// Views/Inspection/ExecuteInspectionView.swift
// --------------------------------------------
// The primary work surface for completing an inspection.
// Renders the dynamic form_schema from the selected template.
// All writes go to SwiftData (offline-safe). Auto-saves every 30 seconds.

import SwiftUI
import SwiftData

struct ExecuteInspectionView: View {

    @Environment(\.modelContext) private var context
    @EnvironmentObject private var sync: SyncManager
    @EnvironmentObject private var auth: AuthManager

    let inspection: LocalInspection

    // Local state for the form — mirrors inspection.formData
    @State private var formValues: [String: String] = [:]
    @State private var showFlagIssue  = false
    @State private var showSubmitAlert = false
    @State private var showOfflineBanner = false
    @State private var isSaving = false
    @State private var isSubmitting = false
    @State private var submitMessage = ""

    // Auto-save timer
    private let autoSaveInterval: TimeInterval = 30

    private var template: LocalTemplate? {
        // Look up the template from SwiftData
        let id = inspection.templateServerId
        return try? context.fetch(
            FetchDescriptor<LocalTemplate>(predicate: #Predicate { $0.serverId == id })
        ).first
    }

    private var facility: LocalFacility? {
        let id = inspection.facilityServerId
        return try? context.fetch(
            FetchDescriptor<LocalFacility>(predicate: #Predicate { $0.serverId == id })
        ).first
    }

    private var formSchema: [[String: Any]] {
        template?.formSchema ?? []
    }

    var body: some View {
        ScrollView {
            LazyVStack(alignment: .leading, spacing: 16) {

                // ── Offline banner ─────────────────────────────────────────
                if !sync.isOnline {
                    HStack {
                        Image(systemName: "wifi.slash")
                        Text("Offline — your work saves locally and will sync automatically.")
                            .font(.callout)
                    }
                    .padding(12)
                    .frame(maxWidth: .infinity, alignment: .leading)
                    .background(Color.orange.opacity(0.15))
                    .clipShape(RoundedRectangle(cornerRadius: 8))
                    .padding(.horizontal)
                }

                // ── Inspection header ──────────────────────────────────────
                VStack(alignment: .leading, spacing: 4) {
                    Text(template?.name ?? "Inspection Form")
                        .font(.title2.bold())
                    Text(facility?.name ?? "")
                        .font(.subheadline)
                        .foregroundStyle(.secondary)
                    Text(inspection.inspectionDate.formatted(date: .long, time: .shortened))
                        .font(.caption)
                        .foregroundStyle(.tertiary)
                }
                .padding(.horizontal)

                Divider()

                // ── Form fields ────────────────────────────────────────────
                ForEach(formSchema.indices, id: \.self) { idx in
                    let field  = formSchema[idx]
                    let fid    = fieldId(field)
                    let ftype  = field["type"] as? String ?? ""

                    if !["button_submit", "button_print", "button_email"].contains(ftype) {
                        FormFieldView(
                            field: field,
                            value: Binding(
                                get: { formValues[fid] ?? "" },
                                set: { formValues[fid] = $0; saveDraft() }
                            ),
                            onPhotoSelected: { localPath in
                                handlePhotoSelected(localPath: localPath, field: field)
                            }
                        )
                        .padding(.horizontal)
                    }
                }

                // ── Inspector notes ────────────────────────────────────────
                VStack(alignment: .leading, spacing: 6) {
                    Text("Inspector Notes")
                        .font(.subheadline.weight(.medium))
                    TextEditor(text: Binding(
                        get: { inspection.inspectorNotes },
                        set: { inspection.inspectorNotes = $0 }
                    ))
                    .frame(minHeight: 80)
                    .overlay(RoundedRectangle(cornerRadius: 6).stroke(Color(.systemGray4)))
                }
                .padding(.horizontal)

                Divider()

                // ── Action buttons ─────────────────────────────────────────
                VStack(spacing: 12) {
                    // Flag Issue
                    Button {
                        showFlagIssue = true
                    } label: {
                        Label("Flag an Issue", systemImage: "exclamationmark.triangle")
                            .frame(maxWidth: .infinity)
                            .padding(.vertical, 12)
                    }
                    .buttonStyle(.bordered)
                    .tint(.orange)

                    // Save Draft
                    Button {
                        saveDraft(force: true)
                    } label: {
                        Label(isSaving ? "Saving…" : "Save Draft", systemImage: "square.and.arrow.down")
                            .frame(maxWidth: .infinity)
                            .padding(.vertical, 12)
                    }
                    .buttonStyle(.bordered)
                    .disabled(isSaving)

                    // Submit Inspection
                    Button {
                        showSubmitAlert = true
                    } label: {
                        Label("Submit Inspection", systemImage: "checkmark.circle.fill")
                            .frame(maxWidth: .infinity)
                            .padding(.vertical, 14)
                    }
                    .buttonStyle(.borderedProminent)
                    .disabled(isSubmitting)
                }
                .padding(.horizontal)
                .padding(.bottom, 32)
            }
        }
        .navigationTitle("Inspection")
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItem(placement: .topBarTrailing) {
                ConnectivityBadge()
            }
        }
        .onAppear {
            // Load saved form data into local state
            formValues = inspection.formData.compactMapValues { "\($0)" }
        }
        .onDisappear {
            saveDraft(force: true)
        }
        // Auto-save every 30 seconds
        .task {
            while !Task.isCancelled {
                try? await Task.sleep(for: .seconds(autoSaveInterval))
                saveDraft()
            }
        }
        .sheet(isPresented: $showFlagIssue) {
            FlagIssueView(inspection: inspection)
        }
        .alert("Submit Inspection", isPresented: $showSubmitAlert) {
            Button("Submit", role: .none) { submitInspection() }
            Button("Cancel", role: .cancel) {}
        } message: {
            Text("Once submitted, the inspection cannot be edited. " +
                 (sync.isOnline
                  ? "It will be sent to the server now."
                  : "It will sync automatically when you're back online."))
        }
    }

    // ── Save Draft ─────────────────────────────────────────────────────────

    private func saveDraft(force: Bool = false) {
        guard inspection.status == "draft" else { return }
        if force { isSaving = true }

        // Write form values back to the model
        var data: [String: Any] = [:]
        for (k, v) in formValues { data[k] = v }
        inspection.formData      = data
        inspection.lastModifiedAt = Date()

        try? context.save()
        if force {
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
                isSaving = false
            }
        }
    }

    // ── Submit ─────────────────────────────────────────────────────────────

    private func submitInspection() {
        isSubmitting = true

        // Persist final form data
        var data: [String: Any] = [:]
        for (k, v) in formValues { data[k] = v }
        inspection.formData = data

        // Compute score
        inspection.overallScore = inspection.computeScore(fromSchema: formSchema)
        inspection.status        = "completed"
        inspection.completedAt   = Date()
        inspection.syncStatus    = "pending"

        try? context.save()

        // Trigger sync if online
        if sync.isOnline {
            Task { await sync.triggerSync() }
        }

        isSubmitting = false
    }

    // ── Photo handling ─────────────────────────────────────────────────────

    private func handlePhotoSelected(localPath: String, field: [String: Any]) {
        let fid = fieldId(field)

        // Store local sentinel in form values
        formValues[fid] = "local://\(localPath)"

        // Create PendingPhoto record
        let photo = PendingPhoto(
            localFilePath: localPath,
            entityType:    "inspection",
            entityLocalId: inspection.localId,
            fieldId:       fid
        )
        inspection.pendingPhotos.append(photo)
        context.insert(photo)
        try? context.save()
    }

    // ── Helpers ────────────────────────────────────────────────────────────

    private func fieldId(_ field: [String: Any]) -> String {
        if let id = field["id"] as? String { return id }
        if let id = field["id"] as? Int    { return String(id) }
        return UUID().uuidString
    }
}

// MARK: - Connectivity Badge

struct ConnectivityBadge: View {
    @EnvironmentObject private var sync: SyncManager

    var body: some View {
        HStack(spacing: 4) {
            Circle()
                .fill(sync.isOnline ? Color.green : Color.orange)
                .frame(width: 8, height: 8)
            Text(sync.isOnline ? "Online" : "Offline")
                .font(.caption2)
                .foregroundStyle(.secondary)
        }
    }
}