//! The editor's 9P surface. The wire protocol, the client, the transports
//! and the file-server engine (`cloud9.fs.Server`) live in cloud9; this
//! module names the two engine configurations Pardes builds, the editor's
//! and the board's, and re-exports what the transports and firmware use.
const cloud9 = @import("cloud9");
pub const fs = cloud9.fs;
pub const Server = cloud9.fs.Server;
pub const Error = cloud9.Error;
pub const Type = cloud9.Type;
pub const isT = cloud9.isT;
pub const header_len = cloud9.header_len;
pub const qid_len = cloud9.qid_len;
pub const stat_fixed = cloud9.stat_fixed;
pub const notag = cloud9.notag;
pub const nofid = cloud9.nofid;
pub const max_welem = cloud9.max_welem;
pub const iohdrsz = cloud9.iohdrsz;
pub const Qid = cloud9.Qid;
pub const Stat = cloud9.Stat;
pub const Msg = cloud9.Msg;
pub const Decoded = cloud9.Decoded;
pub const frameLen = cloud9.frameLen;
pub const encode = cloud9.encode;
pub const decode = cloud9.decode;
pub const qtdir = cloud9.qtdir;
pub const qtappend = cloud9.qtappend;
pub const qtexcl = cloud9.qtexcl;
pub const qtmount = cloud9.qtmount;
pub const qtauth = cloud9.qtauth;
pub const qttmp = cloud9.qttmp;
pub const qtfile = cloud9.qtfile;
pub const dmdir = cloud9.dmdir;
pub const dmappend = cloud9.dmappend;
pub const dmexcl = cloud9.dmexcl;
pub const dmmount = cloud9.dmmount;
pub const dmauth = cloud9.dmauth;
pub const dmtmp = cloud9.dmtmp;
pub const dmperm = cloud9.dmperm;
pub const Client = cloud9.Client;
pub const ClientError = cloud9.ClientError;
pub const max_tags = cloud9.max_tags;
pub const oread = cloud9.oread;
pub const owrite = cloud9.owrite;
pub const ordwr = cloud9.ordwr;
pub const oexec = cloud9.oexec;
pub const otrunc = cloud9.otrunc;
pub const ocexec = cloud9.ocexec;
pub const orclose = cloud9.orclose;
pub const errmax = cloud9.fs.errmax;
pub const errString = cloud9.fs.errString;
pub const msize_min = cloud9.fs.msize_min;

/// The smallest msize a native listener offers (src/9p_io.zig).
pub const min_msize: u32 = 4096;
/// What a native listener negotiates.
pub const msize: u32 = 65536;

/// The editor's engine: native fid count, native file names, and room to
/// park a write of any size a frame can carry -- a request that would change
/// a pane while the editor is out in a syscall waits in the engine
/// (src/9p_io.zig, `serve`), and a write it cannot keep would fail instead.
/// The largest write is msize less the Twrite header, 23 bytes (the test
/// below asks a client), one byte more than `iohdrsz` allows for.
/// Up to 128 reads held on one connection (a follower each of the log or
/// an event file); the next is refused `too many reads waiting: 128`. A
/// mount (9ns) keeps a wider window, 256, so held reads never take every
/// one of its workers.
pub const editor: cloud9.fs.Options = .{ .fid_capacity = max_fids, .name_capacity = 255, .park_data_max = msize - 23, .slot_capacity = max_held };

pub const max_held: usize = 128;
/// The board's engine: the GPIO firmware's budget (src/esp32p4_9p.zig).
pub const board: cloud9.fs.Options = .{ .fid_capacity = board_fids, .name_capacity = board_name_capacity };

pub const max_fids: usize = 256;
pub const board_fids: usize = 32;
pub const board_name_capacity: usize = 28;

const std = @import("std");
const testing = std.testing;

const Stub = struct {
    pub const Req = cloud9.fs.Req;
    pub const Reply = cloud9.fs.Reply;
};

test "9p server: the editor's engine can park the largest write a client sends" {
    var in: [4096]u8 = undefined;
    var out: [4096]u8 = undefined;
    var client: Client = .init(.{ .in = &in, .out = &out });
    client.msize = msize;
    try testing.expect(editor.park_data_max >= client.maxWrite());
}

test "9p server: board and native capacities size the actual fid storage" {
    const Board = Server(Stub, board);
    const Native = Server(Stub, editor);
    const BoardFids = @FieldType(Board, "fids");
    const NativeFids = @FieldType(Native, "fids");
    try testing.expectEqual(32, @typeInfo(BoardFids).array.len);
    try testing.expectEqual(256, @typeInfo(NativeFids).array.len);
    try testing.expectEqual(28, @sizeOf(@FieldType(Board.Fid, "name")));
    try testing.expectEqual(255, @sizeOf(@FieldType(Native.Fid, "name")));
    try testing.expectEqual(32 * @sizeOf(Board.Fid), @sizeOf(BoardFids));
    try testing.expectEqual(256 * @sizeOf(Native.Fid), @sizeOf(NativeFids));
    try testing.expect(@sizeOf(BoardFids) <= 3 * 1024);
    try testing.expect(@sizeOf(@FieldType(Board, "slots")) <= 8 * 1024);
    try testing.expect(3 * 4096 + @sizeOf(Board) <= 24 * 1024);
    try testing.expect(min_msize >= msize_min);
}