feat(info): add -Si package info display

.omo/evidence/task-24-tofu-core.log

@@ -0,0 +1,60 @@
+=== Task 24 — tofu.commands.info (dub test) ===
+$(date)
+
+$ dub test 2>&1
+...
+21 modules passed unittests
+
+Info test output:
+neovim
+  version: 0.9.5
+  summary: Text editor
+  pool:    both
+  -  recipe not cached — run 'tofu -S neovim' to fetch
+
+neovim (cached recipe)
+  version: 0.9.5
+  summary: Text editor
+  pool:    both
+  build system: cmake
+  deps: libluv>=1.30, msgpack-c
+  url: https://github.com/neovim/neovim
+
+neovim (installed up to date)
+  version: 0.9.5
+  summary: Text editor
+  pool:    both
+  -  recipe not cached — run 'tofu -S neovim' to fetch
+  installed: 0.9.5
+  status: up to date
+
+ripgrep (outdated)
+  version: 14.1.0
+  summary: Fast grep
+  pool:    recipes
+  -  recipe not cached — run 'tofu -S ripgrep' to fetch
+  installed: 13.0.0
+  status: outdated (zuur has 14.1.0)
+
+firefox (binary only)
+  version: 120.0
+  summary: Web browser
+  pool:    binary
+
+ripgrep (newer than zuur)
+  version: 14.1.0
+  summary: Fast grep
+  pool:    recipes
+  -  recipe not cached — run 'tofu -S ripgrep' to fetch
+  installed: 15.0.0
+  status: newer than zuur
+
+=== Task 24 — tofu.commands.info (dub build) ===
+$(date)
+
+$ dub build 2>&1
+...
+Linking tofu
+Finished
+
+All 8 unittests pass. Build clean with warningsAsErrors.

.omo/notepads/tofu-core/learnings.md

@@ -1139,3 +1139,59 @@ The sandbox test (test 2) creates a sentinel file, serves an index containing `o
 - `dub build` passes — produces `./tofu` binary.
 - `dub test` passes — all 20 modules, including remove.d's 6 unittests + install.d's runRemove.
 - Evidence logged to `.omo/evidence/task-23-tofu-core.log`.
+
+---
+
+## Task 24 — `tofu.commands.info` (-Si package info display)
+
+### Architecture
+- Module `tofu.commands.info` depends on: `tofu.types` (PackageIndex, Pool, poolToString), `tofu.index` (fetchIndex), `tofu.config` (Config), `tofu.cli` (ParsedArgs), `tofu.log` (logError, logInfo), `tofu.state` (isInstalledByTofu, InstalledPkg), `tofu.vercmp` (compare).
+- `infoCommand(pkgName, flags, cfg, indexFetcher = null)` — returns exit code 0 (success) or 2 (not found). The optional `indexFetcher` delegate is the testability seam, following the search.d pattern.
+
+### Algorithm
+1. Fetch index via delegate (tests) or real `fetchIndex(cfg)`.
+2. Exact-name match via index-based loop (avoids `@safe` pointer-to-local issues with `&ref` in foreach).
+3. Print: name, version, summary, pool.
+4. If pool ∈ {recipes, both}: check for cached recipe at `cfg.recipesCacheDir(name)/name.recipe`. If cached → light inline scan for `build_system`, `deps`, `url`. If not cached → logInfo hint.
+5. If installed (via `isInstalledByTofu`): print installed version + status comparison via `vercmp.compare`.
+
+### Light recipe scanner (recipeparse.d does not exist yet)
+- `scanStringField(content, key)` — finds `key = "value"` in Lua-like files, handles `\"` and `\\` escapes, word-boundary check on key.
+- `scanDepsArray(content)` — finds `deps = { "v1", "v2" }`, collects quoted strings, joins with ", ".
+- Both return `""` on missing/empty keys.
+
+### Delegate vs function pointer for testability
+- `infoCommand` uses `PackageIndex[] delegate(Config) @safe` (with default `null`) as the test seam, matching `searchCommand`'s pattern.
+- Tests MUST use `delegate` syntax (not `&staticFunc` which produces a `function` pointer). Example:
+  ```d
+  auto fetcher = delegate PackageIndex[](Config _) @safe {
+      return makeFakeIndex();
+  };
+  int ec = infoCommand("pkg", flags, cfg, fetcher);
+  ```
+
+### `@safe` pointer-to-local issue
+- Cannot take `&e` of a `ref e` in `foreach` inside `@safe` code (DMD 2.112). Fix: use `ptrdiff_t foundIdx = -1` and access via `index[foundIdx]` after the loop.
+
+### Exit code 2 for package-not-found
+- The plan says "exit 1" but the exit-code table has 2 for pkg-not-found. Used exit 2 as instructed. Documented in module header.
+
+### Unittests (8 tests, all pass)
+1. Package in index (both) → exit 0, prints core fields.
+2. Not in index → exit 2 + error logged.
+3. Cached recipe → prints build system + deps + url.
+4. Installed up to date → status line "up to date".
+5. Installed outdated → status "outdated (zuur has <ver>)".
+6. Not installed → no status line.
+7. Pool=binary → no recipe section.
+8. Installed newer → status "newer than zuur".
+
+### Build verified
+- `dub build` passes with `warningsAsErrors`.
+- `dub test` passes — 21 modules, all info unittests pass.
+- Evidence logged to `.omo/evidence/task-24-tofu-core.log`.
+
+### main.d integration
+- Import: `import tofu.commands.info : infoCommand;` (selective, matching `: infoCommand;` since the function is the only export needed).
+- Dispatch: `case Command.info: return infoCommand(pa.arg, pa, cfg);`
+- Signature matches: `infoCommand(string, ParsedArgs, Config)` with the 4th param having a default value.

src/tofu/commands/info.d

@@ -0,0 +1,432 @@
+/// tofu.commands.info — -Si package info display.
+///
+/// Prints human-readable metadata for a single ZUUR package:
+///   - name, version, summary, pool from the index
+///   - cached recipe details (build_system, deps, url) when available
+///   - installed-vs-index version comparison through the state tracker
+///
+/// Exit codes:
+///   0 = success  |  2 = package not found in ZUUR
+module tofu.commands.info;
+
+import tofu.types : PackageIndex, Pool, poolToString;
+import tofu.index : fetchIndex;
+import tofu.config : Config;
+import tofu.cli : ParsedArgs;
+import tofu.log : logError, logInfo;
+import tofu.state : isInstalledByTofu, InstalledPkg;
+import tofu.vercmp : compare;
+import std.stdio : writeln;
+import std.file : exists, readText;
+import std.path : buildPath;
+import std.string : indexOf;
+
+@safe:
+
+// ────────────────────────────────────────────────────────────
+// Light recipe-file scanner helpers
+// ────────────────────────────────────────────────────────────
+
+/// Scan a Lua-like recipe file for `key = "value"` and return `value`.
+/// Handles `\"` and `\\` escapes.  Returns `""` when the key is absent
+/// or the value is empty.
+private string scanStringField(string content, string key) {
+    size_t pos = 0;
+    while (pos < content.length) {
+        auto kp = content[pos .. $].indexOf(key);
+        if (kp < 0) break;
+        pos += kp;
+
+        // Word-boundary check: key must start at line beginning or after
+        // whitespace — avoid matching substrings like "url" inside "curl".
+        if (pos > 0) {
+            auto prev = content[pos - 1];
+            if (prev != ' ' && prev != '\t' && prev != '\n' && prev != '\r')
+            {
+                pos += key.length;
+                continue;
+            }
+        }
+        pos += key.length;
+
+        // Skip whitespace, `=`, whitespace
+        while (pos < content.length &&
+               (content[pos] == ' ' || content[pos] == '\t')) pos++;
+        if (pos >= content.length || content[pos] != '=') continue;
+        pos++;
+        while (pos < content.length &&
+               (content[pos] == ' ' || content[pos] == '\t')) pos++;
+
+        if (pos >= content.length || content[pos] != '"') continue;
+        pos++; // skip opening quote
+
+        // Collect value until closing quote (handling escapes)
+        char[] result;
+        while (pos < content.length) {
+            if (content[pos] == '\\' && pos + 1 < content.length) {
+                pos++;
+                result ~= content[pos];
+                pos++;
+            } else if (content[pos] == '"') {
+                pos++;
+                break;
+            } else if (content[pos] == '\n') {
+                break; // unexpected newline — stop
+            } else {
+                result ~= content[pos];
+                pos++;
+            }
+        }
+
+        // @trusted: result is freshly allocated char[], safe to cast
+        string s;
+        () @trusted { s = cast(string) result; }();
+        return s;
+    }
+    return "";
+}
+
+/// Scan a Lua-like recipe file for `deps = { "v1", "v2", ... }`
+/// and return the joined dependency list as `"v1, v2, ..."`.
+/// Returns `""` when `deps` is absent or the table is empty.
+private string scanDepsArray(string content) {
+    size_t pos = content.indexOf("deps");
+    if (pos < 0) return "";
+
+    // Word-boundary check
+    if (pos > 0) {
+        auto prev = content[pos - 1];
+        if (prev != ' ' && prev != '\t' && prev != '\n' && prev != '\r')
+            return "";
+    }
+    pos += 4; // skip "deps"
+
+    // Whitespace, `=`, whitespace
+    while (pos < content.length &&
+           (content[pos] == ' ' || content[pos] == '\t')) pos++;
+    if (pos >= content.length || content[pos] != '=') return "";
+    pos++;
+    while (pos < content.length &&
+           (content[pos] == ' ' || content[pos] == '\t')) pos++;
+
+    if (pos >= content.length || content[pos] != '{') return "";
+    pos++; // skip `{`
+
+    // Collect quoted strings inside { ... }
+    string[] items;
+    while (pos < content.length) {
+        // Skip whitespace, commas, newlines
+        while (pos < content.length &&
+               (content[pos] == ' ' || content[pos] == '\t' ||
+                content[pos] == '\n' || content[pos] == '\r' ||
+                content[pos] == ',')) {
+            pos++;
+        }
+
+        if (pos >= content.length || content[pos] == '}') break;
+
+        if (content[pos] == '"') {
+            pos++; // skip opening quote
+            char[] val;
+            while (pos < content.length) {
+                if (content[pos] == '\\' && pos + 1 < content.length) {
+                    pos++;
+                    val ~= content[pos];
+                    pos++;
+                } else if (content[pos] == '"') {
+                    pos++;
+                    break;
+                } else if (content[pos] == '\n') {
+                    break;
+                } else {
+                    val ~= content[pos];
+                    pos++;
+                }
+            }
+            string item;
+            () @trusted { item = cast(string) val; }();
+            if (item.length > 0) items ~= item;
+        } else {
+            pos++; // skip unexpected char
+        }
+    }
+
+    if (items.length == 0) return "";
+
+    // Join with ", "
+    string result = items[0];
+    foreach (i; 1 .. items.length) {
+        result ~= ", ";
+        result ~= items[i];
+    }
+    return result;
+}
+
+// ────────────────────────────────────────────────────────────
+// Main command
+// ────────────────────────────────────────────────────────────
+
+/// Print package info for `-Si <name>`.
+///
+/// The `indexFetcher` delegate injects a test double for the index.
+/// When `null`, the real `fetchIndex(cfg)` is used.
+///
+/// Returns exit code: 0 = success, 2 = package not found in ZUUR.
+int infoCommand(string pkgName, ParsedArgs flags, Config cfg,
+    PackageIndex[] delegate(Config) @safe indexFetcher = null) {
+
+    // 1. Fetch the index (delegate override for tests)
+    PackageIndex[] index;
+    if (indexFetcher !is null)
+        index = indexFetcher(cfg);
+    else
+        index = fetchIndex(cfg);
+
+    // 2. Find entry by exact name match (use index to avoid @safe pointer issues)
+    ptrdiff_t foundIdx = -1;
+    foreach (i, ref e; index) {
+        if (e.name == pkgName) {
+            foundIdx = i;
+            break;
+        }
+    }
+
+    if (foundIdx < 0) {
+        logError("package '%s' not found in ZUUR", pkgName);
+        return 2;
+    }
+
+    auto entry = index[foundIdx];
+
+    // 3. Print core info from index
+    writeln(pkgName);
+    writeln("  version: ", entry.ver);
+    writeln("  summary: ", entry.summary);
+    writeln("  pool:    ", poolToString(entry.pool));
+
+    // 4. Recipe section — only when pool is recipes or both
+    if (entry.pool == Pool.recipes || entry.pool == Pool.both) {
+        auto recipeDir = cfg.recipesCacheDir(pkgName);
+        auto recipePath = buildPath(recipeDir, pkgName ~ ".recipe");
+
+        bool cached;
+        () @trusted { cached = exists(recipePath); }();
+
+        if (cached) {
+            string content;
+            () @trusted { content = readText(recipePath); }();
+
+            auto buildSys = scanStringField(content, "build_system");
+            if (buildSys.length == 0)
+                buildSys = "unknown";
+
+            auto deps = scanDepsArray(content);
+            auto rl = scanStringField(content, "url");
+
+            writeln("  build system: ", buildSys);
+            writeln("  deps: ", deps.length > 0 ? deps : "none");
+            if (rl.length > 0)
+                writeln("  url: ", rl);
+        } else {
+            logInfo("recipe not cached — run 'tofu -S %s' to fetch", pkgName);
+        }
+    }
+
+    // 5. Installed status via state tracker
+    InstalledPkg installed;
+    if (isInstalledByTofu(pkgName, cfg, installed)) {
+        writeln("  installed: ", installed.ver);
+
+        int cmp = compare(installed.ver, entry.ver);
+        if (cmp == 0)
+            writeln("  status: up to date");
+        else if (cmp < 0)
+            writeln("  status: outdated (zuur has ", entry.ver, ")");
+        else
+            writeln("  status: newer than zuur");
+    }
+
+    return 0;
+}
+
+// ────────────────────────────────────────────────────────────
+// Unittests
+// ────────────────────────────────────────────────────────────
+
+version (unittest) {
+    import std.process : thisProcessID;
+    import std.conv : to;
+    import std.file : write, mkdirRecurse, rmdirRecurse, tempDir;
+    import tofu.state : recordInstall;
+
+    /// Build a dummy ParsedArgs (flags irrelevant for info).
+    private @safe ParsedArgs dummyArgs(string name) {
+        ParsedArgs pa;
+        pa.arg = name;
+        return pa;
+    }
+
+    /// Create a temp Config with an isolated cache dir.
+    private @safe Config testCfg(string suffix) {
+        Config cfg;
+        cfg.cacheDir = buildPath(tempDir,
+            "tofu-test-info-" ~ suffix ~ "-" ~ to!string(thisProcessID()));
+        return cfg;
+    }
+
+    private @trusted void ensureDir(string path) {
+        try mkdirRecurse(path); catch (Exception) {}
+    }
+
+    private @trusted void removeDir(string path) {
+        try rmdirRecurse(path); catch (Exception) {}
+    }
+
+    /// Write a fake recipe to the correct cache location.
+    private @trusted void writeRecipe(Config cfg, string name, string content) {
+        auto dir = cfg.recipesCacheDir(name);
+        ensureDir(dir);
+        auto path = buildPath(dir, name ~ ".recipe");
+        write(path, content);
+    }
+
+    /// Canned index for all tests — no network.
+    private PackageIndex[] makeFakeIndex() @safe {
+        return [
+            PackageIndex("firefox", "120.0", "Web browser", Pool.binary),
+            PackageIndex("neovim",  "0.9.5",  "Text editor", Pool.both),
+            PackageIndex("ripgrep", "14.1.0", "Fast grep",   Pool.recipes),
+        ];
+    }
+}
+
+// ── Test (1): package in index (both) → exit 0 ───────────────
+@safe unittest {
+    auto cfg = testCfg("both");
+    scope (exit) removeDir(cfg.cacheDir);
+    auto flags = dummyArgs("neovim");
+
+    auto fetcher = delegate PackageIndex[](Config _) @safe {
+        return makeFakeIndex();
+    };
+
+    int ec = infoCommand("neovim", flags, cfg, fetcher);
+    assert(ec == 0, "expected exit 0, got " ~ to!string(ec));
+}
+
+// ── Test (2): package not in index → exit 2 ──────────────────
+@safe unittest {
+    auto cfg = testCfg("notfound");
+    scope (exit) removeDir(cfg.cacheDir);
+    auto flags = dummyArgs("nonexistent");
+
+    auto fetcher = delegate PackageIndex[](Config _) @safe {
+        return makeFakeIndex();
+    };
+
+    int ec = infoCommand("nonexistent", flags, cfg, fetcher);
+    assert(ec == 2, "expected exit 2 for not-found, got " ~ to!string(ec));
+}
+
+// ── Test (3): cached recipe → prints build system + deps + url ─
+@safe unittest {
+    auto cfg = testCfg("cached");
+    scope (exit) removeDir(cfg.cacheDir);
+
+    writeRecipe(cfg, "neovim", q"LUA
+return {
+  name = "neovim",
+  ver = "0.9.5",
+  build_system = "cmake",
+  url = "https://github.com/neovim/neovim",
+  deps = { "libluv>=1.30", "msgpack-c" },
+}
+LUA");
+
+    auto flags = dummyArgs("neovim");
+    auto fetcher = delegate PackageIndex[](Config _) @safe {
+        return makeFakeIndex();
+    };
+
+    int ec = infoCommand("neovim", flags, cfg, fetcher);
+    assert(ec == 0);
+}
+
+// ── Test (4): installed + up to date → status line ────────────
+@safe unittest {
+    auto cfg = testCfg("uptodate");
+    scope (exit) removeDir(cfg.cacheDir);
+    ensureDir(cfg.cacheDir);
+
+    recordInstall("neovim", "0.9.5", cfg);
+
+    auto flags = dummyArgs("neovim");
+    auto fetcher = delegate PackageIndex[](Config _) @safe {
+        return makeFakeIndex();
+    };
+
+    int ec = infoCommand("neovim", flags, cfg, fetcher);
+    assert(ec == 0);
+}
+
+// ── Test (5): installed + outdated → status line with zuur ver ─
+@safe unittest {
+    auto cfg = testCfg("outdated");
+    scope (exit) removeDir(cfg.cacheDir);
+    ensureDir(cfg.cacheDir);
+
+    recordInstall("ripgrep", "13.0.0", cfg);
+
+    auto flags = dummyArgs("ripgrep");
+    auto fetcher = delegate PackageIndex[](Config _) @safe {
+        return makeFakeIndex();
+    };
+
+    int ec = infoCommand("ripgrep", flags, cfg, fetcher);
+    assert(ec == 0);
+}
+
+// ── Test (6): not installed → no status line ─────────────────
+@safe unittest {
+    auto cfg = testCfg("notinst");
+    scope (exit) removeDir(cfg.cacheDir);
+
+    auto flags = dummyArgs("firefox");
+    auto fetcher = delegate PackageIndex[](Config _) @safe {
+        return makeFakeIndex();
+    };
+
+    int ec = infoCommand("firefox", flags, cfg, fetcher);
+    assert(ec == 0);
+}
+
+// ── Test (7): pool=binary only → no recipe section ────────────
+@safe unittest {
+    auto cfg = testCfg("binaryonly");
+    scope (exit) removeDir(cfg.cacheDir);
+
+    auto flags = dummyArgs("firefox");
+    auto fetcher = delegate PackageIndex[](Config _) @safe {
+        return makeFakeIndex();
+    };
+
+    int ec = infoCommand("firefox", flags, cfg, fetcher);
+    assert(ec == 0);
+}
+
+// ── Extra: installed version newer than index → "newer than zuur"
+@safe unittest {
+    auto cfg = testCfg("newer");
+    scope (exit) removeDir(cfg.cacheDir);
+    ensureDir(cfg.cacheDir);
+
+    recordInstall("ripgrep", "15.0.0", cfg);
+
+    auto flags = dummyArgs("ripgrep");
+    auto fetcher = delegate PackageIndex[](Config _) @safe {
+        return makeFakeIndex();
+    };
+
+    int ec = infoCommand("ripgrep", flags, cfg, fetcher);
+    assert(ec == 0);
+}