import SwiftUI

struct ReleaseView: View {

    @State private var model: ReleaseDetailViewModel
    @State private var editing = false
    @State private var draftTitle = ""
    @State private var draftNotes = ""

    init(client: GitbayClient, repo: String, tag: String) {
        _model = State(initialValue: ReleaseDetailViewModel(
            client: client, repoPath: repo, tag: tag
        ))
    }

    var body: some View {
        List {
            if let release = model.state.value {
                if let error = model.actionError {
                    Section {
                        GBNotice(error, .gbWarn)
                    }
                }
                Section {
                    VStack(alignment: .leading, spacing: 6) {
                        Text(release.title.isEmpty ? release.tag : release.title)
                            .font(.gbSans(.headline))
                        HStack(spacing: 6) {
                            Text(release.tag)
                                .font(.gbMono(.caption))
                            if let author = release.author {
                                Text("by \(author)")
                            }
                            Text(release.createdAt, format: .relative(presentation: .named))
                                .foregroundStyle(.tertiary)
                        }
                        .font(.gbSans(.caption))
                        .foregroundStyle(.secondary)
                    }
                    .padding(.vertical, 2)
                }

                if let notes = release.notes, !notes.isEmpty {
                    Section {
                        MarkdownView(markdown: notes)
                            .padding(.vertical, 4)
                    }
                }

                if let assets = release.assets, !assets.isEmpty {
                    Section("Assets") {
                        ForEach(assets) { asset in
                            Link(destination: model.downloadURL(for: asset)) {
                                HStack {
                                    VStack(alignment: .leading, spacing: 2) {
                                        Text(asset.name)
                                            .font(.gbMono(.caption))
                                            .foregroundStyle(.primary)
                                            .lineLimit(1)
                                        Text(String(asset.sha256.prefix(16)))
                                            .font(.gbMono(.caption2))
                                            .foregroundStyle(.tertiary)
                                    }
                                    Spacer()
                                    Text(asset.size.formatted(.byteCount(style: .file)))
                                        .font(.gbSans(.caption))
                                        .foregroundStyle(.secondary)
                                    Image(systemName: "arrow.down.circle")
                                        .foregroundStyle(.secondary)
                                }
                            }
                        }
                    }
                }
            }
        }
        .overlay { LoadStateOverlay(state: model.state) }
        .navigationTitle(model.tag)
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItem(placement: .topBarTrailing) {
                if let release = model.state.value {
                    Button("Edit") {
                        draftTitle = release.title
                        draftNotes = release.notes ?? ""
                        editing = true
                    }
                    .disabled(model.working)
                    .accessibilityIdentifier("release-edit-button")
                }
            }
        }
        .sheet(isPresented: $editing) {
            ComposeSheet(
                heading: "Edit \(model.tag)",
                submitLabel: "Save",
                working: model.working,
                errorMessage: model.actionError,
                title: $draftTitle,
                bodyText: $draftNotes
            ) {
                Task {
                    await model.edit(title: draftTitle, notes: draftNotes)
                    if model.actionError == nil { editing = false }
                }
            }
        }
        .task { await model.load() }
        .refreshable { await model.load() }
    }
}