmeraldPrimary.copy(alpha = 0.15f),
                        selectedLabelColor = EmeraldPrimary
                    )
                )
                FilterChip(
                    selected = filterTab == 2,
                    onClick = { filterTab = 2 },
                    label = { Text("Deactive (${partners.count { !it.isActive }})", fontSize = 11.sp) },
                    colors = FilterChipDefaults.filterChipColors(
                        selectedContainerColor = Color(0xFFFFE4E6),
                        selectedLabelColor = Color(0xFFE11D48)
                    )
                )
            }

            Spacer(modifier = Modifier.height(8.dp))

            // Partners List
            if (filteredPartners.isEmpty()) {
                Box(
                    modifier = Modifier
                        .fillMaxSize()
                        .weight(1f),
                    contentAlignment = Alignment.Center
                ) {
                    Text("No partners found matching criteria.", color = Color.Gray)
                }
            } else {
                LazyColumn(
                    modifier = Modifier.weight(1f),
                    verticalArrangement = Arrangement.spacedBy(10.dp)
                ) {
                    items(filteredPartners) { partner ->
                        PartnerItemCard(
                            partner = partner,
                            onToggleActive = { active ->
                                viewModel.togglePartnerActive(partner.id, active)
                            },
                            onDelete = { partnerToDelete = partner }
                        )
                    }
                    item {
                        Spacer(modifier = Modifier.height(80.dp))
                    }
                }
            }
        }

        // Floating Action Button to Add Partner
        FloatingActionButton(
            onClick = { showAddDialog = true },
            modifier = Modifier
                .align(Alignment.BottomEnd)
                .padding(20.dp)
                .testTag("add_partner_fab"),
            containerColor = EmeraldPrimary,
            contentColor = Color.White
        ) {
            Icon(Icons.Default.Add, contentDescription = "Add Partner")
        }

        // Add Partner Dialog
        if (showAddDialog) {
            AddPartnerDialog(
                onDismiss = { showAddDialog = false },
                onAdd = { newPartner ->
                    viewModel.addPartner(newPartner)
                    showAddDialog = false
                    Toast.makeText(context, "Partner '${newPartner.name}' created!", Toast.LENGTH_SHORT).show()
                }
            )
        }

        // Delete Partner Confirmation Dialog
        partnerToDelete?.let { partner ->
            AlertDialog(
                onDismissRequest = { partnerToDelete = null },
                title = { Text("Remove Partner") },
                text = { Text("Are you sure you want to remove partner '${partner.name}' (${partner.district})?") },
                confirmButton = {
                    Button(
                        onClick = {
                            viewModel.deletePartner(partner)
                            partnerToDelete = null
                        },
                        colors = ButtonDefaults.buttonColors(containerColor = Color(0xFFE11D48))
                    ) {
                        Text("Remove")
                    }
                },
                dismissButton = {
                    TextButton(onClick = { partnerToDelete = null }) {
                        Text("Cancel")
                    }
                }
            )
        }
    }
}

@Composable
fun PartnerItemCard(
    partner: PartnerEntity,
    onToggleActive: (Boolean) -> Unit,
    onDelete: () -> Unit
) {
    Card(
        modifier = Modifier.fillMaxWidth(),
        shape = RoundedCornerShape(12.dp),
        colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surface),
        elevation = CardDefaults.cardElevation(defaultElevation = 2.dp)
    ) {
        Column(modifier = Modifier.padding(14.dp)) {
            Row(
                modifier = Modifier.fillMaxWidth(),
                horizontalArrangement = Arrangement.SpaceBetween,
                verticalAlignment = Alignment.Top
            ) {
                Column(modifier = Modifier.weight(1f)) {
                    Text(
                        text = partner.name,
                        fontWeight = FontWeight.Bold,
                        fontSize = 15.sp,
                        color = MaterialTheme.colorScheme.onSurface
                    )
                    if (partner.organization.isNotBlank()) {
                        Text(
                            text = partner.organization,
                            fontSize = 12.sp,
                            color = MaterialTheme.colorScheme.onSurfaceVariant
                        )
                    }
                    Spacer(modifier = Modifier.height(2.dp))
                    Row(verticalAlignment = Alignment.CenterVertically) {
                        Icon(
                            imageVector = Icons.Default.Phone,
                            contentDescription = null,
                            tint = EmeraldPrimary,
                            modifier = Modifier.size(13.dp)
                        )
                        Spacer(modifier = Modifier.width(4.dp))
                        Text(
                            text = partner.mobileNumber,
                            fontSize = 12.sp,
                            fontFamily = FontFamily.Monospace,
                            fontWeight = FontWeight.SemiBold,
                            color = EmeraldPrimary
                        )
                    }
                }

                // Active / Deactive Switch
                Column(horizontalAlignment = Alignment.End) {
                    Row(verticalAlignment = Alignment.CenterVertically) {
                        Text(
                            text = if (partner.isActive) "Active" else "Deactive",
                            fontSize = 11.sp,
                            fontWeight = FontWeight.Bold,
                            color = if (partner.isActive) EmeraldDark else Color(0xFFE11D48)
                        )
                        Spacer(modifier = Modifier.width(6.dp))
                        Switch(
                            checked = partner.isActive,
                            onCheckedChange = onToggleActive,
                            colors = SwitchDefaults.colors(
                                checkedThumbColor = Color.White,
                                checkedTrackColor = EmeraldPrimary,
                                uncheckedThumbColor = Color.White,
                                uncheckedTrackColor = Color(0xFF94A3B8)
                            )
                        )
                    }
                }
            }

            Spacer(modifier = Modifier.height(8.dp))

            // District, State, PIN and Partner Type Row
            Row(
                modifier = Modifier.fillMaxWidth(),
                verticalAlignment = Alignment.CenterVertically,
                horizontalArrangement = Arrangement.SpaceBetween
            ) {
                Row(verticalAlignment = Alignment.CenterVertically) {
                    Icon(
                        imageVector = Icons.Default.Place,
                        contentDescription = null,
                        tint = Color.Gray,
                        modifier = Modifier.size(13.dp)
                    )
                    Spacer(modifier = Modifier.width(4.dp))
                    val loc = listOf(partner.district, partner.state, partner.pinCode).filter { it.isNotBlank() }
                    Text(
                        text = if (loc.isNotEmpty()) loc.joinToString(", ") else "Location Unspecified",
                        fontSize = 12.sp,
                        color = MaterialTheme.colorScheme.onSurfaceVariant
                    )
                }

                Row(verticalAlignment = Alignment.CenterVertically) {
                    Surface(
                        shape = RoundedCornerShape(8.dp),
                        color = Color(0xFFE0F2FE)
                    ) {
                        Text(
                            text = partner.partnerType,
                            fontSize = 10.sp,
                            fontWeight = FontWeight.SemiBold,
                            color = Color(0xFF0369A1),
                            modifier = Modifier.padding(horizontal = 6.dp, vertical = 2.dp)
                        )
                    }
                    Spacer(modifier = Modifier.width(8.dp))
                    IconButton(
                        onClick = onDelete,
                        modifier = Modifier.size(28.dp)
                    ) {
                        Icon(
                            imageVector = Icons.Default.Delete,
                            contentDescription = "Remove Partner",
                            tint = Color(0xFFEF4444),
                            modifier = Modifier.size(18.dp)
                        )
                    }
                }
            }
        }
    }
}

@Composable
fun AddPartnerDialog(
    onDismiss: () -> Unit,
    onAdd: (PartnerEntity) -> Unit
) {
    var name by remember { mutableStateOf("") }
    var organization by remember { mutableStateOf("") }
    var mobile by remember { mutableStateOf("") }
    var district by remember { mutableStateOf("") }
    var state by remember { mutableStateOf("") }
    var pinCode by remember { mutableStateOf("") }
    var partnerType by remember { mutableStateOf("Channel Partner") }

    AlertDialog(
        onDismissRequest = onDismiss,
        title = {
            Row(verticalAlignment = Alignment.CenterVertically) {
                Icon(Icons.Default.Business, contentDescription = null, tint = EmeraldPrimary)
                Spacer(modifier = Modifier.width(8.dp))
                Text("Add Business Partner")
            }
        },
        text = {
            Column(
                modifier = Modifier.fillMaxWidth(),
                verticalArrangement = Arrangement.spacedBy(8.dp)
            ) {
                OutlinedTextField(
                    value = name,
                    onValueChange = { name = it },
                    label = { Text("Partner Name *") },
                    singleLine = true,
                    modifier = Modifier.fillMaxWidth()
                )
                OutlinedTextField(
                    value = organization,
                    onValueChange = { organization = it },
                    label = { Text("Business / Firm Name") },
                    singleLine = true,
                    modifier = Modifier.fillMaxWidth()
                )
                OutlinedTextField(
                    value = mobile,
                    onValueChange = { mobile = it },
                    label = { Text("Mobile Number (10 digits) *") },
                    singleLine = true,
                    modifier = Modifier.fillMaxWidth()
                )
                Row(
                    modifier = Modifier.fillMaxWidth(),
                    horizontalArrangement = Arrangement.spacedBy(8.dp)
                ) {
                    OutlinedTextField(
                        value = district,
                        onValueChange = { district = it },
                        label = { Text("District *") },
                        singleLine = true,
                        modifier = Modifier.weight(1f)
                    )
                    OutlinedTextField(
                        value = state,
                        onValueChange = { state = it },
                        label = { Text("State") },
                        singleLine = true,
                        modifier = Modifier.weight(1f)
                    )
                }
                OutlinedTextField(
                    value = pinCode,
                    onValueChange = { pinCode = it },
                    label = { Text("PIN Code") },
                    singleLine = true,
                    modifier = Modifier.fillMaxWidth()
                )

                Text("Partner Type:", fontSize = 11.sp, fontWeight = FontWeight.SemiBold)
                Row(
                    modifier = Modifier.fillMaxWidth(),
                    horizontalArrangement = Arrangement.spacedBy(6.dp)
                ) {
                    listOf("Channel Partner", "Distributor", "Franchise").forEach { type ->
                        FilterChip(
                            selected = partnerType == type,
                            onClick = { partnerType = type },
                            label = { Text(type, fontSize = 10.sp) }
                        )
                    }
                }
            }
        },
        confirmButton = {
            Button(
                onClick = {
                    if (name.isNotBlank() && mobile.isNotBlank()) {
                        val cleanMobile = if (mobile.startsWith("+")) mobile else "+91${mobile.takeLast(10)}"
                        onAdd(
                            PartnerEntity(
                                name = name.trim(),
                                organization = organization.trim(),
                                mobileNumber = cleanMobile,
                                district = district.trim(),
                                state = state.trim(),
                                pinCode = pinCode.trim(),
                                partnerType = partnerType,
                                isActive = true
                            )
                        )
                    }
                },
                colors = ButtonDefaults.buttonColors(containerColor = EmeraldPrimary)
            ) {
                Text("Save Partner")
            }
        },
        dismissButton = {
            TextButton(onClick = onDismiss) { Text("Cancel") }
        }
    )
}