exec.zig

1// exec.zig — all process execution and SSH routing2// Commands call these functions; output is streamed or captured here.3const std = @import("std");4const builtin = @import("builtin");5const types = @import("types.zig");6const errors = @import("errors.zig");7const output = @import("output.zig");89// nixos-rebuild manages this profile; generation commands must target it10// explicitly. Bare nix-env defaults to the per-user profile, which is empty.11const SYSTEM_PROFILE = "/nix/var/nix/profiles/system";1213pub const RunResult = struct {14    stdout: []u8,15    stderr: []u8,16    exit_code: u8,17};1819// Run a process and capture stdout+stderr (not streaming).20pub fn capture(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine, cmd: []const []const u8) !RunResult {21    const argv = try buildArgv(gpa, machine, cmd);22    defer if (!machine.local) gpa.free(argv);2324    const result = std.process.run(gpa, io, .{ .argv = argv }) catch |e| {25        errors.error_info.setMessage("process failed: {s}", .{cmd[0]});26        return e;27    };2829    return .{30        .stdout = result.stdout,31        .stderr = result.stderr,32        .exit_code = switch (result.term) {33            .exited => |c| c,34            else => 1,35        },36    };37}3839// Run a process and stream its output to the terminal (inherit stdio).40pub fn stream(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, cmd: []const []const u8) !u8 {41    // The child inherits stdout and writes directly to the fd; flush any buffered42    // nina header first so it isn't reordered after the child's output.43    output.flush();44    const argv = try buildArgv(gpa, machine, cmd);45    defer if (!machine.local) gpa.free(argv);4647    var child = std.process.spawn(io, .{48        .argv = argv,49        .stdin = .inherit,50        .stdout = .inherit,51        .stderr = .inherit,52    }) catch |e| {53        errors.error_info.setMessage("failed to spawn: {s}", .{cmd[0]});54        return e;55    };5657    const term = child.wait(io) catch |e| {58        errors.error_info.setMessage("process wait failed", .{});59        return e;60    };6162    return switch (term) {63        .exited => |c| c,64        else => 1,65    };66}6768// Stream a local process with inherited stdio (no SSH routing — for nix commands).69pub fn streamLocal(io: std.Io, cmd: []const []const u8) !u8 {70    output.flush();71    var child = std.process.spawn(io, .{72        .argv = cmd,73        .stdin = .inherit,74        .stdout = .inherit,75        .stderr = .inherit,76    }) catch |e| {77        errors.error_info.setMessage("failed to spawn: {s}", .{cmd[0]});78        return e;79    };80    const term = child.wait(io) catch {81        errors.error_info.setMessage("process wait failed", .{});82        return error.ProcessFailed;83    };84    return switch (term) {85        .exited => |c| c,86        else => 1,87    };88}8990// Run a process and capture output as a single string (no SSH routing — for local nix commands).91pub fn captureLocal(gpa: std.mem.Allocator, io: std.Io, cmd: []const []const u8) ![]u8 {92    const result = std.process.run(gpa, io, .{ .argv = cmd }) catch return error.ProcessFailed;93    defer gpa.free(result.stderr);94    switch (result.term) {95        .exited => |c| if (c != 0) {96            gpa.free(result.stdout);97            return error.ProcessFailed;98        },99        else => {100            gpa.free(result.stdout);101            return error.ProcessFailed;102        },103    }104    return result.stdout;105}106107fn buildArgv(gpa: std.mem.Allocator, machine: *const types.Machine, cmd: []const []const u8) ![]const []const u8 {108    if (machine.local) return cmd;109110    const host = machine.host orelse {111        errors.error_info.setMessage("machine '{s}' has no host configured", .{machine.name});112        return error.SshFailed;113    };114115    var ssh: std.ArrayList([]const u8) = .empty;116    try ssh.append(gpa, "ssh");117    try ssh.append(gpa, "-o");118    try ssh.append(gpa, "BatchMode=yes");119    try ssh.append(gpa, "-o");120    try ssh.append(gpa, "StrictHostKeyChecking=accept-new");121    if (machine.ssh_key) |key| {122        try ssh.append(gpa, "-i");123        try ssh.append(gpa, key);124    }125    const addr = if (machine.user) |u|126        try std.fmt.allocPrint(gpa, "{s}@{s}", .{ u, host })127    else128        try gpa.dupe(u8, host);129    try ssh.append(gpa, addr);130    for (cmd) |arg| try ssh.append(gpa, arg);131    return ssh.toOwnedSlice(gpa);132}133134// --- NixOS rebuild ---135136pub fn nixosRebuildSwitch(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {137    const cmd = &.{ "sudo", "nixos-rebuild", "switch" };138    output.printSubstep("nixos-rebuild switch", .{});139    return stream(io, machine, gpa, cmd);140}141142pub fn nixosRebuildDryActivate(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {143    return stream(io, machine, gpa, &.{ "sudo", "nixos-rebuild", "dry-activate" });144}145146pub fn nixosRebuildBuild(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {147    return stream(io, machine, gpa, &.{ "sudo", "nixos-rebuild", "build" });148}149150// --- Generations ---151152// Read system-profile generations WITHOUT root. `nix-env --list-generations -p153// /nix/var/nix/profiles/system` takes a profile lock and fails as a normal user154// ("system.lock: Permission denied"). The generation symlinks themselves are155// world-readable, so list them directly: parse `system-N-link` names, take each156// link's own mtime for the date/time, and mark the one the `system` symlink157// points at as current. Output matches the `nix-env --list-generations` columns158// (num date time [current]) so parseGenerations is unchanged.159const GEN_LIST_SCRIPT =160    \\cur=$(readlink /nix/var/nix/profiles/system 2>/dev/null | sed 's/.*system-\([0-9]*\)-link/\1/'); find /nix/var/nix/profiles -maxdepth 1 -name 'system-*-link' -printf '%f %TY-%Tm-%Td %TH:%TM\n' 2>/dev/null | sed 's/system-\([0-9]*\)-link/\1/' | sort -n | awk -v c="$cur" '{ if ($1==c) print $0" current"; else print $0 }'161;162163pub fn getGenerations(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) ![]types.GenerationInfo {164    const r = try capture(gpa, io, machine, &.{ "sh", "-c", GEN_LIST_SCRIPT });165    defer gpa.free(r.stderr);166    defer gpa.free(r.stdout);167    if (r.exit_code != 0) return error.ProcessFailed;168    return parseGenerations(gpa, r.stdout);169}170171fn parseGenerations(gpa: std.mem.Allocator, output_str: []const u8) ![]types.GenerationInfo {172    var gens: std.ArrayList(types.GenerationInfo) = .empty;173    var lines = std.mem.splitScalar(u8, output_str, '\n');174    while (lines.next()) |line| {175        const trimmed = std.mem.trim(u8, line, " \t");176        if (trimmed.len == 0) continue;177        var parts = std.mem.tokenizeAny(u8, trimmed, " \t");178        const num_str = parts.next() orelse continue;179        const date_str = parts.next() orelse continue;180        const time_str = parts.next() orelse continue;181        const rest = parts.rest();182        const current = std.mem.indexOf(u8, rest, "current") != null;183        const num = std.fmt.parseInt(u32, num_str, 10) catch continue;184        try gens.append(gpa, .{185            .number = num,186            .date = try gpa.dupe(u8, date_str),187            .time = try gpa.dupe(u8, time_str),188            .current = current,189        });190    }191    return gens.toOwnedSlice(gpa);192}193194pub fn getCurrentGeneration(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) !u32 {195    const gens = try getGenerations(gpa, io, machine);196    defer gpa.free(gens);197    for (gens) |g| {198        if (g.current) return g.number;199    }200    return 0;201}202203pub fn switchGeneration(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, n: u32) !u8 {204    // Switch the system profile to generation n, then activate it (bootloader +205    // services). Without switch-to-configuration the change isn't applied.206    const cmd = try std.fmt.allocPrint(gpa, "nix-env -p {s} --switch-generation {d} && {s}/bin/switch-to-configuration switch", .{ SYSTEM_PROFILE, n, SYSTEM_PROFILE });207    defer gpa.free(cmd);208    return stream(io, machine, gpa, &.{ "sudo", "sh", "-c", cmd });209}210211pub fn rollback(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {212    return stream(io, machine, gpa, &.{ "sudo", "nixos-rebuild", "switch", "--rollback" });213}214215pub fn deleteGeneration(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, n: u32) !u8 {216    const n_str = try std.fmt.allocPrint(gpa, "{d}", .{n});217    defer gpa.free(n_str);218    return stream(io, machine, gpa, &.{ "sudo", "nix-env", "-p", SYSTEM_PROFILE, "--delete-generations", n_str });219}220221pub fn deleteOldGenerations(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {222    return stream(io, machine, gpa, &.{ "sudo", "nix-env", "-p", SYSTEM_PROFILE, "--delete-generations", "old" });223}224225// --- Garbage collection ---226227pub fn collectGarbage(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, delete_old: bool, keep: u32) !u8 {228    if (delete_old) {229        return stream(io, machine, gpa, &.{ "sudo", "nix-collect-garbage", "-d" });230    }231    // Keep the `keep` most recent system generations (+N deletes all but N),232    // then collect now-unreferenced store paths. `--delete-older-than` wants a233    // duration (e.g. 14d), not a generation count.234    const cmd = try std.fmt.allocPrint(gpa, "nix-env -p {s} --delete-generations +{d} && nix-collect-garbage", .{ SYSTEM_PROFILE, keep });235    defer gpa.free(cmd);236    return stream(io, machine, gpa, &.{ "sudo", "sh", "-c", cmd });237}238239// --- Channels ---240241pub fn channelList(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) ![]types.ChannelInfo {242    const r = try capture(gpa, io, machine, &.{ "nix-channel", "--list" });243    defer gpa.free(r.stderr);244    defer gpa.free(r.stdout);245    if (r.exit_code != 0) return error.ProcessFailed;246    return parseChannels(gpa, r.stdout);247}248249fn parseChannels(gpa: std.mem.Allocator, output_str: []const u8) ![]types.ChannelInfo {250    var channels: std.ArrayList(types.ChannelInfo) = .empty;251    var lines = std.mem.splitScalar(u8, output_str, '\n');252    while (lines.next()) |line| {253        const trimmed = std.mem.trim(u8, line, " \t\r");254        if (trimmed.len == 0) continue;255        const space = std.mem.indexOfScalar(u8, trimmed, ' ') orelse continue;256        try channels.append(gpa, .{257            .name = try gpa.dupe(u8, trimmed[0..space]),258            .url = try gpa.dupe(u8, std.mem.trim(u8, trimmed[space + 1 ..], " \t")),259        });260    }261    return channels.toOwnedSlice(gpa);262}263264pub fn channelUpdate(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {265    return stream(io, machine, gpa, &.{ "sudo", "nix-channel", "--update" });266}267268pub fn channelAdd(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, url: []const u8, name: []const u8) !u8 {269    return stream(io, machine, gpa, &.{ "sudo", "nix-channel", "--add", url, name });270}271272pub fn channelRemove(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, name: []const u8) !u8 {273    return stream(io, machine, gpa, &.{ "sudo", "nix-channel", "--remove", name });274}275276// --- Services ---277278pub fn serviceList(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) ![]types.ServiceInfo {279    const r = try capture(gpa, io, machine, &.{ "systemctl", "list-units", "--type=service", "--no-legend", "--no-pager" });280    defer gpa.free(r.stderr);281    defer gpa.free(r.stdout);282    if (r.exit_code != 0) return error.ProcessFailed;283    return parseServices(gpa, r.stdout);284}285286fn parseServices(gpa: std.mem.Allocator, output_str: []const u8) ![]types.ServiceInfo {287    var svcs: std.ArrayList(types.ServiceInfo) = .empty;288    var lines = std.mem.splitScalar(u8, output_str, '\n');289    while (lines.next()) |line| {290        const trimmed = std.mem.trim(u8, line, " \t\r");291        if (trimmed.len == 0 or trimmed[0] == 0xE2) continue; // skip UTF-8 bullet lines292        var parts = std.mem.tokenizeAny(u8, trimmed, " \t");293        const name = parts.next() orelse continue;294        _ = parts.next(); // load295        const active_str = parts.next() orelse continue;296        const sub_str = parts.next() orelse "unknown";297298        const state: types.ServiceState = if (std.mem.eql(u8, active_str, "active"))299            (if (std.mem.eql(u8, sub_str, "running") or std.mem.eql(u8, sub_str, "exited")) .active else .active)300        else if (std.mem.eql(u8, active_str, "failed"))301            .failed302        else303            .inactive;304305        try svcs.append(gpa, .{306            .name = try gpa.dupe(u8, name),307            .state = state,308            .uptime = null,309        });310    }311    return svcs.toOwnedSlice(gpa);312}313314pub fn serviceCtl(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, verb: []const u8, name: []const u8) !u8 {315    // --no-pager: `systemctl status` pipes to a pager on a tty and would block.316    return stream(io, machine, gpa, &.{ "sudo", "systemctl", "--no-pager", verb, name });317}318319pub fn serviceLogs(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, name: []const u8, last: u32, follow: bool) !u8 {320    const n_str = try std.fmt.allocPrint(gpa, "{d}", .{last});321    defer gpa.free(n_str);322    if (follow) {323        return stream(io, machine, gpa, &.{ "journalctl", "-u", name, "-f" });324    }325    return stream(io, machine, gpa, &.{ "journalctl", "-u", name, "-n", n_str, "--no-pager" });326}327328// --- Profile ---329330pub fn profileInstall(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, attr: []const u8) !u8 {331    const pkg_ref = try std.fmt.allocPrint(gpa, "nixpkgs#{s}", .{attr});332    defer gpa.free(pkg_ref);333    return stream(io, machine, gpa, &.{ "nix", "profile", "install", pkg_ref });334}335336pub fn profileRemove(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, attr: []const u8) !u8 {337    // `nix profile remove` matches by profile element name (e.g. "ripgrep"), not338    // by flake ref — passing nixpkgs#ripgrep matches nothing.339    return stream(io, machine, gpa, &.{ "nix", "profile", "remove", attr });340}341342pub fn profileList(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) ![]u8 {343    const r = try capture(gpa, io, machine, &.{ "nix", "profile", "list" });344    defer gpa.free(r.stderr);345    if (r.exit_code != 0) return error.ProcessFailed;346    return r.stdout;347}348349pub fn profileUpgrade(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {350    return stream(io, machine, gpa, &.{ "nix", "profile", "upgrade", ".*" });351}352353// --- Store ---354355pub fn storeGc(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {356    return stream(io, machine, gpa, &.{ "sudo", "nix-collect-garbage" });357}358359pub fn storeVerify(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {360    return stream(io, machine, gpa, &.{ "nix", "store", "verify", "--all" });361}362363pub const SystemStatus = struct { size: []u8, age: []u8 };364365// One read-only pass for `nina status`: the current system's closure size (a366// single `path-info -S` of /run/current-system — fast, unlike -S over the whole367// store) and seconds since the system profile was last switched (its symlink368// mtime). Both are world-readable; no root needed.369const STATUS_SCRIPT =370    \\sz=$(nix path-info -S /run/current-system 2>/dev/null | awk '{print $NF}'); mt=$(stat -c %Y /nix/var/nix/profiles/system 2>/dev/null); now=$(date +%s); echo "${sz:-0} $(( ${now:-0} - ${mt:-0} ))"371;372373pub fn systemStatus(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) SystemStatus {374    const unknown = SystemStatus{375        .size = gpa.dupe(u8, "") catch return .{ .size = "", .age = "" },376        .age = gpa.dupe(u8, "") catch return .{ .size = "", .age = "" },377    };378    const r = capture(gpa, io, machine, &.{ "sh", "-c", STATUS_SCRIPT }) catch return unknown;379    defer gpa.free(r.stdout);380    defer gpa.free(r.stderr);381    if (r.exit_code != 0) return unknown;382383    var it = std.mem.tokenizeAny(u8, r.stdout, " \t\n\r");384    const sz_str = it.next() orelse return unknown;385    const age_str = it.next() orelse return unknown;386    const bytes = std.fmt.parseInt(u64, sz_str, 10) catch 0;387    const age_secs = std.fmt.parseInt(u64, age_str, 10) catch 0;388389    gpa.free(unknown.size);390    gpa.free(unknown.age);391    return .{392        .size = humanSize(gpa, bytes) catch (gpa.dupe(u8, "") catch ""),393        .age = humanAgo(gpa, age_secs) catch (gpa.dupe(u8, "") catch ""),394    };395}396397// `systemctl is-system-running` -> "running" / "degraded" / "starting" ... A398// one-word health signal; exits non-zero when degraded, so we read stdout, not399// the code. Caller owns the returned slice.400pub fn systemRunningState(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) ![]u8 {401    const r = capture(gpa, io, machine, &.{ "systemctl", "is-system-running" }) catch402        return gpa.dupe(u8, "unknown");403    defer gpa.free(r.stderr);404    const state = std.mem.trim(u8, r.stdout, " \t\n\r");405    const owned = try gpa.dupe(u8, if (state.len > 0) state else "unknown");406    gpa.free(r.stdout);407    return owned;408}409410fn humanAgo(gpa: std.mem.Allocator, secs: u64) ![]u8 {411    if (secs < 60) return std.fmt.allocPrint(gpa, "{d}s ago", .{secs});412    if (secs < 3600) return std.fmt.allocPrint(gpa, "{d}m ago", .{secs / 60});413    if (secs < 86400) return std.fmt.allocPrint(gpa, "{d}h ago", .{secs / 3600});414    return std.fmt.allocPrint(gpa, "{d}d ago", .{secs / 86400});415}416417pub fn storeRepair(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {418    return stream(io, machine, gpa, &.{ "sudo", "nix", "store", "repair", "--all" });419}420421pub fn storeInfo(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) !types.StoreInfo {422    // `nix path-info -S --all` computes the CLOSURE size of every path — O(paths^2)423    // graph work that takes minutes on a real store (59k+ paths) and hangs the424    // command. We don't need closures: `--all --json` (no -S) carries each path's425    // own narSize, so one fast pass gives the path count and the summed store size.426    // `du -sh /nix/store` is just as slow on a big store, so it's gone too.427    // timeout-wrapped so a pathological store degrades to "?" instead of hanging.428    const pi = try capture(gpa, io, machine, &.{ "sh", "-c", "timeout 90 nix path-info --all --json 2>/dev/null" });429    defer gpa.free(pi.stdout);430    defer gpa.free(pi.stderr);431432    const scan = scanStoreJson(pi.stdout);433    const total_owned = try humanSize(gpa, scan.total_bytes);434435    return .{436        .total_size = total_owned,437        .live_paths = scan.count,438        .reclaimable_paths = 0,439    };440}441442const StoreScan = struct { count: u64, total_bytes: u64 };443444// One linear pass over `nix path-info --json`: each path object has exactly one445// "narSize": field, so counting them gives the true path count and summing the446// values gives the total store size — no per-path closure walk.447fn scanStoreJson(json_str: []const u8) StoreScan {448    const needle = "\"narSize\":";449    var count: u64 = 0;450    var total: u64 = 0;451    var i: usize = 0;452    while (std.mem.indexOfPos(u8, json_str, i, needle)) |pos| {453        var j = pos + needle.len;454        while (j < json_str.len and json_str[j] == ' ') : (j += 1) {}455        var val: u64 = 0;456        var any = false;457        while (j < json_str.len and json_str[j] >= '0' and json_str[j] <= '9') : (j += 1) {458            val = val * 10 + (json_str[j] - '0');459            any = true;460        }461        if (any) {462            count += 1;463            total += val;464        }465        i = j;466    }467    return .{ .count = count, .total_bytes = total };468}469470fn humanSize(gpa: std.mem.Allocator, bytes: u64) ![]u8 {471    const units = [_][]const u8{ "B", "KB", "MB", "GB", "TB" };472    var val: f64 = @floatFromInt(bytes);473    var unit: usize = 0;474    while (val >= 1024.0 and unit + 1 < units.len) : (unit += 1) val /= 1024.0;475    if (unit == 0) return std.fmt.allocPrint(gpa, "{d} {s}", .{ bytes, units[0] });476    return std.fmt.allocPrint(gpa, "{d:.1} {s}", .{ val, units[unit] });477}478479pub fn storePath(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine, attr: []const u8) ![]u8 {480    // nixpkgs#<attr>, not .#<attr>: the package lives in nixpkgs (resolved via the481    // flake registry), not a flake in the current directory.482    const expr = try std.fmt.allocPrint(gpa, "nixpkgs#{s}.outPath", .{attr});483    defer gpa.free(expr);484    const r = try capture(gpa, io, machine, &.{ "nix", "eval", "--raw", expr });485    defer gpa.free(r.stderr);486    if (r.exit_code != 0) {487        gpa.free(r.stdout);488        return error.ProcessFailed;489    }490    return r.stdout;491}492493// --- Flake ---494495pub fn flakeUpdate(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, input: ?[]const u8) !u8 {496    if (input) |inp| {497        return stream(io, machine, gpa, &.{ "nix", "flake", "update", inp });498    }499    return stream(io, machine, gpa, &.{ "nix", "flake", "update" });500}501502pub fn flakeCheck(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {503    return stream(io, machine, gpa, &.{ "nix", "flake", "check" });504}505506pub fn flakeInit(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {507    return stream(io, machine, gpa, &.{ "nix", "flake", "init" });508}509510pub fn flakeLock(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {511    return stream(io, machine, gpa, &.{ "nix", "flake", "lock" });512}513514pub fn flakeClone(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, url: []const u8) !u8 {515    return stream(io, machine, gpa, &.{ "nix", "flake", "clone", url });516}517518pub fn flakeShow(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) ![]u8 {519    const r = try capture(gpa, io, machine, &.{ "nix", "flake", "show", "--json" });520    defer gpa.free(r.stderr);521    if (r.exit_code != 0) {522        gpa.free(r.stdout);523        return error.ProcessFailed;524    }525    return r.stdout;526}527528// --- Build / Run / Develop ---529530pub fn nixBuild(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, attr: ?[]const u8) !u8 {531    if (attr) |a| {532        const ref = try std.fmt.allocPrint(gpa, ".#{s}", .{a});533        defer gpa.free(ref);534        return stream(io, machine, gpa, &.{ "nix", "build", ref });535    }536    return stream(io, machine, gpa, &.{ "nix", "build" });537}538539pub fn nixRun(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, pkg: []const u8) !u8 {540    // nix run always gets --no-write-lock-file for remote URLs541    const is_url = std.mem.startsWith(u8, pkg, "http://") or std.mem.startsWith(u8, pkg, "https://") or std.mem.startsWith(u8, pkg, "github:");542    if (is_url) {543        return stream(io, machine, gpa, &.{ "nix", "run", pkg, "--no-write-lock-file" });544    }545    // Already a flake ref (contains '#') → use as-is; bare name → default to nixpkgs#.546    if (std.mem.indexOfScalar(u8, pkg, '#') != null) {547        return stream(io, machine, gpa, &.{ "nix", "run", pkg });548    }549    const ref = try std.fmt.allocPrint(gpa, "nixpkgs#{s}", .{pkg});550    defer gpa.free(ref);551    return stream(io, machine, gpa, &.{ "nix", "run", ref });552}553554pub fn nixShell(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, pkg: []const u8) !u8 {555    const ref = try std.fmt.allocPrint(gpa, "nixpkgs#{s}", .{pkg});556    defer gpa.free(ref);557    return stream(io, machine, gpa, &.{ "nix", "shell", ref });558}559560pub fn nixDevelop(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, run_cmd: ?[]const u8) !u8 {561    if (run_cmd) |cmd| {562        // sh -c so a multi-word command isn't treated as a single executable name.563        return stream(io, machine, gpa, &.{ "nix", "develop", "--command", "sh", "-c", cmd });564    }565    return stream(io, machine, gpa, &.{ "nix", "develop" });566}567568pub fn nixRepl(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator) !u8 {569    return stream(io, machine, gpa, &.{ "nix", "repl", "--expr", "import <nixpkgs> {}" });570}571572// --- Format ---573574pub fn nixpkgsFmt(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, path: []const u8, check: bool) !u8 {575    if (check) {576        return stream(io, machine, gpa, &.{ "nixpkgs-fmt", "--check", path });577    }578    return stream(io, machine, gpa, &.{ "nixpkgs-fmt", path });579}580581// --- Info ---582583pub fn systemInfo(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) ![]u8 {584    const r = try capture(gpa, io, machine, &.{"nixos-version"});585    defer gpa.free(r.stderr);586    if (r.exit_code != 0) {587        gpa.free(r.stdout);588        return error.ProcessFailed;589    }590    return r.stdout;591}592593pub fn kernelInfo(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) ![]u8 {594    const r = try capture(gpa, io, machine, &.{ "uname", "-r" });595    defer gpa.free(r.stderr);596    if (r.exit_code != 0) {597        gpa.free(r.stdout);598        return error.ProcessFailed;599    }600    return r.stdout;601}602603pub fn uptimeInfo(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) ![]u8 {604    const r = try capture(gpa, io, machine, &.{"uptime"});605    defer gpa.free(r.stderr);606    if (r.exit_code != 0) {607        gpa.free(r.stdout);608        return error.ProcessFailed;609    }610    return r.stdout;611}612613// --- Boot ---614615pub fn bootEntries(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) ![]types.BootEntry {616    const r = try capture(gpa, io, machine, &.{ "bootctl", "list" });617    defer gpa.free(r.stderr);618    defer gpa.free(r.stdout);619    if (r.exit_code != 0) return error.ProcessFailed;620    return parseBootEntries(gpa, r.stdout);621}622623fn parseBootEntries(gpa: std.mem.Allocator, output_str: []const u8) ![]types.BootEntry {624    var entries: std.ArrayList(types.BootEntry) = .empty;625    var lines = std.mem.splitScalar(u8, output_str, '\n');626    while (lines.next()) |line| {627        const trimmed = std.mem.trim(u8, line, " \t\r");628        if (std.mem.startsWith(u8, trimmed, "title:")) {629            const title = std.mem.trim(u8, trimmed[6..], " \t");630            const current = std.mem.indexOf(u8, title, "(current)") != null;631            try entries.append(gpa, .{632                .title = try gpa.dupe(u8, title),633                .current = current,634            });635        }636    }637    return entries.toOwnedSlice(gpa);638}639640// --- Pkg info ---641642pub fn pkgWhy(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, pkg: []const u8) !u8 {643    return stream(io, machine, gpa, &.{ "nix", "why-depends", ".#", pkg });644}645646pub fn pkgDeps(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, pkg: []const u8) !u8 {647    return stream(io, machine, gpa, &.{ "nix-store", "--query", "--requisites", pkg });648}649650pub fn pkgSize(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine, pkg: []const u8) ![]u8 {651    // A bare name ("ripgrep") isn't a valid installable; resolve via nixpkgs# like652    // `pkg path` does. -S -h gives closure size, human-readable. Output is653    // "<store-path>   <size>"; return just the size.654    const ref = try std.fmt.allocPrint(gpa, "nixpkgs#{s}", .{pkg});655    defer gpa.free(ref);656    const r = try capture(gpa, io, machine, &.{ "nix", "path-info", "-S", "-h", ref });657    defer gpa.free(r.stderr);658    defer gpa.free(r.stdout);659    if (r.exit_code != 0) return error.ProcessFailed;660661    const line = std.mem.trim(u8, r.stdout, " \t\n\r");662    var it = std.mem.tokenizeAny(u8, line, " \t");663    _ = it.next(); // store path664    const size = std.mem.trim(u8, it.rest(), " \t");665    if (size.len == 0) return error.ProcessFailed;666    return gpa.dupe(u8, size);667}668669pub fn pkgClosure(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, pkg: []const u8) !u8 {670    return stream(io, machine, gpa, &.{ "nix", "path-info", "-rS", pkg });671}672673// --- Hash / Fetch ---674675pub fn nixHash(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine, path: []const u8) ![]u8 {676    const r = try capture(gpa, io, machine, &.{ "nix", "hash", "path", path });677    defer gpa.free(r.stderr);678    if (r.exit_code != 0) {679        gpa.free(r.stdout);680        return error.ProcessFailed;681    }682    return r.stdout;683}684685pub fn nixFetch(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine, url: []const u8) ![]u8 {686    const r = try capture(gpa, io, machine, &.{ "nix-prefetch-url", url });687    defer gpa.free(r.stderr);688    if (r.exit_code != 0) {689        gpa.free(r.stdout);690        return error.ProcessFailed;691    }692    return r.stdout;693}694695// --- Pin ---696697pub fn editFlakeLock(_: std.mem.Allocator, _: []const u8, _: []const u8) !void {698    // Stub: full implementation would parse and edit flake.lock JSON699    // The pin/unpin flow works via nix flake update which regenerates flake.lock700}701702pub fn openEditor(io: std.Io, gpa: std.mem.Allocator, editor: []const u8, path: []const u8, line: ?u32) !u8 {703    if (line) |l| {704        const line_arg = try std.fmt.allocPrint(gpa, "+{d}", .{l});705        defer gpa.free(line_arg);706        return stream(io, &types.Machine{}, gpa, &.{ editor, path, line_arg });707    }708    return stream(io, &types.Machine{}, gpa, &.{ editor, path });709}710711pub fn diffClosures(io: std.Io, machine: *const types.Machine, gpa: std.mem.Allocator, a: u32, b: u32) !u8 {712    const a_str = try std.fmt.allocPrint(gpa, "/nix/var/nix/profiles/system-{d}-link", .{a});713    defer gpa.free(a_str);714    const b_str = try std.fmt.allocPrint(gpa, "/nix/var/nix/profiles/system-{d}-link", .{b});715    defer gpa.free(b_str);716    // nix store diff-closures colorizes its own output. When nina's stdout isn't a717    // tty (piped/redirected), force NO_COLOR on the child so raw ANSI doesn't leak718    // into the piped text. `env` carries the var through SSH routing too.719    if (!output.colorEnabled()) {720        return stream(io, machine, gpa, &.{ "env", "NO_COLOR=1", "nix", "store", "diff-closures", a_str, b_str });721    }722    return stream(io, machine, gpa, &.{ "nix", "store", "diff-closures", a_str, b_str });723}724725// --- Doctor checks ---726727pub fn runDoctorChecks(gpa: std.mem.Allocator, io: std.Io, machine: *const types.Machine) ![]types.DoctorCheck {728    var checks: std.ArrayList(types.DoctorCheck) = .empty;729730    // Check nix daemon731    {732        const r = try capture(gpa, io, machine, &.{ "systemctl", "is-active", "nix-daemon" });733        defer gpa.free(r.stdout);734        defer gpa.free(r.stderr);735        const active = std.mem.indexOf(u8, r.stdout, "active") != null;736        try checks.append(gpa, .{ .name = "nix daemon", .status = if (active) .ok else .fail });737    }738739    // Check config syntax740    {741        const r = try capture(gpa, io, machine, &.{ "sudo", "nixos-rebuild", "dry-build" });742        defer gpa.free(r.stdout);743        defer gpa.free(r.stderr);744        try checks.append(gpa, .{ .name = "config syntax", .status = if (r.exit_code == 0) .ok else .fail });745    }746747    // Check channel748    {749        const r = try capture(gpa, io, machine, &.{ "nix-channel", "--list" });750        defer gpa.free(r.stdout);751        defer gpa.free(r.stderr);752        const has_channel = r.exit_code == 0 and r.stdout.len > 0;753        try checks.append(gpa, .{ .name = "channel", .status = if (has_channel) .ok else .warn });754    }755756    return checks.toOwnedSlice(gpa);757}758759// --- Log ---760761pub fn readNinaLog(gpa: std.mem.Allocator, io: std.Io, environ: *const std.process.Environ.Map, last: u32) ![]u8 {762    const home = environ.get("HOME") orelse return error.FileNotFound;763    const path = try std.fmt.allocPrint(gpa, "{s}/.nina.log", .{home});764    defer gpa.free(path);765    _ = last;766    return std.Io.Dir.readFileAlloc(.cwd(), io, path, gpa, .unlimited) catch return error.FileNotFound;767}768769// nina is a one-shot process, so "did the last apply fail this session?" can't770// live in memory — it's persisted as a ~/.nina-apply-failed flag, mirroring the771// other ~/.nina-* state files. This lets a later successful apply earn the772// excited kaomoji. mark sets it; take reads-and-clears so it fires exactly once.773pub fn markApplyFailed(io: std.Io, environ: *const std.process.Environ.Map) void {774    const home = environ.get("HOME") orelse return;775    var buf: [512]u8 = undefined;776    const path = std.fmt.bufPrint(&buf, "{s}/.nina-apply-failed", .{home}) catch return;777    const file = std.Io.Dir.createFile(.cwd(), io, path, .{}) catch return;778    file.close(io);779}780781pub fn takeApplyFailed(io: std.Io, environ: *const std.process.Environ.Map) bool {782    const home = environ.get("HOME") orelse return false;783    var buf: [512]u8 = undefined;784    const path = std.fmt.bufPrint(&buf, "{s}/.nina-apply-failed", .{home}) catch return false;785    if (std.Io.Dir.openFile(.cwd(), io, path, .{})) |f| {786        f.close(io);787        std.Io.Dir.deleteFile(.cwd(), io, path) catch {};788        return true;789    } else |_| {790        return false;791    }792}793794pub fn appendNinaLog(io: std.Io, environ: *const std.process.Environ.Map, entry: []const u8) void {795    const home = environ.get("HOME") orelse return;796    var path_buf: [512]u8 = undefined;797    const path = std.fmt.bufPrint(&path_buf, "{s}/.nina.log", .{home}) catch return;798    const file = std.Io.Dir.openFile(.cwd(), io, path, .{ .mode = .read_write }) catch799        (std.Io.Dir.createFile(.cwd(), io, path, .{}) catch return);800    defer file.close(io);801    const size = file.length(io) catch 0;802    file.writePositionalAll(io, entry, size) catch {};803}804805// --- Update helpers ---806807// Fetch a URL with curl and return the response body. Caller must free.808// error.NetworkError = DNS/connect failure; error.HttpError = non-2xx response.809pub fn fetchUrl(gpa: std.mem.Allocator, io: std.Io, url: []const u8) ![]u8 {810    const argv = [_][]const u8{811        "curl", "-s", "-L", "-w", "\nHTTP_STATUS:%{http_code}", "-m", "30", "--", url,812    };813    const result = std.process.run(gpa, io, .{ .argv = &argv }) catch return error.NetworkError;814    defer gpa.free(result.stderr);815816    const marker = "\nHTTP_STATUS:";817    const mark_idx = std.mem.lastIndexOf(u8, result.stdout, marker) orelse {818        gpa.free(result.stdout);819        return error.NetworkError;820    };821    const status_str = std.mem.trim(u8, result.stdout[mark_idx + marker.len ..], " \r\n");822    const status = std.fmt.parseInt(u16, status_str, 10) catch {823        gpa.free(result.stdout);824        return error.NetworkError;825    };826    if (status == 0) { gpa.free(result.stdout); return error.NetworkError; }827    if (status < 200 or status >= 300) { gpa.free(result.stdout); return error.HttpError; }828    const body = gpa.dupe(u8, result.stdout[0..mark_idx]) catch |e| {829        gpa.free(result.stdout);830        return e;831    };832    gpa.free(result.stdout);833    return body;834}835836// Download a URL to a temp file. Returns the temp path (caller must gpa.free).837// The file is written to /tmp/nina-update-<pid> and left for the caller to use.838pub fn downloadToTemp(gpa: std.mem.Allocator, io: std.Io, url: []const u8) ![]u8 {839    const tmp_path = try gpa.dupe(u8, "/tmp/nina-update.bin");840    errdefer gpa.free(tmp_path);841842    var child = std.process.spawn(io, .{843        .argv = &.{ "curl", "-fsSL", "-m", "300", "-o", tmp_path, "--", url },844        .stdin = .close,845        .stdout = .close,846        .stderr = .inherit,847    }) catch return error.NetworkError;848    const term = child.wait(io) catch return error.NetworkError;849    switch (term) {850        .exited => |c| if (c != 0) return error.NetworkError,851        else => return error.NetworkError,852    }853    return tmp_path;854}855856// Get the current executable path into buf. Returns slice of buf.857pub fn selfExePath(io: std.Io, buf: *[std.Io.Dir.max_path_bytes]u8) ![]const u8 {858    const len = try std.process.executablePath(io, buf);859    return buf[0..len];860}861862// Verify blake3 of tmp_path against expected_hex (raw hex, no prefix), then863// atomically install the binary to install_path. Errors: ChecksumMismatch,864// AccessDenied (with error_info set), or underlying I/O errors.865pub fn verifyAndInstall(gpa: std.mem.Allocator, io: std.Io, tmp_path: []const u8, expected_hex: []const u8, install_path: []const u8) !void {866    const bytes = std.Io.Dir.readFileAlloc(.cwd(), io, tmp_path, gpa, .unlimited) catch {867        errors.error_info.setMessage("downloaded file not found: {s}", .{tmp_path});868        return error.FileNotFound;869    };870    defer gpa.free(bytes);871872    var hasher = std.crypto.hash.Blake3.init(.{});873    hasher.update(bytes);874    var raw: [32]u8 = undefined;875    hasher.final(&raw);876    const hex = std.fmt.bytesToHex(raw, .lower);877    if (!std.mem.eql(u8, &hex, expected_hex)) return error.ChecksumMismatch;878879    var inst_tmp_buf: [std.Io.Dir.max_path_bytes + 8]u8 = undefined;880    const inst_tmp = std.fmt.bufPrint(&inst_tmp_buf, "{s}.new", .{install_path}) catch881        return error.NameTooLong;882883    {884        const f = std.Io.Dir.createFileAbsolute(io, inst_tmp, .{}) catch {885            errors.error_info.setMessage("cannot write to {s}", .{install_path});886            errors.error_info.setSuggestion("try: sudo nina update", .{});887            return error.AccessDenied;888        };889        defer f.close(io);890        f.writePositionalAll(io, bytes, 0) catch {891            errors.error_info.setMessage("cannot write to {s}", .{install_path});892            return error.AccessDenied;893        };894        try f.setPermissions(io, .fromMode(0o755));895    }896    errdefer std.Io.Dir.deleteFileAbsolute(io, inst_tmp) catch {};897898    if (comptime builtin.os.tag == .macos) {899        _ = captureLocal(gpa, io, &.{ "codesign", "-f", "-s", "-", inst_tmp }) catch {};900    }901902    std.Io.Dir.renameAbsolute(inst_tmp, install_path, io) catch |e| switch (e) {903        error.AccessDenied => {904            errors.error_info.setMessage("cannot replace {s}", .{install_path});905            errors.error_info.setSuggestion("try: sudo nina update", .{});906            return error.AccessDenied;907        },908        else => return e,909    };910}911912// --- Nix feature setup ---913914pub const NixFeatureStatus = struct {915    nix_command: bool = false,916    flakes: bool = false,917918    pub fn allEnabled(self: NixFeatureStatus) bool {919        return self.nix_command and self.flakes;920    }921};922923fn scanConfFeatures(conf: []const u8, status: *NixFeatureStatus) void {924    var lines = std.mem.splitScalar(u8, conf, '\n');925    while (lines.next()) |line| {926        const trimmed = std.mem.trim(u8, line, " \t");927        if (!std.mem.startsWith(u8, trimmed, "experimental-features")) continue;928        if (std.mem.indexOf(u8, trimmed, "nix-command") != null) status.nix_command = true;929        if (std.mem.indexOf(u8, trimmed, "flakes") != null) status.flakes = true;930    }931}932933pub fn checkNixFeatures(gpa: std.mem.Allocator, io: std.Io, environ: *const std.process.Environ.Map) NixFeatureStatus {934    var status = NixFeatureStatus{};935936    if (std.Io.Dir.readFileAlloc(.cwd(), io, "/etc/nix/nix.conf", gpa, .unlimited) catch null) |conf| {937        defer gpa.free(conf);938        scanConfFeatures(conf, &status);939    }940941    if (environ.get("HOME")) |home| {942        var buf: [512]u8 = undefined;943        const path = std.fmt.bufPrint(&buf, "{s}/.config/nix/nix.conf", .{home}) catch return status;944        if (std.Io.Dir.readFileAlloc(.cwd(), io, path, gpa, .unlimited) catch null) |conf| {945            defer gpa.free(conf);946            scanConfFeatures(conf, &status);947        }948    }949950    return status;951}952953pub fn isNixOS(io: std.Io) bool {954    const file = std.Io.Dir.openFile(.cwd(), io, "/etc/NIXOS", .{}) catch return false;955    file.close(io);956    return true;957}958959// Appends `experimental-features = nix-command flakes` to ~/.config/nix/nix.conf.960// Returns the path written (caller must free).961pub fn enableNixFeatures(gpa: std.mem.Allocator, io: std.Io, environ: *const std.process.Environ.Map) ![]const u8 {962    const home = environ.get("HOME") orelse {963        errors.error_info.setMessage("HOME not set", .{});964        return error.ConfigNotFound;965    };966967    const dir_path = try std.fmt.allocPrint(gpa, "{s}/.config/nix", .{home});968    defer gpa.free(dir_path);969    const file_path = try std.fmt.allocPrint(gpa, "{s}/.config/nix/nix.conf", .{home});970    errdefer gpa.free(file_path);971972    _ = captureLocal(gpa, io, &.{ "mkdir", "-p", dir_path }) catch {};973974    const line = "experimental-features = nix-command flakes\n";975    const file = std.Io.Dir.openFile(.cwd(), io, file_path, .{ .mode = .read_write }) catch976        (std.Io.Dir.createFile(.cwd(), io, file_path, .{}) catch {977        errors.error_info.setMessage("could not write {s}", .{file_path});978        return error.FileNotFound;979    });980    defer file.close(io);981982    const size = file.length(io) catch 0;983    file.writePositionalAll(io, line, size) catch {984        errors.error_info.setMessage("could not write {s}", .{file_path});985        return error.FileNotFound;986    };987988    return file_path;989}