import SwiftUI

/// A user or organization: who they are, who they work with, what they
/// have been doing, and what they own that you can see.
struct ProfileView: View {

    @State private var model: ProfileViewModel

    /// Someone else's profile is titled with their name. Your own is
    /// reached from a tab and titled to match it.
    private let title: String?

    init(client: GitbayClient, name: String, title: String? = nil) {
        _model = State(initialValue: ProfileViewModel(client: client, name: name))
        self.title = title
    }

    var body: some View {
        List {
            if let profile = model.state.value {
                header(profile)
                peopleSection(profile)
                activitySection(profile)
                reposSection(profile)
                if profile.isOrg {
                    Section {
                        NavigationLink(value: OrgRoute.org(profile.name)) {
                            Label("Members & Teams", systemImage: "person.3")
                        }
                    }
                }
            }
        }
        .overlay { LoadStateOverlay(state: model.state) }
        .navigationTitle(title ?? model.name)
        .navigationBarTitleDisplayMode(.inline)
        .task { await model.load() }
        .refreshable { await model.load() }
    }

    // MARK: - Sections

    private func header(_ profile: ProfileViewModel.Profile) -> some View {
        Section {
            VStack(alignment: .leading, spacing: 8) {
                HStack(spacing: 8) {
                    Image(systemName: profile.isOrg ? "building.2" : "person.crop.circle")
                        .font(.gbSans(.title2))
                        .foregroundStyle(Color.gbAccent)
                    Text(profile.name)
                        .font(.gbSans(.title3).weight(.semibold))
                    GBChip(profile.kind, .secondary)
                }
                if let description = profile.description, !description.isEmpty {
                    Text(description)
                        .font(.gbSans(.subheadline))
                        .foregroundStyle(.secondary)
                }
                if let website = profile.website, !website.isEmpty,
                   let url = URL(string: website) {
                    Link(destination: url) {
                        Label(website, systemImage: "link")
                            .font(.gbSans(.caption))
                            .lineLimit(1)
                    }
                }
            }
            .padding(.vertical, 4)
        }
    }

    /// A user's organizations, or an organization's members — either way,
    /// who they work with, each one openable.
    @ViewBuilder
    private func peopleSection(_ profile: ProfileViewModel.Profile) -> some View {
        let people = profile.isOrg ? (profile.members ?? []) : (profile.orgs ?? [])
        if !people.isEmpty {
            Section(profile.isOrg ? "Members" : "Organizations") {
                ForEach(people) { person in
                    NavigationLink(value: RepoRoute.profile(person.name)) {
                        HStack {
                            Label(person.name, systemImage: profile.isOrg
                                  ? "person.crop.circle" : "building.2")
                                .font(.gbSans(.subheadline))
                            Spacer()
                            if let role = person.role, !role.isEmpty {
                                GBChip(role, .secondary)
                            }
                        }
                    }
                }
            }
        }
    }

    @ViewBuilder
    private func activitySection(_ profile: ProfileViewModel.Profile) -> some View {
        if let activity = profile.activity, !activity.isEmpty {
            Section {
                ActivityGraph(days: activity)
            } header: {
                Text("Activity")
            } footer: {
                Text("\(profile.activityTotal) contributions in the last year.")
            }
        }
    }

    private func reposSection(_ profile: ProfileViewModel.Profile) -> some View {
        Section("Repositories \(profile.repos.count)") {
            if profile.repos.isEmpty {
                Text("No visible repositories.")
                    .font(.gbSans(.subheadline))
                    .foregroundStyle(.secondary)
            } else {
                ForEach(profile.repos) { repo in
                    NavigationLink(value: RepoRoute.repo(repo.path)) {
                        VStack(alignment: .leading, spacing: 3) {
                            HStack(spacing: 6) {
                                Text(repo.name)
                                    .font(.gbSans(.subheadline).weight(.medium))
                                if repo.isPrivate {
                                    Image(systemName: "lock.fill")
                                        .font(.gbSans(.caption2))
                                        .foregroundStyle(.secondary)
                                }
                                if repo.isArchived {
                                    GBChip("archived", .secondary)
                                }
                            }
                            if let description = repo.description, !description.isEmpty {
                                Text(description)
                                    .font(.gbSans(.caption))
                                    .foregroundStyle(.secondary)
                                    .lineLimit(2)
                            }
                        }
                    }
                }
            }
        }
    }
}