//! Runic Gateway installer.
//!
//! Takes a working ServUO installation and connects it to a Runic Gateway website. The design of
//! record is `docs/installer/PLAN.md`; the operator-facing contract, written before this binary
//! existed, is `docs/installer/INSTALL.md`.
//!
//! **This build implements Phases 1 to 4** — the whole of what `INSTALL.md` describes: bundle
//! resolution, ServUO detection and validation, the overlay sync, the optional patch tier,
//! `install.json`, the uo-link sidecar and its service, the token handoff, and the day-two
//! commands `doctor`, `update` and `uninstall`.
//!
//! **`--game rust`** (module-rust phase 18, docs/modules/rust/PLAN.md §34) runs the same four verbs
//! for Rust servers, in [`rustgame`]: schema-2 Rust bundles, named instances, a Rust-Link sidecar
//! and service per instance, and the plugin placed for Oxide or Carbon. ServUO's pipeline, files
//! and record are untouched by it; ServUO bundles are now read at schema 2 with schema 1 as the
//! fallback ([`bundle::fetch`]).
//!
//! Exit codes: `0` success, `1` the run failed, `2` the arguments were unusable — the same
//! convention as the sidecar's CLI. `doctor` additionally uses `1` for a *completed* run that
//! found something broken, so it can be read by a monitoring script; a `⚠` row never does that.
//! `uninstall` does the same for a step it could not carry out — everything else was still removed.
//!
//! ## Why the library target is called `rgdeploy`
//!
//! Windows applies **UAC installer detection** to unsigned executables whose file name contains
//! `install`, `setup`, `update` or `patch`: it decides the program is a legacy installer and
//! demands elevation before the process starts. That is tolerable for the shipped binary, which
//! needs Administrator anyway and is documented as being run from an elevated shell — but Cargo
//! names test harnesses after their target, so a target called `runicgateway_installer` produces
//! `runicgateway_installer-<hash>.exe`, which Windows refuses to launch (`os error 740`) and
//! `cargo test` cannot run at all on a developer's machine.
//!
//! So the code lives in a neutrally-named library, the binary target keeps the published name from
//! PLAN.md §3, and `[[bin]] test = false` keeps Cargo from building a harness under the triggering
//! name. Nothing an operator sees changes.

pub mod backup;
pub mod bundle;
pub mod cli;
pub mod diff;
pub mod doctor;
pub mod install;
pub mod net;
pub mod overlay;
pub mod patch;
pub mod paths;
pub mod record;
pub mod rustgame;
pub mod service;
pub mod servuo;
pub mod sidecar;
pub mod tier;
pub mod ui;
pub mod uninstall;
pub mod update;
pub mod util;

use cli::{Command, Mode};

/// The whole program. Returns the process exit code rather than calling `exit` itself, so the
/// entry point stays a one-liner and this stays callable from a test.
pub fn run() -> i32 {
    ui::init_console();

    let parsed = match cli::parse(std::env::args().skip(1)) {
        Ok(parsed) => parsed,
        Err(message) => {
            eprintln!("error: {message}\n");
            eprint!("{}", cli::USAGE);
            return 2;
        }
    };

    // Every arm yields the process exit code, because one of them has more than two outcomes:
    // `doctor` completes successfully while reporting a broken deployment, and a monitoring script
    // has to be able to tell that from a healthy one (see `doctor::run`).
    let result: anyhow::Result<i32> = match parsed.mode {
        Mode::Help => {
            print!("{}", cli::USAGE);
            Ok(0)
        }
        Mode::Version => {
            println!("runicgateway-installer {}", env!("CARGO_PKG_VERSION"));
            Ok(0)
        }
        Mode::Run(command) if parsed.game == cli::Game::Rust => rustgame::run(&parsed, command),
        Mode::Run(Command::Install) => install::run(&parsed).map(|()| 0),
        Mode::Run(Command::Update) => update::run(&parsed).map(|()| 0),
        Mode::Run(Command::Doctor) => doctor::run(&parsed),
        Mode::Run(Command::Uninstall) => uninstall::run(&parsed),
    };

    match result {
        Ok(code) => code,
        Err(error) => {
            // The chain is printed, not just the outermost message: "cannot write
            // /etc/runicgateway/install.json" is only actionable with the OS error still attached.
            eprintln!("\nerror: {error}");
            for cause in error.chain().skip(1) {
                eprintln!("  caused by: {cause}");
            }
            1
        }
    }
}

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

    #[test]
    fn every_documented_command_has_an_implementation() {
        // The published contract is INSTALL.md §2's four commands. This build answers all of them,
        // so the parser and the dispatcher must not be able to drift apart — an unhandled arm here
        // used to be a "not implemented" message, and is now a compile error by construction.
        for command in [
            Command::Install,
            Command::Doctor,
            Command::Update,
            Command::Uninstall,
        ] {
            assert!(cli::USAGE.contains(&command.to_string()), "{command}");
        }
    }
}