//
//  RuleDetailSheet.swift
//  Severed
//

import SwiftData
import SwiftUI

/// The card-style rule summary shown when tapping a rule: icon pair, live
/// status, the key facts, and "Edit Rule" — which morphs the sheet into the
/// editor, as in the reference app. A hard-locked rule shows a lock notice
/// instead of the edit button.
struct RuleDetailSheet: View {
    let rule: BlockingRule

    @Environment(\.dismiss) private var dismiss
    @Environment(\.modelContext) private var modelContext
    @State private var isEditing = false
    @State private var pendingDeletion = false

    var body: some View {
        TimelineView(.periodic(from: .now, by: 30)) { timeline in
            if isEditing {
                RuleEditorView(
                    mode: .edit(isEnabled: rule.isEnabled),
                    draft: RuleDraft(rule: rule),
                    onBack: { isEditing = false },
                    onCommit: { draft in
                        draft.apply(to: rule)
                        isEditing = false
                    },
                    onToggleEnabled: {
                        rule.isEnabled.toggle()
                        rule.pausedUntil = nil
                        isEditing = false
                    },
                    onDelete: {
                        pendingDeletion = true
                        dismiss()
                    }
                )
            } else {
                detail(now: timeline.date)
            }
        }
        .background(Theme.background)
        .onDisappear {
            if pendingDeletion {
                modelContext.delete(rule)
            }
        }
    }

    private func detail(now: Date) -> some View {
        let status = rule.status(at: now)
        return VStack(spacing: 0) {
            HStack {
                CircleIconButton(systemImage: "xmark") { dismiss() }
                    .accessibilityIdentifier("closeDetailButton")
                Spacer()
            }
            .padding(.horizontal, 20)
            .padding(.top, 18)

            ScrollView {
                VStack(spacing: 24) {
                    RuleIconPair(kind: rule.kind, isActive: status.isActive)
                    VStack(spacing: 6) {
                        Text("\(rule.kind.displayName), \(status.label(relativeTo: now))")
                            .font(.system(size: 13, weight: .medium))
                            .foregroundStyle(Theme.textSecondary)
                            .accessibilityIdentifier("detailStatusLabel")
                        Text(rule.name)
                            .font(.system(size: 26, weight: .bold))
                            .accessibilityIdentifier("detailRuleName")
                    }
                    detailRows
                }
                .padding(.horizontal, 20)
                .padding(.top, 8)
            }

            footer(now: now)
                .padding(.horizontal, 20)
                .padding(.bottom, 16)
        }
        .foregroundStyle(.white)
    }

    private var detailRows: some View {
        VStack(spacing: 0) {
            switch rule.kind {
            case .schedule:
                row("During this time", rule.schedule.timeRangeLabel)
                divider
                row("On these days", rule.days.summary)
                divider
                row(rule.selectionMode.displayName, appCountLabel)
                divider
                row("Adult websites", rule.blockAdultContent ? "Blocked" : "Allowed")
                divider
                row("Unblocks allowed", rule.hardMode ? "No" : "Yes")
            case .timeLimit:
                row("When I use", appCountLabel)
                divider
                row("For this long", "\(rule.dailyLimitMinutes)m daily")
                divider
                row("On these days", rule.days.summary)
                divider
                row("Then block until", "Tomorrow")
                divider
                row("Adult websites", rule.blockAdultContent ? "Blocked" : "Allowed")
                divider
                row("Unblocks allowed", rule.hardMode ? "No" : "Yes")
            case .openLimit:
                row("When I open", appCountLabel)
                divider
                row("More than", "\(rule.maxOpens) opens daily")
                divider
                row("On these days", rule.days.summary)
                divider
                row("Then block until", "Tomorrow")
                divider
                row("Adult websites", rule.blockAdultContent ? "Blocked" : "Allowed")
                divider
                row("Unblocks allowed", rule.hardMode ? "No" : "Yes")
            }
        }
        .background(Theme.surface, in: RoundedRectangle(cornerRadius: 18))
    }

    private var appCountLabel: String {
        rule.selectionCount == 1 ? "1 App" : "\(rule.selectionCount) Apps"
    }

    private func row(_ label: String, _ value: String) -> some View {
        HStack {
            Text(label)
                .font(.system(size: 15, weight: .medium))
            Spacer()
            Text(value)
                .font(.system(size: 15))
                .foregroundStyle(Theme.textSecondary)
        }
        .padding(.horizontal, 16)
        .padding(.vertical, 14)
        .accessibilityElement(children: .combine)
        .accessibilityIdentifier("detailRow-\(label)")
    }

    private var divider: some View {
        Divider().background(.white.opacity(0.06)).padding(.leading, 16)
    }

    @ViewBuilder
    private func footer(now: Date) -> some View {
        if RulePolicy.canEdit(rule, at: now) {
            Button {
                isEditing = true
            } label: {
                Label("Edit Rule", systemImage: "pencil")
                    .font(.system(size: 17, weight: .semibold))
                    .foregroundStyle(.black)
                    .frame(maxWidth: .infinity)
                    .frame(height: 54)
                    .background(.white, in: RoundedRectangle(cornerRadius: 27))
            }
            .buttonStyle(.plain)
            .accessibilityIdentifier("editRuleButton")
        } else {
            HStack(spacing: 10) {
                Image(systemName: "lock.fill")
                Text("Hard Mode is on — this rule is locked until the block ends.")
                    .font(.system(size: 14, weight: .medium))
            }
            .foregroundStyle(Theme.textSecondary)
            .frame(maxWidth: .infinity)
            .padding(.vertical, 16)
            .background(Theme.surface, in: RoundedRectangle(cornerRadius: 18))
            .accessibilityElement(children: .combine)
            .accessibilityIdentifier("hardModeLockedNotice")
        }
    }
}