//! The HTTP wire contract of filebrowser-ng in one place.
//!
//! Both the server (axum) and the web frontend (wasm `fetch`) import these
//! endpoint paths, query params and serde types, so the two sides cannot
//! drift apart. Serde only — no axum, no wasm dependencies.

use serde::{Deserialize, Serialize};

// ---------------------------------------------------------------------------
// Endpoint paths (single source of truth for the route table and the client)
// ---------------------------------------------------------------------------

pub const AUTH_LOGIN: &str = "/api/auth/login";
pub const AUTH_LOGOUT: &str = "/api/auth/logout";
pub const AUTH_ME: &str = "/api/auth/me";
pub const AUTH_SETUP: &str = "/api/auth/setup";
/// File operations: `{FILES}/{root_id}` and `{FILES}/{root_id}/{path...}`.
pub const FILES: &str = "/api/files";
/// Share management (authenticated): `{SHARES}` and `{SHARES}/{id}`.
pub const SHARES: &str = "/api/shares";
/// Public share resolve (no login): `{SHARE}/{token}`.
pub const SHARE: &str = "/api/share";
/// Suffix on `{SHARE}/{token}`: submit the password of a protected share.
pub const SHARE_UNLOCK_SUFFIX: &str = "/unlock";
/// `GET /api/search` — name and/or content search, streamed as SSE.
pub const SEARCH: &str = "/api/search";

/// WebDAV mount of the signed-in user's roots: `{DAV}` and `{DAV}/{path...}`.
pub const DAV: &str = "/dav";
/// WebDAV mount of one public share: `{DAV_SHARE}/{token}/{path...}`.
///
/// A separate top-level path, not a segment under [`DAV`]: there, the first
/// segment is a root's display name, which a reserved word could collide with.
pub const DAV_SHARE: &str = "/dav-share";

/// Admin user management: `{ADMIN_USERS}` and `{ADMIN_USERS}/{id}`.
pub const ADMIN_USERS: &str = "/api/admin/users";
pub const ADMIN_SETTINGS: &str = "/api/admin/settings";
/// Pseudo root id every signed-in admin has on the files API: the whole
/// server root, read-only (the admin folder picker browses it). Real root
/// ids are positive database ids. Not listed in `/me`.
pub const ADMIN_ROOT: i64 = -1;

// ---------------------------------------------------------------------------
// Query params
// ---------------------------------------------------------------------------

/// `?action=...` on file URLs; without it the route lists the directory.
pub const P_ACTION: &str = "action";
pub const ACTION_DOWNLOAD: &str = "download";
pub const ACTION_PREVIEW: &str = "preview";
pub const ACTION_CONTENT: &str = "content";
pub const ACTION_THUMB: &str = "thumb";
/// `POST {FILES}/...?action=mkdir` — create a folder. Explicit, because the
/// POST route also carries uploads and mutations.
pub const ACTION_MKDIR: &str = "mkdir";
/// `POST {FILES}/...?action=create-file` — create an empty file. Explicit
/// like `mkdir`, for the same reason.
pub const ACTION_CREATE_FILE: &str = "create-file";
/// `?format=...` for folder downloads (values: see `server::archive::ArchiveFormat`).
pub const P_FORMAT: &str = "format";
/// `?share=<token>` — authenticate file calls with a public share token.
pub const P_SHARE: &str = "share";
/// Search query text (`GET {SEARCH}`).
pub const P_Q: &str = "q";
/// Which index to search: `name`, `content` or `both`.
pub const P_SCOPE: &str = "scope";
/// Root id to search; omitted = the caller's first root.
pub const P_ROOT: &str = "root";
/// Folder inside the root to start a search in (relative to the root);
/// omitted or empty = the whole root.
pub const P_PATH: &str = "path";
/// `?overwrite=true|1` on mutations and uploads.
pub const P_OVERWRITE: &str = "overwrite";

// ---------------------------------------------------------------------------
// Wire enums
// ---------------------------------------------------------------------------

/// Access mode of a root or a share.
///
/// The serde names are also the values stored in the SQLite `mode` columns,
/// so renaming a variant would break existing databases. The round-trip test
/// below pins them.
#[derive(Serialize, Deserialize, Clone, Copy, Debug, PartialEq, Eq)]
#[serde(rename_all = "lowercase")]
pub enum Mode {
    Rw,
    Ro,
}

impl Mode {
    /// The only question callers ask: may this root be written to?
    pub fn is_writable(self) -> bool {
        matches!(self, Mode::Rw)
    }

    /// The wire/database spelling, for `<select>` values and SQL params.
    pub fn as_str(self) -> &'static str {
        match self {
            Mode::Rw => "rw",
            Mode::Ro => "ro",
        }
    }

    /// Parse the wire spelling. `None` for anything else.
    pub fn from_wire(s: &str) -> Option<Self> {
        match s {
            "rw" => Some(Mode::Rw),
            "ro" => Some(Mode::Ro),
            _ => None,
        }
    }
}

/// Which mutation [`Mutation`] asks for.
#[derive(Serialize, Deserialize, Clone, Copy, Debug, PartialEq, Eq)]
#[serde(rename_all = "lowercase")]
pub enum Op {
    Rename,
    Move,
    Copy,
}

// ---------------------------------------------------------------------------
// Request bodies (client → server)
// ---------------------------------------------------------------------------

#[derive(Serialize, Deserialize)]
pub struct Credentials {
    pub name: String,
    pub password: String,
}

/// Rename / move / copy (one body for all file mutations).
#[derive(Serialize, Deserialize)]
pub struct Mutation {
    pub op: Op,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub new_name: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub dst_root_id: Option<i64>,
    /// Destination directory, relative to `dst_root_id`.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub dst: Option<String>,
    #[serde(default)]
    pub overwrite: bool,
}

/// A user folder: path relative to the server root + access mode.
#[derive(Serialize, Deserialize)]
pub struct Root {
    /// Path relative to the server root; "." means the whole root.
    pub path: String,
    #[serde(default = "default_rw")]
    pub mode: Mode,
}

fn default_rw() -> Mode {
    Mode::Rw
}

#[derive(Serialize, Deserialize)]
pub struct CreateUser {
    pub name: String,
    pub password: String,
    #[serde(default)]
    pub is_admin: bool,
    #[serde(default)]
    pub roots: Vec<Root>,
}

#[derive(Serialize, Deserialize)]
pub struct UpdateUser {
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub password: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub is_admin: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub active: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub roots: Option<Vec<Root>>,
}

/// Server settings (GET/PUT `{ADMIN_SETTINGS}`).
#[derive(Serialize, Deserialize, Clone)]
pub struct Settings {
    pub allow_writable_shares: bool,
    /// Folders left out of every search, as paths relative to the server
    /// root. A path covers everything beneath it.
    #[serde(default)]
    pub search_excludes: Vec<String>,
}

#[derive(Serialize, Deserialize)]
pub struct CreateShare {
    pub root_id: i64,
    /// Item path relative to the root ("" or "." for the root itself).
    pub path: String,
    #[serde(default)]
    pub writable: bool,
    /// Absolute expiry as RFC 3339; absent = never.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub expires_at: Option<String>,
    /// Password the visitor must enter before the share opens; absent = none.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub password: Option<String>,
}

/// POST `{SHARE}/{token}/unlock` — the password for a protected share.
#[derive(Serialize, Deserialize)]
pub struct UnlockShare {
    pub password: String,
}

// ---------------------------------------------------------------------------
// Responses (server → client)
// ---------------------------------------------------------------------------

/// What a listing entry actually is, decided by the server from the file's
/// leading bytes (magic numbers via `infer`, plus a text/binary heuristic) —
/// not from its name. Drives the icon and the preview the client offers.
///
/// Deliberately coarse: this answers "which viewer opens this", not "what
/// exact format is it". Syntax highlighting still keys off the extension,
/// because `.h` is C or C++ and no amount of sniffing decides that.
#[derive(Serialize, Deserialize, Clone, Copy, Debug, PartialEq, Eq)]
#[serde(rename_all = "lowercase")]
pub enum FileKind {
    Dir,
    Image,
    Video,
    Audio,
    Pdf,
    Archive,
    /// Anything that decodes as text: source code, markup, config, plain text.
    Text,
    /// Recognized-but-not-viewable, or undecodable bytes.
    Binary,
}

#[derive(Serialize, Deserialize, Clone, Debug, PartialEq)]
pub struct Entry {
    pub name: String,
    pub is_dir: bool,
    pub size: u64,
    /// RFC 3339 UTC modification time.
    pub mtime: String,
    /// Content-sniffed kind (see [`FileKind`]).
    pub kind: FileKind,
}

#[derive(Serialize, Deserialize)]
pub struct FilesResp {
    pub entries: Vec<Entry>,
    /// True when the folder had more entries than `MAX_LIST_ENTRIES`.
    /// `entries` then holds only the first `MAX_LIST_ENTRIES` after sorting.
    #[serde(default)]
    pub truncated: bool,
}

/// Cap on entries in one directory listing.
pub const MAX_LIST_ENTRIES: usize = 10_000;

/// One streamed search result. Each is sent as one SSE event
/// (`data: <json>`), in the order found; the `done` event always ends the
/// stream.
#[derive(Serialize, Deserialize, Clone)]
#[serde(tag = "type", rename_all = "snake_case")]
pub enum SearchEvent {
    /// A file or folder whose name matched (scope `name`/`both`).
    File {
        root_id: i64,
        /// Path relative to the root, `/`-separated.
        path: String,
        size: u64,
        is_dir: bool,
        /// Sniffed the same way as a directory listing's, so the client can
        /// pick an icon and a viewer without a second guess at the name.
        kind: FileKind,
    },
    /// One matching line (scope `content`/`both`). `path` is relative to the
    /// root; `text` is the matched line, truncated to a fixed length.
    Match {
        root_id: i64,
        path: String,
        line: u64,
        text: String,
    },
    /// Stream finished. `stopped` is true when the client aborted before the
    /// search completed.
    Done {
        stopped: bool,
        files: usize,
        matches: usize,
        /// Files examined (walked) before the stream ended.
        scanned: usize,
        /// Files skipped for content search (over the size cap).
        skipped: usize,
        elapsed_ms: u64,
    },
}

#[derive(Serialize, Deserialize, Clone)]
pub struct UserInfo {
    pub id: i64,
    pub name: String,
    pub is_admin: bool,
    /// Profile setting: single click opens entries (off = click selects,
    /// double click opens).
    pub single_click_open: bool,
    /// Profile setting: show image and video thumbnails in the grid.
    pub thumbnails: bool,
    /// Preferred UI language tag ("en", "de", "fr"); None = follow the
    /// browser.
    pub language: Option<String>,
}

#[derive(Serialize, Deserialize, Clone)]
pub struct RootInfo {
    pub id: i64,
    pub name: String,
    pub path: String,
    pub mode: Mode,
}

/// GET `{AUTH_ME}`.
#[derive(Serialize, Deserialize, Clone)]
pub struct Me {
    /// True while no users exist yet (first-boot setup).
    pub first_boot: bool,
    /// None on first boot.
    pub user: Option<UserInfo>,
    pub roots: Vec<RootInfo>,
    pub allow_writable_shares: bool,
    /// Whether the server can make thumbnails at all (`--cache` is set).
    /// The profile setting is only offered when this is true.
    pub thumbnails_available: bool,
}

/// GET/POST `{SHARES}`, GET `{SHARE}/{token}`.
#[derive(Serialize, Deserialize, Clone)]
pub struct ShareInfo {
    pub id: i64,
    pub token: String,
    /// Display name (file/folder name, or the root's name for ".").
    pub name: String,
    pub is_file: bool,
    pub writable: bool,
    /// Path relative to the server root.
    pub target: String,
    /// RFC 3339 UTC creation time.
    pub created_at: String,
    /// RFC 3339 UTC expiry; None = never.
    pub expires_at: Option<String>,
    /// Synthetic root id to use in file API calls.
    pub root_id: i64,
    /// The file's kind for file shares (None for folder shares, and when
    /// not sniffed — the public resolve endpoint fills it in).
    pub kind: Option<FileKind>,
    /// Whether the share asks for a password. Never the password itself.
    #[serde(default)]
    pub has_password: bool,
}

/// GET/POST `{ADMIN_USERS}`, PUT `{ADMIN_USERS}/{id}`.
#[derive(Serialize, Deserialize, Clone)]
pub struct AdminUser {
    pub id: i64,
    pub name: String,
    pub is_admin: bool,
    pub active: bool,
    pub roots: Vec<RootInfo>,
}

/// Acknowledges a successful mutation. Carries nothing: the 2xx status is
/// the acknowledgement, so the body is the empty object.
#[derive(Serialize, Deserialize)]
pub struct OkResp {}

/// DELETE `{FILES}/...`: whether the removed item was a folder (the client
/// reports "folder deleted" vs "file deleted").
#[derive(Serialize, Deserialize)]
pub struct DeleteResp {
    pub is_dir: bool,
}

/// Upload success: how many files were written.
#[derive(Serialize, Deserialize)]
pub struct UploadResp {
    pub uploaded: usize,
}

/// PUT `?action=content` (editor save): the file's new mtime (unix seconds).
#[derive(Serialize, Deserialize)]
pub struct SaveResp {
    pub mtime: i64,
}

#[cfg(test)]
mod tests {
    use super::*;

    /// The serde spellings are the database values too, so they are pinned.
    #[test]
    fn mode_wire_format_is_rw_ro() {
        assert_eq!(serde_json::to_string(&Mode::Rw).unwrap(), "\"rw\"");
        assert_eq!(serde_json::to_string(&Mode::Ro).unwrap(), "\"ro\"");
        for m in [Mode::Rw, Mode::Ro] {
            let s = serde_json::to_string(&m).unwrap();
            assert_eq!(serde_json::from_str::<Mode>(&s).unwrap(), m);
            // `as_str`/`from_wire` must agree with serde.
            assert_eq!(s, format!("\"{}\"", m.as_str()));
            assert_eq!(Mode::from_wire(m.as_str()), Some(m));
        }
        assert_eq!(Mode::from_wire("both"), None);
        assert!(serde_json::from_str::<Mode>("\"both\"").is_err());
        assert!(Mode::Rw.is_writable());
        assert!(!Mode::Ro.is_writable());
    }

    #[test]
    fn op_wire_format() {
        assert_eq!(serde_json::to_string(&Op::Rename).unwrap(), "\"rename\"");
        assert_eq!(serde_json::to_string(&Op::Move).unwrap(), "\"move\"");
        assert_eq!(serde_json::to_string(&Op::Copy).unwrap(), "\"copy\"");
        for op in [Op::Rename, Op::Move, Op::Copy] {
            let s = serde_json::to_string(&op).unwrap();
            assert_eq!(serde_json::from_str::<Op>(&s).unwrap(), op);
        }
        assert!(serde_json::from_str::<Op>("\"explode\"").is_err());
    }

    #[test]
    fn mutation_round_trip_skips_absent_fields() {
        let m = Mutation {
            op: Op::Move,
            new_name: None,
            dst_root_id: Some(3),
            dst: Some("docs".into()),
            overwrite: true,
        };
        let s = serde_json::to_string(&m).unwrap();
        assert!(!s.contains("new_name"));
        let back: Mutation = serde_json::from_str(&s).unwrap();
        assert_eq!(back.dst_root_id, Some(3));
        assert_eq!(back.op, Op::Move);
    }

    #[test]
    fn mutation_defaults_missing_fields() {
        let m: Mutation = serde_json::from_str(r#"{"op":"rename","new_name":"a.txt"}"#).unwrap();
        assert!(!m.overwrite);
        assert_eq!(m.dst, None);
    }

    #[test]
    fn root_defaults_mode_to_rw() {
        let r: Root = serde_json::from_str(r#"{"path":"docs"}"#).unwrap();
        assert_eq!(r.mode, Mode::Rw);
    }

    #[test]
    fn me_round_trip() {
        let me = Me {
            first_boot: false,
            user: Some(UserInfo {
                id: 1,
                name: "admin".into(),
                is_admin: true,
                single_click_open: false,
                thumbnails: true,
                language: None,
            }),
            roots: vec![RootInfo {
                id: 1,
                name: "root".into(),
                path: ".".into(),
                mode: Mode::Rw,
            }],
            allow_writable_shares: false,
            thumbnails_available: true,
        };
        let s = serde_json::to_string(&me).unwrap();
        let back: Me = serde_json::from_str(&s).unwrap();
        assert_eq!(back.roots.len(), 1);
    }
}