//! The `doctor` command — diagnose an existing deployment end to end.
//!
//! PLAN.md §5 Phase 4 calls this "the command that makes the whole thing supportable", and the row
//! that carries the phase is the last one: **has a shard actually dialed in?** Everything else can
//! be true — files copied, service running, hashes matching — while the bridge does nothing at all,
//! because ServUO shells out to `dotnet build`, prints the output, ignores the exit code and reloads
//! the previous `Scripts.dll` (§2.1). A clean boot is not evidence. `plugin_connected` is.
//!
//! Three rules shape this module:
//!
//! - **It writes nothing, anywhere.** Not to the ServUO tree, not to `install.json`, not to the
//!   sidecar's config. That is why `--print-config` is run only when the config file already
//!   exists: that flag *provisions* (it writes the file and mints a token when absent), so calling
//!   it on a host that has none would have `doctor` create the very state it is reporting on.
//! - **It asks the thing itself, not the record.** The installed binary answers `--version` and
//!   `--print-config`; the service manager answers `is-active`; the sidecar answers `/health`. The
//!   record says what `install` *did*, which is a different question from what is true now — and
//!   the gap between those two is the whole reason to run this.
//! - **A missing answer is a row, not an exception.** A host with no route to Gitea, a sidecar that
//!   is down, a config this process cannot read: each degrades to one honest line and the report
//!   still prints. The exit code is what a monitoring script reads — `1` if any row failed — and it
//!   is deliberately not raised by a `⚠`, which means "worth knowing", not "broken".
//!
//! The token is never printed here. `--print-config` returns it (it is one document), and this
//! module reads the paths, the bind and the protocol out of that document and drops the rest.

use std::path::{Path, PathBuf};
use std::time::Duration;

use anyhow::Result;
use serde::Deserialize;

use crate::cli::Cli;
use crate::record::{InstallRecord, LinkRecord};
use crate::servuo::ServUoRoot;
use crate::{bundle, net, patch, paths, servuo, sidecar, ui};

/// Both network calls give up quickly. Every row here is context around local state, so a host with
/// no route out must produce its report seconds later rather than appear to hang.
const BUNDLE_TIMEOUT: Duration = Duration::from_secs(15);
const HEALTH_TIMEOUT: Duration = Duration::from_secs(5);

/// The verdict on one row.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Mark {
    Ok,
    Warn,
    Fail,
}

impl Mark {
    fn glyph(self) -> &'static str {
        match self {
            Self::Ok => "✓",
            Self::Warn => "⚠",
            Self::Fail => "✗",
        }
    }
}

/// One line of the report, plus any detail lines that belong underneath it.
#[derive(Debug, Clone)]
pub struct Row {
    pub mark: Mark,
    pub label: String,
    pub detail: String,
    pub notes: Vec<String>,
}

impl Row {
    fn new(mark: Mark, label: &str, detail: impl Into<String>) -> Self {
        Self {
            mark,
            label: label.to_string(),
            detail: detail.into(),
            notes: Vec::new(),
        }
    }

    fn ok(label: &str, detail: impl Into<String>) -> Self {
        Self::new(Mark::Ok, label, detail)
    }

    fn warn(label: &str, detail: impl Into<String>) -> Self {
        Self::new(Mark::Warn, label, detail)
    }

    fn fail(label: &str, detail: impl Into<String>) -> Self {
        Self::new(Mark::Fail, label, detail)
    }

    fn note(mut self, note: impl Into<String>) -> Self {
        self.notes.push(note.into());
        self
    }

    fn notes_from(mut self, notes: impl IntoIterator<Item = String>) -> Self {
        self.notes.extend(notes);
        self
    }
}

/// Runs every check and prints the report. The `i32` is the process exit code.
pub fn run(cli: &Cli) -> Result<i32> {
    let layout = paths::layout();
    let record_path = layout.install_record();

    println!(
        "\nRunic Gateway installer {} — doctor",
        env!("CARGO_PKG_VERSION")
    );

    let Some(record) = InstallRecord::load(&record_path)? else {
        // Not an error in the `anyhow` sense — the command ran fine and the answer is "nothing is
        // installed here". Exit 1 all the same, because a monitoring script asking after a
        // deployment on this host has had its question answered in the negative.
        println!();
        ui::warn(&format!(
            "No deployment is recorded on this host.\n  \
             Looked for {}\n  \
             Run `install` first. If you installed with {} set, set it again for this run.",
            record_path.display(),
            paths::STATE_DIR_ENV
        ));
        return Ok(1);
    };

    let mut rows = vec![Row::ok(
        "Install record",
        format!(
            "{}  (bundle {}, installer {}, {})",
            record_path.display(),
            record.bundle.tag,
            record.installer.version,
            record.updated
        ),
    )];

    // ── ServUO and the overlay ───────────────────────────────────────────────
    let root = open_root(cli, &record);
    rows.push(servuo_row(&record, root.as_ref()));
    rows.push(overlay_row(&record, root.as_ref()));
    rows.push(patch_row(&record, root.as_ref(), &layout));

    // ── The sidecar ──────────────────────────────────────────────────────────
    // Asking the installed binary is what makes these rows describe the sidecar that will actually
    // answer the website, rather than the one the record believes was installed.
    let link = record.link_record();
    let live = link.as_ref().and_then(live_config);
    let health = live.as_ref().and_then(|doc| health_of(&doc.web.bind));

    rows.push(link_row(link.as_ref(), live.as_ref()));
    rows.push(service_row(link.as_ref()));
    rows.push(reachable_row(live.as_ref(), health.as_ref()));
    rows.push(protocol_row(&record, live.as_ref(), health.as_ref()));
    rows.push(shard_row(root.as_ref(), health.as_ref()));

    // ── The bundle ───────────────────────────────────────────────────────────
    rows.push(bundle_row(&record));

    // ── Backups ──────────────────────────────────────────────────────────────
    rows.push(backup_row(&layout));

    // ── Report ───────────────────────────────────────────────────────────────
    println!();
    for row in &rows {
        println!("{} {:<24} {}", row.mark.glyph(), row.label, row.detail);
        for note in &row.notes {
            println!("    {note}");
        }
    }

    let failed = rows.iter().filter(|r| r.mark == Mark::Fail).count();
    let warned = rows.iter().filter(|r| r.mark == Mark::Warn).count();
    println!();
    match (failed, warned) {
        (0, 0) => println!("Everything checks out."),
        (0, w) => println!("{w} thing(s) worth knowing about, nothing broken."),
        (f, _) => println!(
            "{f} check(s) failed. Start with the first ✗ above; \
             INSTALL.md's Troubleshooting table is keyed to these symptoms."
        ),
    }
    Ok(if failed > 0 { 1 } else { 0 })
}

/// The ServUO root to inspect: `--servuo` if given, else the one the record names.
///
/// [`servuo::open`] rather than `open_stopped`: a running shard is the *expected* state for a
/// diagnosis — it is the only state in which the shard-connected row can be true — and refusing to
/// report on a live host would make this command useless exactly when it is needed.
fn open_root(cli: &Cli, record: &InstallRecord) -> Result<ServUoRoot> {
    let path = cli
        .servuo
        .clone()
        .unwrap_or_else(|| record.servuo.path.clone());
    servuo::open(Path::new(&path))
}

fn servuo_row(record: &InstallRecord, root: Result<&ServUoRoot, &anyhow::Error>) -> Row {
    let root = match root {
        Ok(root) => root,
        Err(error) => {
            return Row::fail("ServUO found", record.servuo.path.clone())
                .note(error.to_string().replace('\n', " "))
        }
    };

    let row = Row::ok(
        "ServUO found",
        format!("{}  ({})", root.path.display(), root.version_display()),
    );
    // A tree that has been upgraded under an install is the single most useful thing this row can
    // say: the patch tier was resolved against the version recorded here, not against this one.
    match &record.servuo.version {
        Some(recorded) if Some(recorded) != root.version.as_ref() => Row::warn(
            "ServUO found",
            format!("{}  ({})", root.path.display(), root.version_display()),
        )
        .note(format!(
            "this tree was {recorded} when Runic Gateway was installed — re-check the patch tier \
             below"
        )),
        _ if !root.is_supported_version() => row.note(format!(
            "{} is the only supported version; the base overlay is expected to work anyway",
            servuo::SUPPORTED_VERSION
        )),
        _ => row,
    }
}

/// Compares every deployed file against the record.
///
/// The comparison that matters is *which* hash a file differs from (PLAN.md §7.0): differing from
/// what the installer put there means the operator edited it, while agreeing with the record on a
/// host whose bundle has moved on means the overlay upstream is newer. A file recorded as
/// `kept-operator-modified` is theirs by definition, so a further edit there is not a finding.
fn overlay_row(record: &InstallRecord, root: Result<&ServUoRoot, &anyhow::Error>) -> Row {
    let Some(overlay) = &record.overlay else {
        return Row::fail("Overlay in sync", "no overlay recorded in install.json");
    };
    let Ok(root) = root else {
        return Row::fail(
            "Overlay in sync",
            format!("{} files recorded, tree unreadable", overlay.files.len()),
        );
    };

    let mut missing = Vec::new();
    let mut edited = Vec::new();
    let mut operator_owned = 0usize;

    for (rel, file) in &overlay.files {
        if file.state == "kept-operator-modified" {
            operator_owned += 1;
            continue;
        }
        let path = patch::join(&root.path, rel);
        match crate::util::sha256_file(&path) {
            Ok(actual) if actual == file.on_disk_sha256 => {}
            Ok(_) => edited.push(rel.clone()),
            Err(_) => missing.push(rel.clone()),
        }
    }

    let total = overlay.files.len();
    let owned = if operator_owned > 0 {
        format!(", {operator_owned} operator-owned")
    } else {
        String::new()
    };

    if missing.is_empty() && edited.is_empty() {
        return Row::ok(
            "Overlay in sync",
            format!("{total} files, all hashes match install.json{owned}"),
        );
    }

    let mark = if missing.is_empty() {
        Mark::Warn
    } else {
        Mark::Fail
    };
    let mut row = Row::new(
        mark,
        "Overlay in sync",
        format!(
            "{total} files{owned} — {} missing, {} edited since deployment",
            missing.len(),
            edited.len()
        ),
    )
    .notes_from(missing.iter().map(|f| format!("missing:  {f}")))
    .notes_from(edited.iter().map(|f| format!("edited:   {f}")));

    if !missing.is_empty() {
        row = row.note("run `update` (or `install`) to put the release's copies back");
    }
    if !edited.is_empty() {
        row = row.note(
            "these are code files the overlay owns — an `update` overwrites them without asking",
        );
    }
    row
}

/// Reports the patch tier from the record, then checks the tree still agrees with it.
///
/// The check is not decoration. The tier's whole risk is that its edits sit inside files ServUO
/// itself ships, so a core upgrade, a hand revert, or a restored backup silently removes them —
/// and nothing else in this report would notice. The cached `.patch` (PLAN.md §2.2) is what makes
/// the check possible offline: resolving it against the current file must land on rung 0, because
/// the record says it is already applied.
fn patch_row(
    record: &InstallRecord,
    root: Result<&ServUoRoot, &anyhow::Error>,
    layout: &paths::Layout,
) -> Row {
    let records = record.patch_records();
    if records.is_empty() {
        return Row::warn("Patch tier", "not applied — this is optional").note(
            "the two optional features (vendor.sale events, in-game moderation audit) are \
             unavailable; INSTALL.md §4",
        );
    }

    let applied: Vec<String> = records
        .iter()
        .map(|f| {
            let rungs: Vec<&str> = f.patches.iter().map(|p| p.rung.as_str()).collect();
            format!("{} ({})", f.feature, rungs.join(", "))
        })
        .collect();

    let unsupported: Vec<&str> = records
        .iter()
        .filter(|f| f.unsupported_servuo)
        .map(|f| f.feature.as_str())
        .collect();

    let mut notes = Vec::new();
    let mut gone = 0usize;

    match root {
        Ok(root) => {
            for feature in &records {
                for applied_patch in &feature.patches {
                    match verify_applied(layout, &applied_patch.name, &applied_patch.sha256) {
                        None => notes.push(format!(
                            "{}: no cached copy of the patch, so it could not be re-checked",
                            applied_patch.name
                        )),
                        Some(parsed) => {
                            let target = patch::join(&root.path, &applied_patch.target);
                            let content = std::fs::read(&target).unwrap_or_default();
                            let resolution = patch::resolve(&parsed, &content);
                            if !matches!(resolution, patch::Resolution::AlreadyPresent { .. }) {
                                gone += 1;
                                notes.push(format!(
                                    "{} is NO LONGER in {} — the file was replaced, reverted or \
                                     upgraded since it was applied",
                                    applied_patch.name, applied_patch.target
                                ));
                            }
                        }
                    }
                }
                for companion in &feature.companions {
                    if !patch::join(&root.path, &companion.path).is_file() {
                        gone += 1;
                        notes.push(format!("{} is missing from the tree", companion.path));
                    }
                }
            }
        }
        Err(_) => {
            notes.push("the ServUO tree is unreadable, so nothing could be re-checked".into())
        }
    }

    if !unsupported.is_empty() {
        // The label follows the install (PLAN.md §2.2.2): whoever inherits this shard must be able
        // to see it here, not only in the output of a run they never saw.
        notes.push(format!(
            "applied on an UNSUPPORTED ServUO ({}): {}",
            records
                .iter()
                .find_map(|f| f.servuo_version.clone())
                .unwrap_or_else(|| "unknown".into()),
            unsupported.join(", ")
        ));
    }

    let detail = format!("{} applied — {}", records.len(), applied.join("; "));
    let mark = if gone > 0 {
        Mark::Fail
    } else if unsupported.is_empty() {
        Mark::Ok
    } else {
        Mark::Warn
    };
    Row::new(mark, "Patch tier", detail).notes_from(notes)
}

/// Finds the cached `.patch` for a recorded patch and parses it.
///
/// By name first, which is what the tier writes; then by content hash across the cache, so a
/// release that renames a patch file does not silently turn this check off.
fn verify_applied(
    layout: &paths::Layout,
    name: &str,
    sha256: &str,
) -> Option<crate::diff::FilePatch> {
    let by_name = layout.patches_dir().join(format!("{name}.patch"));
    let candidates: Vec<PathBuf> = if by_name.is_file() {
        vec![by_name]
    } else {
        std::fs::read_dir(layout.patches_dir())
            .ok()?
            .filter_map(|e| e.ok())
            .map(|e| e.path())
            .filter(|p| p.extension().is_some_and(|e| e == "patch"))
            .collect()
    };

    for path in candidates {
        let Ok(bytes) = std::fs::read(&path) else {
            continue;
        };
        if path.file_stem().is_some_and(|s| s == name)
            || crate::util::sha256_bytes(&bytes) == sha256
        {
            if let Ok(parsed) = crate::diff::parse(&bytes) {
                return parsed.single_file().ok().cloned();
            }
        }
    }
    None
}

fn link_row(link: Option<&LinkRecord>, live: Option<&sidecar::ConfigDoc>) -> Row {
    let Some(link) = link else {
        return Row::fail("uo-link installed", "no sidecar recorded in install.json")
            .note("the overlay alone does not reach a website — see INSTALL.md §2");
    };
    let binary = Path::new(&link.binary.path);
    if !binary.is_file() {
        return Row::fail(
            "uo-link installed",
            format!("{} is missing", link.binary.path),
        );
    }

    // The version line comes from the binary, the hash decides whether it is the one that was
    // installed. A hand-replaced binary that still reports the right version is exactly the case a
    // version string alone would call healthy.
    let reported =
        sidecar::version_line(binary).unwrap_or_else(|| format!("uo-link {}", link.version));
    let row = match crate::util::sha256_file(binary) {
        Ok(actual) if actual.eq_ignore_ascii_case(&link.binary.sha256) => {
            Row::ok("uo-link installed", reported)
        }
        Ok(_) => Row::warn("uo-link installed", reported).note(format!(
            "{} is not the binary this installer recorded — it was replaced by hand or by another \
             tool",
            link.binary.path
        )),
        Err(error) => Row::warn("uo-link installed", reported)
            .note(format!("cannot hash {}: {error}", link.binary.path)),
    };

    // The paths the *binary* resolves, under the same environment the service definition pins (see
    // `live_config`) — not the ones the record believes it was told. A sidecar reading a different
    // config from the one the installer wrote is a failure mode nothing else here would surface.
    match live {
        Some(doc) => row.note(format!(
            "config {}   database {}",
            doc.config_path, doc.store.path
        )),
        None => row.note(format!(
            "config {} (not readable by this run)   database {}",
            link.config_path, link.db_path
        )),
    }
}

fn service_row(link: Option<&LinkRecord>) -> Row {
    let Some(link) = link else {
        return Row::fail("Service", "nothing recorded");
    };
    let Some(service) = &link.service else {
        // A deliberate outcome, not a bug: a host with no service manager the installer can drive
        // gets the binary, the config, and printed instructions (PLAN.md Phase 2).
        return Row::warn("Service", "not registered")
            .note("the binary and config are installed but nothing runs them — INSTALL.md §7");
    };

    let status = crate::service::observe(&service.kind, &service.name);
    let account = service
        .user
        .as_deref()
        .map(|u| format!("  as {u}"))
        .unwrap_or_default();
    let detail = format!("{}   {}{account}", service.name, status.detail);

    if !status.present {
        Row::fail("Service", detail).note("re-run `install` to register it again")
    } else if !status.running {
        Row::fail("Service", detail)
            .note("a service that will not stay up usually cannot read its config — INSTALL.md §7")
    } else if !status.enabled {
        Row::warn("Service", detail).note("it is running but will not come back after a reboot")
    } else {
        Row::ok("Service", detail)
    }
}

/// Asks the installed binary what it resolves — but only if it has a config to read.
///
/// Two rules are load-bearing here:
///
/// - **Only when the config already exists.** `--print-config` provisions: it writes the file and
///   mints a token when there is none. `doctor` must not write, and a diagnosis that created the
///   very state it was asked to report on would be worse than one that said "no config".
/// - **Under the environment the service runs with.** The systemd unit pins `UOLINK_DB_PATH`
///   wherever the database does not land beside the config (`crate::paths`), so a bare
///   `--print-config` would report the path the binary picks *on its own* — `/etc/runicgateway/`
///   rather than `/var/lib/runicgateway/` — and INSTALL.md §7 promises this row names the file the
///   service actually opens.
///
/// The returned document holds the auth token. Nothing here reads it, and nothing prints it.
fn live_config(link: &LinkRecord) -> Option<sidecar::ConfigDoc> {
    let config = Path::new(&link.config_path);
    if !config.is_file() {
        return None;
    }
    let db = Path::new(&link.db_path);
    let db_env = (config.parent() != db.parent()).then_some(db);
    sidecar::print_config(Path::new(&link.binary.path), config, db_env).ok()
}

/// The sidecar's `/health`, which needs no auth and is therefore safe to ask for from here.
///
/// Always over loopback, never over the configured bind: `[web] bind` is regularly `0.0.0.0`, and
/// this check is about whether the process on *this* host is answering.
fn health_of(bind: &str) -> Option<Health> {
    let port = bind.rsplit_once(':').map(|(_, p)| p).unwrap_or(bind);
    let url = format!("http://127.0.0.1:{port}/health");
    let body = net::get_text_within(&url, HEALTH_TIMEOUT).ok()?;
    serde_json::from_str(&body).ok()
}

/// The sidecar's `/health` document. Every field is optional so a newer sidecar that drops or
/// renames one still produces a report rather than a parse failure.
#[derive(Debug, Clone, Deserialize)]
pub struct Health {
    pub status: Option<String>,
    pub protocol: Option<u32>,
    pub plugin_connected: Option<bool>,
    pub database: Option<String>,
    pub uptime: Option<String>,
    pub last_event: Option<String>,
}

fn reachable_row(live: Option<&sidecar::ConfigDoc>, health: Option<&Health>) -> Row {
    let Some(doc) = live else {
        return Row::fail("Sidecar reachable", "could not read the sidecar's config").note(
            "either the config file is gone or this process cannot read it — it is deliberately \
             readable only by root/Administrator and the service account",
        );
    };
    let port = doc
        .web
        .bind
        .rsplit_once(':')
        .map(|(_, p)| p.to_string())
        .unwrap_or_else(|| doc.web.bind.clone());

    match health {
        Some(health) => {
            let uptime = health
                .uptime
                .as_deref()
                .map(|u| format!(", up {u}"))
                .unwrap_or_default();
            let db = health.database.as_deref().unwrap_or("unknown");
            Row::ok(
                "Sidecar reachable",
                format!(
                    "127.0.0.1:{port}  /health {}{uptime}, database {db}",
                    health.status.as_deref().unwrap_or("ok")
                ),
            )
        }
        None => Row::fail(
            "Sidecar reachable",
            format!("nothing answered http://127.0.0.1:{port}/health"),
        )
        .note("the binary is installed; this is about whether it is running and listening"),
    }
}

fn protocol_row(
    record: &InstallRecord,
    live: Option<&sidecar::ConfigDoc>,
    health: Option<&Health>,
) -> Row {
    let overlay = record.overlay.as_ref().map(|o| o.protocol);
    // `/health` first: that is the number the website is answered with. `--print-config` is the
    // same value from the same binary and covers a sidecar that is installed but not running.
    let sidecar = health.and_then(|h| h.protocol).or(live.map(|d| d.protocol));

    match (sidecar, overlay) {
        (Some(s), Some(o)) if s == o => {
            Row::ok("Protocol", format!("sidecar {s} = overlay manifest {o}"))
        }
        (Some(s), Some(o)) => Row::fail("Protocol", format!("sidecar {s} ≠ overlay manifest {o}"))
            .note(
                "the sidecar rejects a mismatched website with 409 rather than mis-parsing it; \
                 this pair was never checked together — run `update` to move both to one bundle",
            ),
        (s, o) => Row::warn(
            "Protocol",
            format!(
                "sidecar {}, overlay manifest {}",
                s.map(|v| v.to_string()).unwrap_or_else(|| "unknown".into()),
                o.map(|v| v.to_string()).unwrap_or_else(|| "unknown".into())
            ),
        ),
    }
}

/// The row the rest of the report exists to make trustworthy.
///
/// A shard that is not running cannot have dialed in, so that case is a `⚠` with the reason rather
/// than a `✗`: reporting a stopped shard as a failure would train operators to ignore this line,
/// which is the one line worth reading.
fn shard_row(root: Result<&ServUoRoot, &anyhow::Error>, health: Option<&Health>) -> Row {
    let running = root.ok().and_then(|r| servuo::find_running(&r.path));

    match (health.and_then(|h| h.plugin_connected), running) {
        (Some(true), _) => {
            let last = health
                .and_then(|h| h.last_event.clone())
                .map(|e| format!(" (last event {e})"))
                .unwrap_or_default();
            Row::ok("Shard connected", format!("yes{last}"))
        }
        (Some(false), Some(shard)) => Row::fail(
            "Shard connected",
            format!(
                "no — the shard is running (pid {}) but has not dialed in",
                shard.pid
            ),
        )
        .note(
            "the classic silent failure: ServUO ignores the script build's exit code and reloads \
             the previous Scripts.dll",
        )
        .note("run `[bridge status` in game, and check [shard] bind against Config/Bridge.cfg"),
        (Some(false), None) => Row::warn(
            "Shard connected",
            "no — the shard process is not running on this host",
        )
        .note("start ServUO and re-run doctor; nothing reaches the website until it dials in"),
        (None, _) => Row::warn(
            "Shard connected",
            "unknown — the sidecar did not answer /health",
        ),
    }
}

/// Whether this deployment is still the current bundle.
///
/// Offline is a `⚠`, never a `✗`. A shard host with no outbound route to Gitea is a supported way
/// to run this — the operator downloads artifacts elsewhere — and failing a health check over it
/// would report a working deployment as broken.
/// The most recent backup, so "can I go back?" is answerable without knowing the layout.
///
/// Always `✓`, never a failure: having no backup is the correct state on a host that has never
/// overwritten anything, and a shard that is running fine does not become broken because nothing
/// has displaced a file yet.
fn backup_row(layout: &paths::Layout) -> Row {
    let backups = crate::backup::list(layout);
    let Some(newest) = backups.first() else {
        return Row::ok("Backups", "none taken — no run has replaced a file yet");
    };
    let detail = match crate::backup::read_manifest(newest) {
        Ok(manifest) => format!(
            "{} — {} file(s) replaced by {} to bundle {}",
            manifest.taken,
            manifest.files.len(),
            manifest.command,
            manifest.bundle_to
        ),
        // A directory with an unreadable manifest is still a directory of the operator's files, so
        // it is reported rather than skipped.
        Err(_) => format!("{} — manifest unreadable", newest.display()),
    };
    Row::ok("Backups", detail).note(format!(
        "{} kept in {}",
        backups.len(),
        layout.backups_dir().display()
    ))
}

fn bundle_row(record: &InstallRecord) -> Row {
    let url = bundle::url_for(None);
    let current = match net::get_text_within(&url, BUNDLE_TIMEOUT).and_then(|b| bundle::parse(&b)) {
        Ok(bundle) => bundle,
        Err(error) => {
            return Row::warn(
                "Bundle",
                format!("{} — could not check for a newer one", record.bundle.tag),
            )
            .note(error.to_string().replace('\n', " "))
        }
    };

    if current.bundle == record.bundle.tag {
        return Row::ok("Bundle", format!("{} — up to date", record.bundle.tag));
    }

    let mut moves = Vec::new();
    if let Some(link) = record.link_record() {
        if link.version != current.link.version {
            moves.push(format!(
                "uo-link {} → {}",
                link.version, current.link.version
            ));
        }
    }
    if let Some(overlay) = &record.overlay {
        if overlay.version != current.overlay.version {
            moves.push(format!(
                "overlay {} → {}",
                overlay.version, current.overlay.version
            ));
        }
    }
    let detail = if moves.is_empty() {
        format!(
            "{} → {} (no component changed)",
            record.bundle.tag, current.bundle
        )
    } else {
        format!(
            "{} → {}: {}",
            record.bundle.tag,
            current.bundle,
            moves.join(", ")
        )
    };
    Row::warn("Bundle", detail).note("run `update` to move both halves to one checked combination")
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::record::{BundleRef, FileRecord, InstallerInfo, OverlayRecord, ServUoRef, SCHEMA};
    use std::collections::BTreeMap;

    fn record() -> InstallRecord {
        InstallRecord {
            schema: SCHEMA,
            installer: InstallerInfo {
                version: "0.1.0".into(),
            },
            updated: "2026-08-05T10:00:00Z".into(),
            bundle: BundleRef {
                tag: "2026.08.04".into(),
                protocol: 3,
                url: "https://example/current.json".into(),
            },
            servuo: ServUoRef {
                path: "/opt/ServUO".into(),
                version: Some("57.4".into()),
            },
            overlay: Some(OverlayRecord {
                repo: "RunicGateway/servuo-plugins".into(),
                tag: "v0.1.1".into(),
                version: "0.1.1".into(),
                commit: "3a52abb".into(),
                protocol: 3,
                files: BTreeMap::new(),
            }),
            link: None,
            patches: Vec::new(),
            extra: BTreeMap::new(),
        }
    }

    fn health(protocol: u32, connected: bool) -> Health {
        Health {
            status: Some("ok".into()),
            protocol: Some(protocol),
            plugin_connected: Some(connected),
            database: Some("ok".into()),
            uptime: Some("2m".into()),
            last_event: Some("2026-08-05T10:00:00Z".into()),
        }
    }

    #[test]
    fn the_documented_health_document_parses() {
        // Copied from INSTALL.md §6 — the shape doctor's last three rows are read from.
        let body = r#"{"status":"ok","protocol":3,"plugin_connected":true,"database":"ok",
                       "uptime":"2m","last_event":"2026-08-04T18:22:10.412Z"}"#;
        let health: Health = serde_json::from_str(body).unwrap();
        assert_eq!(health.protocol, Some(3));
        assert_eq!(health.plugin_connected, Some(true));
    }

    #[test]
    fn a_health_document_missing_fields_still_parses() {
        // A newer sidecar dropping or renaming a key must degrade to an unknown row, not to a
        // doctor that cannot report at all.
        let health: Health = serde_json::from_str(r#"{"status":"ok"}"#).unwrap();
        assert_eq!(health.protocol, None);
        assert_eq!(health.plugin_connected, None);
    }

    #[test]
    fn a_protocol_mismatch_fails_the_row() {
        assert_eq!(
            protocol_row(&record(), None, Some(&health(3, true))).mark,
            Mark::Ok
        );
        assert_eq!(
            protocol_row(&record(), None, Some(&health(4, true))).mark,
            Mark::Fail
        );
        // Nothing to compare is not a failure — an unreachable sidecar is already its own ✗ row,
        // and reporting the same outage twice buries the one that names the cause.
        assert_eq!(protocol_row(&record(), None, None).mark, Mark::Warn);
    }

    #[test]
    fn a_stopped_shard_is_a_warning_and_a_silent_one_is_a_failure() {
        // The distinction the whole row exists for: "you have not started it" and "it is running
        // and the bridge is dead" are different problems, and only the second is broken.
        let err = anyhow::anyhow!("no tree");
        assert_eq!(
            shard_row(Err(&err), Some(&health(3, false))).mark,
            Mark::Warn
        );
        assert_eq!(shard_row(Err(&err), Some(&health(3, true))).mark, Mark::Ok);
        assert_eq!(shard_row(Err(&err), None).mark, Mark::Warn);
    }

    #[test]
    fn an_empty_patch_tier_is_a_warning_not_a_failure() {
        // The tier is optional and most shards will decline it. A ✗ there would make a correct
        // install look broken forever.
        let layout = paths::layout();
        let err = anyhow::anyhow!("no tree");
        assert_eq!(patch_row(&record(), Err(&err), &layout).mark, Mark::Warn);
    }

    #[test]
    fn a_missing_overlay_file_fails_and_an_edited_one_warns() {
        let dir = crate::util::TempDir::new("rg-test-doctor").unwrap();
        let root = ServUoRoot {
            path: dir.path().to_path_buf(),
            version: Some("57.4".into()),
        };
        std::fs::create_dir_all(dir.path().join("Scripts")).unwrap();
        std::fs::write(dir.path().join("Scripts/A.cs"), b"deployed").unwrap();
        let deployed = crate::util::sha256_bytes(b"deployed");

        let mut record = record();
        let files = &mut record.overlay.as_mut().unwrap().files;
        files.insert(
            "Scripts/A.cs".into(),
            FileRecord {
                overlay_sha256: deployed.clone(),
                on_disk_sha256: deployed.clone(),
                state: "deployed".into(),
            },
        );
        assert_eq!(overlay_row(&record, Ok(&root)).mark, Mark::Ok);

        std::fs::write(dir.path().join("Scripts/A.cs"), b"edited by hand").unwrap();
        assert_eq!(overlay_row(&record, Ok(&root)).mark, Mark::Warn);

        std::fs::remove_file(dir.path().join("Scripts/A.cs")).unwrap();
        assert_eq!(overlay_row(&record, Ok(&root)).mark, Mark::Fail);
    }

    #[test]
    fn an_operator_owned_file_is_never_reported_as_drift() {
        // Bridge.cfg is *meant* to be edited in place; flagging it every run would teach operators
        // to ignore this row.
        let dir = crate::util::TempDir::new("rg-test-doctor-owned").unwrap();
        let root = ServUoRoot {
            path: dir.path().to_path_buf(),
            version: Some("57.4".into()),
        };
        std::fs::create_dir_all(dir.path().join("Config")).unwrap();
        std::fs::write(dir.path().join("Config/Bridge.cfg"), b"edited again").unwrap();

        let mut record = record();
        record.overlay.as_mut().unwrap().files.insert(
            "Config/Bridge.cfg".into(),
            FileRecord {
                overlay_sha256: "aa".into(),
                on_disk_sha256: "bb".into(),
                state: "kept-operator-modified".into(),
            },
        );
        let row = overlay_row(&record, Ok(&root));
        assert_eq!(row.mark, Mark::Ok);
        assert!(row.detail.contains("operator-owned"), "{}", row.detail);
    }
}