//! Builds the "tail" of the docker command — everything after the image
//! name (entrypoint, model, args, auto-generated flags).

use crate::config::{Node, Recipe};
use crate::engine_flags::{EngineFlagsCtx, build_engine_args};

/// The subset of [`DockerCommandCtx`] that `build_tail` needs.
pub(crate) struct TailCtx<'a> {
    pub recipe: &'a Recipe,
    pub tp_size: u32,
    pub pp_size: u32,
    pub nnodes: u32,
    pub init_port: u16,
    pub master_ib_ip: &'a str,
}

/// Build the docker command tail — everything after the image name.
pub fn build_tail(ctx: &TailCtx<'_>, node: &Node) -> Vec<String> {
    let mut tail = Vec::new();

    // Entrypoint — from the recipe (e.g. ["vllm", "serve"]), returned raw.
    // Callers shell-quote the assembled command (Docker host side) or pass
    // to `build_mod_script` (which quotes each word for the container `-c`).
    if !ctx.recipe.entrypoint.is_empty() {
        tail.extend(ctx.recipe.entrypoint.clone());
    }

    // Shared engine args: model, recipe args, distributed flags, headless.
    let ectx = EngineFlagsCtx {
        recipe: ctx.recipe,
        tp_size: ctx.tp_size,
        pp_size: ctx.pp_size,
        nnodes: ctx.nnodes,
        init_port: ctx.init_port,
        master_ib_ip: ctx.master_ib_ip,
    };
    tail.extend(build_engine_args(&ectx, node));

    // Docker always binds --host 0.0.0.0 and --port.
    tail.push("--host".to_string());
    tail.push("0.0.0.0".to_string());
    tail.extend(["--port".into(), ctx.recipe.port.to_string()]);
    tail
}