import SwiftUI

enum SybilAttachmentTone {
    case composer
    case user
    case assistant
}

struct SybilAttachmentListView: View {
    var attachments: [ChatAttachment]
    var tone: SybilAttachmentTone
    var onRemove: ((String) -> Void)? = nil

    var body: some View {
        VStack(alignment: .leading, spacing: 8) {
            ForEach(attachments) { attachment in
                Group {
                    if attachment.kind == .image {
                        imageCard(attachment)
                    } else {
                        textCard(attachment)
                    }
                }
            }
        }
    }

    @ViewBuilder
    private func imageCard(_ attachment: ChatAttachment) -> some View {
        VStack(alignment: .leading, spacing: 0) {
            if let image = SybilChatAttachmentSupport.image(for: attachment) {
                Image(uiImage: image)
                    .resizable()
                    .scaledToFill()
                    .frame(maxWidth: .infinity)
                    .frame(height: 180)
                    .clipped()
            } else {
                ZStack {
                    RoundedRectangle(cornerRadius: 14)
                        .fill(Color.black.opacity(0.18))
                    Image(systemName: "photo")
                        .font(.system(size: 22, weight: .medium))
                        .foregroundStyle(SybilTheme.textMuted)
                }
                .frame(height: 140)
            }

            HStack(alignment: .top, spacing: 10) {
                Image(systemName: "photo")
                    .font(.system(size: 13, weight: .semibold))
                    .foregroundStyle(titleColor.opacity(0.92))
                    .frame(width: 26, height: 26)
                    .background(
                        RoundedRectangle(cornerRadius: 8)
                            .fill(Color.white.opacity(0.06))
                            .overlay(
                                RoundedRectangle(cornerRadius: 8)
                                    .stroke(Color.white.opacity(0.08), lineWidth: 1)
                            )
                    )

                VStack(alignment: .leading, spacing: 2) {
                    Text(attachment.filename)
                        .font(.sybil(.footnote, weight: .medium))
                        .foregroundStyle(titleColor)
                        .lineLimit(1)

                    Text(attachment.mimeType)
                        .font(.sybil(.caption2))
                        .foregroundStyle(SybilTheme.textMuted)
                        .lineLimit(1)
                }

                Spacer(minLength: 0)

                if let onRemove {
                    removeButton(for: attachment.id, onRemove: onRemove)
                }
            }
            .padding(12)
        }
        .background(cardBackground)
        .clipShape(RoundedRectangle(cornerRadius: 14))
        .overlay(
            RoundedRectangle(cornerRadius: 14)
                .stroke(cardBorder, lineWidth: 1)
        )
    }

    @ViewBuilder
    private func textCard(_ attachment: ChatAttachment) -> some View {
        VStack(alignment: .leading, spacing: 10) {
            HStack(alignment: .top, spacing: 10) {
                Image(systemName: "doc.text")
                    .font(.system(size: 13, weight: .semibold))
                    .foregroundStyle(titleColor.opacity(0.92))
                    .frame(width: 26, height: 26)
                    .background(
                        RoundedRectangle(cornerRadius: 8)
                            .fill(Color.white.opacity(0.06))
                            .overlay(
                                RoundedRectangle(cornerRadius: 8)
                                    .stroke(Color.white.opacity(0.08), lineWidth: 1)
                            )
                    )

                VStack(alignment: .leading, spacing: 2) {
                    Text(attachment.filename)
                        .font(.sybil(.footnote, weight: .medium))
                        .foregroundStyle(titleColor)
                        .lineLimit(1)

                    Text(
                        attachment.truncated == true
                            ? "\(attachment.mimeType) • truncated"
                            : attachment.mimeType
                    )
                    .font(.sybil(.caption2))
                    .foregroundStyle(SybilTheme.textMuted)
                    .lineLimit(1)
                }

                Spacer(minLength: 0)

                if let onRemove {
                    removeButton(for: attachment.id, onRemove: onRemove)
                }
            }

            Text(SybilChatAttachmentSupport.previewText(for: attachment))
                .font(.system(.caption, design: .monospaced))
                .foregroundStyle(bodyColor)
                .frame(maxWidth: .infinity, alignment: .leading)
                .padding(10)
                .background(
                    RoundedRectangle(cornerRadius: 10)
                        .fill(Color.black.opacity(0.16))
                        .overlay(
                            RoundedRectangle(cornerRadius: 10)
                                .stroke(Color.white.opacity(0.05), lineWidth: 1)
                        )
                )
        }
        .padding(12)
        .background(cardBackground)
        .clipShape(RoundedRectangle(cornerRadius: 14))
        .overlay(
            RoundedRectangle(cornerRadius: 14)
                .stroke(cardBorder, lineWidth: 1)
        )
    }

    private func removeButton(for attachmentID: String, onRemove: @escaping (String) -> Void) -> some View {
        Button {
            onRemove(attachmentID)
        } label: {
            Image(systemName: "xmark")
                .font(.system(size: 11, weight: .bold))
                .foregroundStyle(SybilTheme.textMuted)
                .frame(width: 24, height: 24)
                .background(
                    Circle()
                        .fill(Color.white.opacity(0.06))
                )
        }
        .buttonStyle(.plain)
        .accessibilityLabel("Remove attachment")
    }

    private var cardBackground: some ShapeStyle {
        switch tone {
        case .composer:
            return AnyShapeStyle(
                LinearGradient(
                    colors: [SybilTheme.surface.opacity(0.86), SybilTheme.surfaceStrong.opacity(0.78)],
                    startPoint: .topLeading,
                    endPoint: .bottomTrailing
                )
            )
        case .user:
            return AnyShapeStyle(Color.black.opacity(0.14))
        case .assistant:
            return AnyShapeStyle(
                LinearGradient(
                    colors: [SybilTheme.surface.opacity(0.58), SybilTheme.surfaceStrong.opacity(0.42)],
                    startPoint: .topLeading,
                    endPoint: .bottomTrailing
                )
            )
        }
    }

    private var cardBorder: Color {
        switch tone {
        case .composer:
            return SybilTheme.border.opacity(0.82)
        case .user:
            return Color.white.opacity(0.12)
        case .assistant:
            return SybilTheme.border.opacity(0.58)
        }
    }

    private var titleColor: Color {
        switch tone {
        case .composer, .assistant:
            return SybilTheme.text
        case .user:
            return SybilTheme.text
        }
    }

    private var bodyColor: Color {
        switch tone {
        case .composer, .assistant:
            return SybilTheme.text.opacity(0.94)
        case .user:
            return SybilTheme.text.opacity(0.96)
        }
    }
}