api.zig

1// api.zig — nix data access: search, eval, options2// No HTTP. No curl. nix is on PATH by definition on NixOS.3const std = @import("std");4const types = @import("types.zig");5const errors = @import("errors.zig");6const output = @import("output.zig");78// Pin the nixpkgs registry once so `nix search nixpkgs` resolves locally instead9// of refetching github on every query. Gated by a ~/.nina-registry-pinned flag:10// absent -> pin + announce + create the flag; present -> no-op, silent. Failure11// to pin is non-fatal — search still runs (just slower), and the flag is left12// absent so a later run retries.13pub fn ensureRegistryPinned(gpa: std.mem.Allocator, io: std.Io, environ: *const std.process.Environ.Map) void {14    const home = environ.get("HOME") orelse return;15    const flag_path = std.fmt.allocPrint(gpa, "{s}/.nina-registry-pinned", .{home}) catch return;16    defer gpa.free(flag_path);1718    if (std.Io.Dir.openFile(.cwd(), io, flag_path, .{})) |f| {19        f.close(io);20        return; // already pinned21    } else |_| {}2223    output.pinningRegistry();2425    const r = std.process.run(gpa, io, .{26        .argv = &.{ "nix", "registry", "pin", "nixpkgs" },27    }) catch return;28    defer gpa.free(r.stdout);29    defer gpa.free(r.stderr);30    switch (r.term) {31        .exited => |code| if (code != 0) return,32        else => return,33    }3435    const file = std.Io.Dir.createFile(.cwd(), io, flag_path, .{}) catch return;36    file.close(io);37}3839pub fn searchPackages(gpa: std.mem.Allocator, io: std.Io, environ: *const std.process.Environ.Map, query: []const u8) ![]types.NixPackage {40    const result = std.process.run(gpa, io, .{41        .argv = &.{ "nix", "search", "nixpkgs", query, "--json", "--no-update-lock-file" },42    }) catch {43        errors.error_info.setSuggestion("run nix-channel --update and try again", .{});44        return error.SearchFailed;45    };46    defer gpa.free(result.stderr);47    defer gpa.free(result.stdout);4849    switch (result.term) {50        .exited => |code| if (code != 0) {51            // nix evaluates nixpkgs.legacyPackages during search and rejects unfree52            // packages even when the user has allowUnfree set system-wide. Retry53            // with NIXPKGS_ALLOW_UNFREE=1 so the package appears in results, and54            // tag it so the install step can pass the same override.55            if (isSearchUnfreeError(result.stderr)) {56                return searchPackagesUnfree(gpa, io, environ, query);57            }58            errors.error_info.setSuggestion("run nix-channel --update and try again", .{});59            return error.SearchFailed;60        },61        else => return error.SearchFailed,62    }6364    return parseSearchJson(gpa, result.stdout, false);65}6667fn isSearchUnfreeError(stderr: []const u8) bool {68    return std.mem.indexOf(u8, stderr, "requires unfree license") != null or69        std.mem.indexOf(u8, stderr, "has an unfree license") != null;70}7172fn searchPackagesUnfree(gpa: std.mem.Allocator, io: std.Io, environ: *const std.process.Environ.Map, query: []const u8) ![]types.NixPackage {73    var env = try environ.clone(gpa);74    defer env.deinit();75    try env.put("NIXPKGS_ALLOW_UNFREE", "1");7677    const result = std.process.run(gpa, io, .{78        // --impure allows builtins.getEnv in nixpkgs's unfree check to read79        // NIXPKGS_ALLOW_UNFREE from the environment; pure flake eval ignores it.80        .argv = &.{ "nix", "search", "nixpkgs", query, "--json", "--no-update-lock-file", "--impure" },81        .environ_map = &env,82    }) catch {83        errors.error_info.setSuggestion("run nix-channel --update and try again", .{});84        return error.SearchFailed;85    };86    defer gpa.free(result.stderr);87    defer gpa.free(result.stdout);8889    switch (result.term) {90        .exited => |code| if (code != 0) {91            errors.error_info.setSuggestion("run nix-channel --update and try again", .{});92            return error.SearchFailed;93        },94        else => return error.SearchFailed,95    }9697    return parseSearchJson(gpa, result.stdout, true);98}99100fn parseSearchJson(gpa: std.mem.Allocator, json_str: []const u8, unfree: bool) ![]types.NixPackage {101    const parsed = std.json.parseFromSlice(std.json.Value, gpa, json_str, .{}) catch return error.SearchFailed;102    defer parsed.deinit();103104    if (parsed.value != .object) return error.SearchFailed;105106    var packages: std.ArrayList(types.NixPackage) = .empty;107    var it = parsed.value.object.iterator();108    while (it.next()) |entry| {109        const key = entry.key_ptr.*;110        const val = entry.value_ptr.*;111        if (val != .object) continue;112113        // Key format: "legacyPackages.x86_64-linux.firefox"114        const last_dot = std.mem.lastIndexOfScalar(u8, key, '.') orelse continue;115        const attr = key[last_dot + 1 ..];116117        const pname = if (val.object.get("pname")) |v|118            if (v == .string) v.string else attr119        else120            attr;121122        const version = if (val.object.get("version")) |v|123            if (v == .string) v.string else ""124        else125            "";126127        const description = if (val.object.get("description")) |v|128            if (v == .string) v.string else ""129        else130            "";131132        try packages.append(gpa, .{133            .attr = try gpa.dupe(u8, attr),134            .pname = try gpa.dupe(u8, pname),135            .version = try gpa.dupe(u8, version),136            .description = try gpa.dupe(u8, description),137            .unfree = unfree,138        });139    }140141    return packages.toOwnedSlice(gpa);142}143144pub const PkgMeta = struct {145    homepage: []const u8 = "",146    license: []const u8 = "",147};148149// Evaluate a package's meta for the expanded search detail pane. One150// `nix eval --json .meta` call; returns null if the package can't be evaluated151// (broken, renamed, etc.). Returned strings are duped into `arena`.152pub fn packageMeta(arena: std.mem.Allocator, io: std.Io, attr: []const u8) ?PkgMeta {153    const ref = std.fmt.allocPrint(arena, "nixpkgs#{s}.meta", .{attr}) catch return null;154    const result = std.process.run(arena, io, .{155        .argv = &.{ "nix", "eval", "--json", ref },156    }) catch return null;157    switch (result.term) {158        .exited => |code| if (code != 0) return null,159        else => return null,160    }161    const parsed = std.json.parseFromSlice(std.json.Value, arena, result.stdout, .{}) catch return null;162    defer parsed.deinit();163    if (parsed.value != .object) return null;164    const o = parsed.value.object;165    return .{166        .homepage = jsonFirstString(arena, o.get("homepage")),167        .license = licenseStr(arena, o.get("license")),168    };169}170171// homepage is usually a string but occasionally a list — take the first string.172fn jsonFirstString(arena: std.mem.Allocator, v: ?std.json.Value) []const u8 {173    const val = v orelse return "";174    switch (val) {175        .string => |s| return arena.dupe(u8, s) catch "",176        .array => |arr| {177            if (arr.items.len > 0 and arr.items[0] == .string) return arena.dupe(u8, arr.items[0].string) catch "";178            return "";179        },180        else => return "",181    }182}183184// license may be a single attrset, a list of attrsets, or a bare string. Join the185// fullName (or shortName) fields into one readable line. Result is duped into arena.186fn licenseStr(arena: std.mem.Allocator, v: ?std.json.Value) []const u8 {187    const val = v orelse return "";188    switch (val) {189        .string => |s| return arena.dupe(u8, s) catch "",190        .object => |obj| return arena.dupe(u8, licenseName(obj)) catch "",191        .array => |arr| {192            var buf: std.ArrayList(u8) = .empty;193            for (arr.items) |item| {194                if (item != .object) continue;195                const name = licenseName(item.object);196                if (name.len == 0) continue;197                if (buf.items.len > 0) buf.appendSlice(arena, ", ") catch {};198                buf.appendSlice(arena, name) catch {};199            }200            return buf.toOwnedSlice(arena) catch "";201        },202        else => return "",203    }204}205206// Returns a slice into the parsed JSON arena (caller dupes before that frees).207fn licenseName(obj: std.json.ObjectMap) []const u8 {208    if (obj.get("fullName")) |n| {209        if (n == .string) return n.string;210    }211    if (obj.get("shortName")) |n| {212        if (n == .string) return n.string;213    }214    return "";215}216217// nix eval takes exactly one installable/expression and its result must be218// JSON-serializable, so (unlike searchPackages) this can't point straight at a219// flake attribute: lib.optionAttrSetToDocList is a function, not a value, and220// nixpkgs#nixosModules isn't an output path nix eval can resolve at all. This221// builds a minimal NixOS system from an empty module list and feeds its222// accumulated options tree to optionAttrSetToDocList ourselves — the same223// technique nixos-option and the NixOS manual generator use. --impure is224// required for builtins.getFlake on the bare registry name and for225// builtins.currentSystem.226//227// NOTE: not exercised against real nix (none available on this host/dev228// machine); verified only via the fixture-driven parsing test below against229// hand-written JSON shaped like optionAttrSetToDocList's documented output.230// Needs a real-host / VM run before this is considered fully resolved.231const OPTIONS_DOC_LIST_EXPR =232    \\let233    \\  flake = builtins.getFlake "nixpkgs";234    \\  eval = flake.lib.nixosSystem {235    \\    system = builtins.currentSystem;236    \\    modules = [ { } ];237    \\  };238    \\in239    \\  flake.lib.optionAttrSetToDocList eval.options240;241242pub fn searchOptions(gpa: std.mem.Allocator, io: std.Io, query: []const u8) ![]NixOption {243    const result = std.process.run(gpa, io, .{244        .argv = &.{ "nix", "eval", "--json", "--impure", "--expr", OPTIONS_DOC_LIST_EXPR },245    }) catch return error.SearchFailed;246    defer gpa.free(result.stderr);247    defer gpa.free(result.stdout);248249    switch (result.term) {250        .exited => |code| if (code != 0) return error.SearchFailed,251        else => return error.SearchFailed,252    }253254    return filterOptions(gpa, result.stdout, query);255}256257pub const NixOption = struct {258    name: []const u8,259    type_str: []const u8,260    default: ?[]const u8,261    description: []const u8,262};263264// optionAttrSetToDocList's "default" field is a plain string on older265// nixpkgs, or a { _type = "literalExpression"; text = "..."; } wrapper on266// nixos-render-docs era nixpkgs. Handle both; anything else (e.g. a267// submodule's structured default) renders as "no default" rather than268// guessing at a representation.269fn optionDefaultText(v: std.json.Value) ?[]const u8 {270    return switch (v) {271        .string => |s| s,272        .object => |obj| if (obj.get("text")) |t| (if (t == .string) t.string else null) else null,273        else => null,274    };275}276277fn filterOptions(gpa: std.mem.Allocator, json_str: []const u8, query: []const u8) ![]NixOption {278    const parsed = std.json.parseFromSlice(std.json.Value, gpa, json_str, .{}) catch return error.SearchFailed;279    defer parsed.deinit();280281    if (parsed.value != .array) return error.SearchFailed;282283    var opts: std.ArrayList(NixOption) = .empty;284    for (parsed.value.array.items) |item| {285        if (item != .object) continue;286        const name = if (item.object.get("name")) |v| if (v == .string) v.string else continue else continue;287        if (query.len > 0 and std.mem.indexOf(u8, name, query) == null) continue;288289        const type_str = if (item.object.get("type")) |v| if (v == .string) v.string else "any" else "any";290        const description = if (item.object.get("description")) |v| if (v == .string) v.string else "" else "";291        const default_val: ?[]const u8 = if (item.object.get("default")) |v| optionDefaultText(v) else null;292293        try opts.append(gpa, .{294            .name = try gpa.dupe(u8, name),295            .type_str = try gpa.dupe(u8, type_str),296            .default = if (default_val) |d| try gpa.dupe(u8, d) else null,297            .description = try gpa.dupe(u8, description),298        });299    }300301    return opts.toOwnedSlice(gpa);302}303304pub fn findSystemPackagesLine(io: std.Io, config_path: []const u8) ?u32 {305    var buf: [65536]u8 = undefined;306    const content = std.Io.Dir.readFile(.cwd(), io, config_path, &buf) catch return null;307    var lines = std.mem.splitScalar(u8, content, '\n');308    var line_num: u32 = 1;309    while (lines.next()) |line| : (line_num += 1) {310        if (std.mem.indexOf(u8, line, "systemPackages") != null) return line_num;311    }312    return null;313}314315// ─── Tests ───────────────────────────────────────────────────────────────────316//317// searchOptions itself is not exercised here (no nix on this host); these318// pin filterOptions's parsing against JSON shaped like optionAttrSetToDocList's319// real output (NINA-009), covering both the modern literalExpression-wrapped320// default and the older plain-string default.321322test "filterOptions extracts a known option from realistic doc-list JSON (NINA-009)" {323    const fixture =324        \\[325        \\  {326        \\    "name": "services.openssh.enable",327        \\    "type": "boolean",328        \\    "default": { "_type": "literalExpression", "text": "false" },329        \\    "description": "Whether to enable the OpenSSH secure shell daemon."330        \\  },331        \\  {332        \\    "name": "services.nginx.enable",333        \\    "type": "boolean",334        \\    "default": { "_type": "literalExpression", "text": "false" },335        \\    "description": "Whether to enable nginx."336        \\  }337        \\]338    ;339340    const opts = try filterOptions(std.testing.allocator, fixture, "openssh");341    defer {342        for (opts) |o| {343            std.testing.allocator.free(o.name);344            std.testing.allocator.free(o.type_str);345            std.testing.allocator.free(o.description);346            if (o.default) |d| std.testing.allocator.free(d);347        }348        std.testing.allocator.free(opts);349    }350351    try std.testing.expectEqual(@as(usize, 1), opts.len);352    try std.testing.expectEqualStrings("services.openssh.enable", opts[0].name);353    try std.testing.expectEqualStrings("boolean", opts[0].type_str);354    try std.testing.expect(opts[0].default != null);355    try std.testing.expectEqualStrings("false", opts[0].default.?);356    try std.testing.expect(std.mem.indexOf(u8, opts[0].description, "OpenSSH") != null);357}358359test "filterOptions still reads a plain-string default (pre-literalExpression nixpkgs)" {360    const fixture =361        \\[362        \\  {363        \\    "name": "services.openssh.ports",364        \\    "type": "list of signed integer",365        \\    "default": "[ 22 ]",366        \\    "description": "Ports on which to listen."367        \\  }368        \\]369    ;370371    const opts = try filterOptions(std.testing.allocator, fixture, "");372    defer {373        for (opts) |o| {374            std.testing.allocator.free(o.name);375            std.testing.allocator.free(o.type_str);376            std.testing.allocator.free(o.description);377            if (o.default) |d| std.testing.allocator.free(d);378        }379        std.testing.allocator.free(opts);380    }381382    try std.testing.expectEqual(@as(usize, 1), opts.len);383    try std.testing.expectEqualStrings("[ 22 ]", opts[0].default.?);384}385386test "filterOptions returns no match for a query that isn't a substring of any option name" {387    const fixture =388        \\[389        \\  { "name": "services.openssh.enable", "type": "boolean", "default": null, "description": "" }390        \\]391    ;392393    const opts = try filterOptions(std.testing.allocator, fixture, "postgres");394    defer std.testing.allocator.free(opts);395    try std.testing.expectEqual(@as(usize, 0), opts.len);396}