package com.example.ui.viewmodel

import android.app.Application
import androidx.lifecycle.AndroidViewModel
import androidx.lifecycle.ViewModel
import androidx.lifecycle.ViewModelProvider
import androidx.lifecycle.viewModelScope
import com.example.data.local.AppDatabase
import com.example.data.model.*
import com.example.data.repository.SatarkRepository
import kotlinx.coroutines.flow.*
import kotlinx.coroutines.launch

data class UiState(
    val currentScreen: Screen = Screen.SPLASH,
    val previousScreen: Screen? = null,
    val currentLanguage: AppLanguage = AppLanguage.BN,
    val userName: String = "Mohammad Shakib",
    val userPhone: String = "+880 1712-345678",
    val isNidVerified: Boolean = true,
    val isAdminMode: Boolean = false,

    // Collections
    val companies: List<Company> = emptyList(),
    val reports: List<ScamReport> = emptyList(),
    val publicWarnings: List<PublicWarning> = emptyList(),
    val notifications: List<AppNotification> = emptyList(),
    val unreadNotificationCount: Int = 0,

    // Detail & Selection
    val selectedCompany: Company? = null,
    val selectedWarningId: String? = null,

    // Search filters
    val searchQuery: String = "",
    val selectedCategoryFilter: String? = null,
    val selectedDivisionFilter: String? = null,
    val selectedRiskFilter: VerificationStatus? = null,

    // Tracking
    val searchTrackingId: String = "BD-SCAM-8942",

    // Report submission flow
    val reportStep: Int = 1, // 1: Form, 2: Proof upload, 3: Success confirmation
    val reportTargetName: String = "",
    val reportContactInfo: String = "",
    val reportCategory: String = "Fake E-commerce",
    val reportCity: String = "Dhaka",
    val reportDescription: String = "",
    val reportMoneyLost: String = "",
    val reportIncidentDate: String = "24 Aug 2026",
    val reportIsAnonymous: Boolean = false,
    val evidenceList: List<EvidenceItem> = emptyList(),
    val reportErrors: Map<String, String> = emptyMap(),
    val isSubmittingReport: Boolean = false,
    val submittedReportId: String? = null,

    // Admin Review Panel
    val adminSelectedTab: Int = 0, // 0: Pending, 1: Verified, 2: Rejected
    val adminReviewingReportId: String? = null,
    val adminNotesInput: String = ""
)

class SatarkViewModel(private val repository: SatarkRepository) : ViewModel() {

    private val _uiState = MutableStateFlow(UiState())
    val uiState: StateFlow<UiState> = _uiState.asStateFlow()

    init {
        viewModelScope.launch {
            repository.initializeSeedDataIfEmpty()
        }

        viewModelScope.launch {
            combine(
                repository.allCompanies,
                repository.allReports,
                repository.allWarnings,
                repository.allNotifications
            ) { companies, reports, warnings, notifications ->
                _uiState.update { current ->
                    current.copy(
                        companies = companies,
                        reports = reports,
                        publicWarnings = warnings,
                        notifications = notifications,
                        unreadNotificationCount = notifications.count { !it.isRead },
                        selectedCompany = if (current.selectedCompany != null) {
                            companies.find { it.id == current.selectedCompany.id } ?: current.selectedCompany
                        } else null
                    )
                }
            }.collect()
        }
    }

    fun navigateTo(screen: Screen) {
        _uiState.update { current ->
            current.copy(
                previousScreen = current.currentScreen,
                currentScreen = screen
            )
        }
    }

    fun navigateBack() {
        _uiState.update { current ->
            val prev = current.previousScreen ?: Screen.HOME
            current.copy(
                currentScreen = if (current.currentScreen == Screen.HOME) Screen.HOME else prev,
                previousScreen = null
            )
        }
    }

    fun toggleLanguage() {
        _uiState.update {
            it.copy(
                currentLanguage = if (it.currentLanguage == AppLanguage.BN) AppLanguage.EN else AppLanguage.BN
            )
        }
    }

    fun setLanguage(lang: AppLanguage) {
        _uiState.update { it.copy(currentLanguage = lang) }
    }

    fun completeSplash() {
        navigateTo(Screen.ONBOARDING)
    }

    fun completeOnboarding() {
        navigateTo(Screen.AUTH)
    }

    fun setAuthenticatedUser(name: String, phone: String, isNid: Boolean) {
        _uiState.update {
            it.copy(
                userName = name.ifBlank { "Mohammad Shakib" },
                userPhone = phone.ifBlank { "+880 1712-345678" },
                isNidVerified = isNid,
                currentScreen = Screen.HOME
            )
        }
    }

    fun selectCompany(companyId: String) {
        val found = _uiState.value.companies.find { it.id == companyId }
        _uiState.update {
            it.copy(
                selectedCompany = found,
                currentScreen = Screen.COMPANY_PROFILE,
                previousScreen = it.currentScreen
            )
        }
    }

    fun selectWarning(warningId: String?) {
        _uiState.update {
            it.copy(
                selectedWarningId = warningId,
                currentScreen = Screen.PUBLIC_WARNINGS
            )
        }
    }

    fun startReportWithEntity(entityName: String) {
        _uiState.update {
            it.copy(
                reportStep = 1,
                reportTargetName = entityName,
                reportContactInfo = "",
                reportDescription = "",
                reportMoneyLost = "",
                evidenceList = emptyList(),
                reportErrors = emptyMap(),
                submittedReportId = null,
                currentScreen = Screen.REPORT_FORM,
                previousScreen = it.currentScreen
            )
        }
    }

    fun updateReportFields(
        targetName: String? = null,
        contactInfo: String? = null,
        category: String? = null,
        city: String? = null,
        description: String? = null,
        moneyLost: String? = null,
        isAnonymous: Boolean? = null,
        reporterName: String? = null,
        reporterPhone: String? = null
    ) {
        _uiState.update { current ->
            current.copy(
                reportTargetName = targetName ?: current.reportTargetName,
                reportContactInfo = contactInfo ?: current.reportContactInfo,
                reportCategory = category ?: current.reportCategory,
                reportCity = city ?: current.reportCity,
                reportDescription = description ?: current.reportDescription,
                reportMoneyLost = moneyLost ?: current.reportMoneyLost,
                reportIsAnonymous = isAnonymous ?: current.reportIsAnonymous,
                reportErrors = emptyMap()
            )
        }
    }

    fun proceedToProofUpload() {
        val current = _uiState.value
        val errors = mutableMapOf<String, String>()

        if (current.reportTargetName.trim().isBlank()) {
            errors["targetName"] = if (current.currentLanguage == AppLanguage.BN) 
                "অভিযুক্ত ব্যক্তি বা প্রতিষ্ঠানের নাম দিন" 
            else 
                "Entity name is required"
        }
        if (current.reportContactInfo.trim().isBlank()) {
            errors["contactInfo"] = if (current.currentLanguage == AppLanguage.BN) 
                "মোবাইল, বিকাশ নম্বর অথবা ফেসবুক পেজ লিংক দিন" 
            else 
                "Contact info or URL is required"
        }
        if (current.reportDescription.trim().length < 15) {
            errors["description"] = if (current.currentLanguage == AppLanguage.BN) 
                "কমপক্ষে ১৫ অক্ষরে বিস্তারিত বিবরণ লিখুন" 
            else 
                "Please describe in at least 15 characters"
        }

        if (errors.isNotEmpty()) {
            _uiState.update { it.copy(reportErrors = errors) }
        } else {
            _uiState.update {
                it.copy(
                    reportStep = 2,
                    reportErrors = emptyMap(),
                    currentScreen = Screen.PROOF_UPLOAD
                )
            }
        }
    }

    fun backToReportStep1() {
        _uiState.update {
            it.copy(
                reportStep = 1,
                currentScreen = Screen.REPORT_FORM
            )
        }
    }

    fun addEvidence(type: String, title: String, note: String) {
        val newItem = EvidenceItem(
            id = "EVID-${System.currentTimeMillis()}",
            title = title,
            type = type,
            timestamp = "24 Aug 2026",
            note = note
        )
        _uiState.update {
            it.copy(evidenceList = it.evidenceList + newItem)
        }
    }

    fun removeEvidence(id: String) {
        _uiState.update {
            it.copy(evidenceList = it.evidenceList.filterNot { item -> item.id == id })
        }
    }

    fun submitReport() {
        val current = _uiState.value
        val generatedId = "BD-SCAM-${(8950..9999).random()}"
        val lost = current.reportMoneyLost.toDoubleOrNull() ?: 0.0

        val newReport = ScamReport(
            id = generatedId,
            targetEntityName = current.reportTargetName.trim(),
            contactInfo = current.reportContactInfo.trim(),
            scamCategory = current.reportCategory,
            city = current.reportCity,
            incidentDescription = current.reportDescription.trim(),
            moneyLostBdt = lost,
            dateReported = "24 Aug 2026",
            incidentDate = current.reportIncidentDate,
            status = ReportStatus.PENDING_REVIEW,
            isAnonymous = current.reportIsAnonymous,
            reporterName = if (current.reportIsAnonymous) "Anonymous Citizen" else current.userName,
            reporterPhone = if (current.reportIsAnonymous) "+880 1***-***" else current.userPhone,
            adminNotes = "Under initial triage by Satark BD cyber cell."
        )

        viewModelScope.launch {
            _uiState.update { it.copy(isSubmittingReport = true) }
            repository.submitReport(newReport)
            _uiState.update {
                it.copy(
                    isSubmittingReport = false,
                    reportStep = 3,
                    submittedReportId = generatedId,
                    searchTrackingId = generatedId
                )
            }
        }
    }

    fun resetReportForm() {
        _uiState.update {
            it.copy(
                reportStep = 1,
                reportTargetName = "",
                reportContactInfo = "",
                reportDescription = "",
                reportMoneyLost = "",
                evidenceList = emptyList(),
                reportErrors = emptyMap(),
                submittedReportId = null
            )
        }
    }

    fun setSearchQuery(query: String) {
        _uiState.update { it.copy(searchQuery = query) }
    }

    fun setCategoryFilter(cat: String?) {
        _uiState.update { it.copy(selectedCategoryFilter = cat) }
    }

    fun setDivisionFilter(div: String?) {
        _uiState.update { it.copy(selectedDivisionFilter = div) }
    }

    fun setRiskFilter(risk: VerificationStatus?) {
        _uiState.update { it.copy(selectedRiskFilter = risk) }
    }

    fun setSearchTrackingId(id: String) {
        _uiState.update { it.copy(searchTrackingId = id) }
    }

    fun toggleAdminMode() {
        _uiState.update { it.copy(isAdminMode = !it.isAdminMode) }
    }

    fun setAdminTab(tab: Int) {
        _uiState.update { it.copy(adminSelectedTab = tab, adminReviewingReportId = null) }
    }

    fun selectReportForAdminReview(reportId: String?) {
        _uiState.update { it.copy(adminReviewingReportId = reportId, adminNotesInput = "") }
    }

    fun setAdminNotesInput(notes: String) {
        _uiState.update { it.copy(adminNotesInput = notes) }
    }

    fun approveReport(reportId: String, publishWarning: Boolean) {
        viewModelScope.launch {
            val note = _uiState.value.adminNotesInput.ifBlank { "Verified with documentary evidence and transaction receipts." }
            val status = if (publishWarning) ReportStatus.VERIFIED_WARNING_ISSUED else ReportStatus.LEGAL_ESCALATION
            repository.updateReportStatus(reportId, status, note, isPublicAlert = publishWarning)
            _uiState.update { it.copy(adminReviewingReportId = null) }
        }
    }

    fun rejectReport(reportId: String) {
        viewModelScope.launch {
            val note = _uiState.value.adminNotesInput.ifBlank { "Insufficient proof provided." }
            repository.updateReportStatus(reportId, ReportStatus.REJECTED, note, isPublicAlert = false)
            _uiState.update { it.copy(adminReviewingReportId = null) }
        }
    }

    fun markNotificationRead(id: String) {
        viewModelScope.launch {
            repository.markAllNotificationsRead()
        }
    }

    fun logout() {
        _uiState.update {
            it.copy(
                userName = "Guest Citizen",
                userPhone = "+880 1700-000000",
                isNidVerified = false,
                currentScreen = Screen.AUTH
            )
        }
    }
}

class SatarkViewModelFactory(private val repository: SatarkRepository) : ViewModelProvider.Factory {
    @Suppress("UNCHECKED_CAST")
    override fun <T : ViewModel> create(modelClass: Class<T>): T {
        if (modelClass.isAssignableFrom(SatarkViewModel::class.java)) {
            return SatarkViewModel(repository) as T
        }
        throw IllegalArgumentException("Unknown ViewModel class")
    }
}