use axum::{
    body::Body,
    extract::Request,
    http::{HeaderValue, StatusCode},
    middleware,
    response::IntoResponse,
    Extension,
};
use base64::Engine as _;
use clap::Subcommand;
use dav_server::DavHandler;
use std::path::PathBuf;

#[derive(Subcommand)]
pub enum WebdavCommand {
    #[command(name = "webdav-start")]
    Start {
        #[arg(short, long, default_value = "8002")]
        port: u16,
        #[arg(short, long)]
        user: String,
        #[arg(long, help = "Enable SQLite virtual directory mode")]
        virtual_mode: bool,
        #[arg(long, help = "SQLite database path for virtual directories")]
        db: Option<String>,
    },

    #[command(name = "webdav-folder")]
    Folder {
        #[arg(long, help = "Action: add, remove")]
        action: String,
        #[arg(long, help = "Virtual folder name (e.g. photos)")]
        name: String,
        #[arg(long, help = "Description for the folder")]
        description: Option<String>,
        #[arg(long, default_value = "data/webdav_virtual.sqlite")]
        db: String,
    },

    #[command(name = "webdav-tag")]
    Tag {
        #[arg(long, help = "Filename to tag (relative to root)")]
        file: String,
        #[arg(long, help = "Tag name (= virtual folder name)")]
        tag: String,
        #[arg(long, default_value = "data/webdav_virtual.sqlite")]
        db: String,
    },

    #[command(name = "webdav-untag")]
    Untag {
        #[arg(long, help = "Filename to untag")]
        file: String,
        #[arg(long, help = "Tag name to remove")]
        tag: String,
        #[arg(long, default_value = "data/webdav_virtual.sqlite")]
        db: String,
    },

    #[command(name = "webdav-list")]
    List {
        #[arg(long, help = "List folders, or files in a folder")]
        what: Option<String>,
        #[arg(long, help = "Folder name (for listing files in a folder)")]
        folder: Option<String>,
        #[arg(long, help = "Filename (for listing tags of a file)")]
        file: Option<String>,
        #[arg(long, default_value = "data/webdav_virtual.sqlite")]
        db: String,
    },
}

pub async fn handle_webdav_command(cmd: WebdavCommand) -> anyhow::Result<()> {
    match cmd {
        WebdavCommand::Start {
            port,
            user,
            virtual_mode,
            db,
        } => {
            let username = user.split(':').next().unwrap_or(&user).to_string();
            let password = user.split(':').nth(1).map(|s| s.to_string());

            let default_root = format!("/Users/accusys/momentry/var/sftpgo/data/{}", username);
            let home_dir = PathBuf::from(
                std::env::var("MB_WEBDAV_ROOT").unwrap_or(default_root),
            );

            if !home_dir.exists() {
                return Err(anyhow::anyhow!(
                    "User home directory not found: {}",
                    home_dir.display()
                ));
            }

            println!("=== MarkBase WebDAV Server (VFS) ===");
            println!("User: {}", username);
            if password.is_some() {
                println!("Auth: password protected");
            }
            println!("Port: {}", port);
            println!("Home: {}", home_dir.display());
            if virtual_mode {
                let db_path = db.clone().unwrap_or_else(|| "data/webdav_virtual.sqlite".to_string());
                println!("Virtual mode: enabled (db: {})", db_path);
            }
            println!();

            run_webdav_server(port, home_dir, username, password, virtual_mode, db).await?;
        }

        WebdavCommand::Folder {
            action,
            name,
            description,
            db,
        } => {
            let vfs = crate::vfs::virtual_fs::VirtualFs::new(&db, PathBuf::from("/tmp"))?;
            let folder = if name.starts_with('/') {
                name
            } else {
                format!("/{}", name)
            };
            match action.as_str() {
                "add" => {
                    let desc = description.unwrap_or_default();
                    vfs.add_folder(&folder, &desc)?;
                    println!("Added virtual folder: {} ({})", folder, desc);
                }
                "remove" => {
                    vfs.remove_folder(&folder)?;
                    println!("Removed virtual folder: {}", folder);
                }
                _ => {
                    return Err(anyhow::anyhow!("Unknown action: {} (use add or remove)", action));
                }
            }
        }

        WebdavCommand::Tag { file, tag, db } => {
            let vfs = crate::vfs::virtual_fs::VirtualFs::new(&db, PathBuf::from("/tmp"))?;
            vfs.tag_file(&file, &tag)?;
            println!("Tagged '{}' with '{}'", file, tag);
        }

        WebdavCommand::Untag { file, tag, db } => {
            let vfs = crate::vfs::virtual_fs::VirtualFs::new(&db, PathBuf::from("/tmp"))?;
            vfs.untag_file(&file, &tag)?;
            println!("Untagged '{}' from '{}'", file, tag);
        }

        WebdavCommand::List {
            what,
            folder,
            file,
            db,
        } => {
            let vfs = crate::vfs::virtual_fs::VirtualFs::new(&db, PathBuf::from("/tmp"))?;
            match what.as_deref() {
                Some("folders") | None => {
                    let folders = vfs.list_folders()?;
                    if folders.is_empty() {
                        println!("No virtual folders.");
                    } else {
                        println!("{:<30} {}", "Folder", "Description");
                        println!("{}", "-".repeat(60));
                        for (f, d) in folders {
                            println!("{:<30} {}", f, d);
                        }
                    }
                }
                Some("files") => {
                    let folder_name = folder.ok_or_else(|| anyhow::anyhow!("--folder required for listing files"))?;
                    let files = vfs.list_files_in_folder(&folder_name)?;
                    if files.is_empty() {
                        println!("No files in folder '{}'", folder_name);
                    } else {
                        println!("Files in folder '{}':", folder_name);
                        for f in files {
                            println!("  {}", f);
                        }
                    }
                }
                Some("tags") => {
                    let filename = file.ok_or_else(|| anyhow::anyhow!("--file required for listing tags"))?;
                    let tags = vfs.list_tags_for_file(&filename)?;
                    if tags.is_empty() {
                        println!("No tags for file '{}'", filename);
                    } else {
                        println!("Tags for file '{}':", filename);
                        for t in tags {
                            println!("  {}", t);
                        }
                    }
                }
                Some(other) => {
                    return Err(anyhow::anyhow!("Unknown list type: {} (use folders, files, or tags)", other));
                }
            }
        }
    }
    Ok(())
}

async fn run_webdav_server(
    port: u16,
    home_dir: PathBuf,
    user: String,
    password: Option<String>,
    virtual_mode: bool,
    db: Option<String>,
) -> anyhow::Result<()> {
    use axum::{routing::any, Router};
    use tokio::net::TcpListener;

    let dav_handler = if virtual_mode {
        let db_path = db.unwrap_or_else(|| "data/webdav_virtual.sqlite".to_string());
        let vfs = crate::vfs::virtual_fs::VirtualFs::new(&db_path, home_dir.clone())?;

        let folders = vfs.list_folders().unwrap_or_default();
        println!("Virtual folders ({}):", folders.len());
        for (f, d) in &folders {
            println!("  {} - {}", f, d);
        }
        println!("Default root: {}", home_dir.display());
        println!();
        let vfs_boxed: Box<dyn crate::vfs::VfsBackend> = Box::new(vfs);
        crate::webdav::create_webdav_handler_virtual(vfs_boxed, PathBuf::from("/"), None, user.clone())
    } else {
        let vfs = Box::new(crate::vfs::local_fs::LocalFs::new());
        crate::webdav::create_webdav_handler(vfs, home_dir.clone(), None, user.clone())
    };

    async fn webdav_auth_middleware(
        req: Request,
        next: middleware::Next,
    ) -> impl IntoResponse {
        let expected = req.extensions().get::<crate::webdav::WebdavCredentials>().cloned();

        let auth = req
            .headers()
            .get("Authorization")
            .and_then(|v| v.to_str().ok())
            .filter(|v| v.starts_with("Basic "))
            .and_then(|v| {
                let encoded = &v[6..];
                let decoded = base64::engine::general_purpose::STANDARD
                    .decode(encoded)
                    .ok()?;
                let creds = String::from_utf8(decoded).ok()?;
                let colon = creds.find(':')?;
                Some((creds[..colon].to_string(), creds[colon + 1..].to_string()))
            });

        let valid = match (auth, expected) {
            (Some((u, p)), Some(exp)) => {
                u == exp.username && exp.password.as_ref().map_or(true, |exp_p| p == *exp_p)
            }
            _ => false,
        };

        if !valid {
            return (
                StatusCode::UNAUTHORIZED,
                [(
                    "WWW-Authenticate",
                    HeaderValue::from_static("Basic realm=\"MarkBase WebDAV\""),
                )],
                Body::from("Unauthorized"),
            )
                .into_response();
        }

        next.run(req).await
    }

    let app = Router::new()
        .route("/", any(handle_dav))
        .route("/*path", any(handle_dav))
        .layer(Extension(dav_handler))
        .layer(middleware::from_fn(webdav_auth_middleware))
        .layer(Extension(crate::webdav::WebdavCredentials {
            username: user.clone(),
            password,
        }));

    let addr = format!("0.0.0.0:{}", port);
    let listener = TcpListener::bind(&addr).await?;

    println!("WebDAV server listening on http://{}", addr);
    println!("User: {}", user);
    if virtual_mode {
        println!("Mode: Virtual (SQLite tag-based)");
    } else {
        println!("Mode: Local");
    }
    println!();
    println!("Press Ctrl+C to stop");

    axum::serve(listener, app).await?;

    Ok(())
}

async fn handle_dav(
    Extension(dav): Extension<DavHandler>,
    Extension(_creds): Extension<crate::webdav::WebdavCredentials>,
    req: Request,
) -> impl IntoResponse {
    dav.handle(req).await
}