import SwiftUI

/// One commit: what it says, who signed it, whether it passed, and what
/// it changed.
struct CommitView: View {

    @State private var model: CommitDetailViewModel

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

    var body: some View {
        List {
            if let commit = model.state.value {
                Section {
                    VStack(alignment: .leading, spacing: 6) {
                        Text(commit.subject)
                            .font(.gbSans(.headline))
                        if let message = commit.message,
                           !message.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
                            Text(message.trimmingCharacters(in: .whitespacesAndNewlines))
                                .font(.gbSans(.subheadline))
                                .foregroundStyle(.secondary)
                        }
                        HStack(spacing: 6) {
                            Text(commit.shortSHA)
                                .font(.gbMono(.caption))
                                .foregroundStyle(.secondary)
                            SignatureBadge(signature: commit.signature)
                        }
                        HStack(spacing: 6) {
                            Text(commit.authorName)
                            Text(commit.date, format: .dateTime.year().month().day())
                                .foregroundStyle(.tertiary)
                        }
                        .font(.gbSans(.caption))
                        .foregroundStyle(.secondary)
                    }
                    .padding(.vertical, 2)
                }

                if let checks = commit.checks, !checks.isEmpty {
                    Section("Checks") {
                        ForEach(checks) { check in
                            HStack {
                                Image(systemName: check.state == "success"
                                      ? "checkmark.circle.fill"
                                      : check.state == "pending" ? "circle.dotted" : "xmark.circle.fill")
                                    .foregroundStyle(check.state == "success"
                                                     ? Color.gbOK
                                                     : check.state == "pending" ? Color.gbWarn : Color.gbBad)
                                Text(check.context)
                                    .font(.gbSans(.subheadline))
                                Spacer()
                                Text(check.state)
                                    .font(.gbSans(.caption))
                                    .foregroundStyle(.secondary)
                            }
                        }
                    }
                }

                if let diff = model.diff, !diff.files.isEmpty {
                    Section("Changes +\(diff.additions) −\(diff.deletions)") {
                        ForEach(diff.files) { file in
                            NavigationLink(value: RepoRoute.file(
                                repo: model.repoPath, path: file.displayPath, ref: commit.sha
                            )) {
                                HStack {
                                    Text(file.displayPath)
                                        .font(.gbMono(.caption))
                                        .lineLimit(1)
                                        .truncationMode(.head)
                                    Spacer()
                                    Text("+\(file.additions)").foregroundStyle(Color.gbOK)
                                    Text("−\(file.deletions)").foregroundStyle(Color.gbBad)
                                }
                                .font(.gbSans(.caption2))
                            }
                        }
                    }
                }
            }
        }
        .overlay { LoadStateOverlay(state: model.state) }
        .navigationTitle(String(model.sha.prefix(10)))
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItem(placement: .topBarTrailing) {
                if model.diff?.files.isEmpty == false {
                    NavigationLink(value: RepoRoute.commitDiff(
                        repo: model.repoPath, sha: model.sha
                    )) {
                        Image(systemName: "plus.forwardslash.minus")
                    }
                    .accessibilityIdentifier("commit-diff-button")
                }
            }
        }
        .task { await model.load() }
        .refreshable { await model.load() }
    }
}

/// The commit's patch, rendered by the same view the MR diff uses.
struct CommitDiffView: View {

    @State private var model: CommitDetailViewModel

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

    var body: some View {
        ZStack {
            Color.clear
            if let diff = model.diff, !diff.files.isEmpty {
                List {
                    ForEach(diff.files) { file in
                        DiffFileSection(file: file)
                    }
                }
                .listStyle(.plain)
            }
        }
        .overlay { LoadStateOverlay(state: model.state) }
        .navigationTitle("Diff")
        .navigationBarTitleDisplayMode(.inline)
        .task { await model.load() }
    }
}