From 8214471e2c3d3085829a126ca6e7de6bb9e70a03 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Sat, 23 Sep 2023 22:59:22 -0700
Subject: [PATCH] cli/list-fonts: dumb implementation

---
 src/cli/action.zig     |  3 +--
 src/cli/args.zig       |  2 +-
 src/cli/list_fonts.zig | 60 +++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 61 insertions(+), 4 deletions(-)

diff --git a/src/cli/action.zig b/src/cli/action.zig
index 26b3988be..4151d7aa2 100644
--- a/src/cli/action.zig
+++ b/src/cli/action.zig
@@ -49,10 +49,9 @@ pub const Action = enum {
 
     /// Run the action. This returns the exit code to exit with.
     pub fn run(self: Action, alloc: Allocator) !u8 {
-        _ = alloc;
         return switch (self) {
             .version => try version.run(),
-            .@"list-fonts" => try list_fonts.run(),
+            .@"list-fonts" => try list_fonts.run(alloc),
         };
     }
 };
diff --git a/src/cli/args.zig b/src/cli/args.zig
index 0a326fe89..833914c88 100644
--- a/src/cli/args.zig
+++ b/src/cli/args.zig
@@ -55,7 +55,7 @@ pub fn parse(comptime T: type, alloc: Allocator, dst: *T, iter: anytype) !void {
         break :arena dst._arena.?.allocator();
     } else fail: {
         // Note: this is... not safe...
-        var fail = std.testing.FailingAllocator.init(alloc, 0);
+        var fail = std.testing.FailingAllocator.init(alloc, .{});
         break :fail fail.allocator();
     };
     errdefer if (arena_available and arena_owned) {
diff --git a/src/cli/list_fonts.zig b/src/cli/list_fonts.zig
index eced0f472..df7432634 100644
--- a/src/cli/list_fonts.zig
+++ b/src/cli/list_fonts.zig
@@ -1,3 +1,61 @@
-pub fn run() !u8 {
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const ArenaAllocator = std.heap.ArenaAllocator;
+const args = @import("args.zig");
+const font = @import("../font/main.zig");
+
+const log = std.log.scoped(.list_fonts);
+
+pub const Config = struct {
+    /// This is set by the CLI parser for deinit.
+    _arena: ?ArenaAllocator = null,
+
+    pub fn deinit(self: *Config) void {
+        if (self._arena) |arena| arena.deinit();
+        self.* = undefined;
+    }
+};
+
+pub fn run(alloc: Allocator) !u8 {
+    var iter = try std.process.argsWithAllocator(alloc);
+    defer iter.deinit();
+    return try runArgs(alloc, &iter);
+}
+
+fn runArgs(alloc: Allocator, argsIter: anytype) !u8 {
+    var config: Config = .{};
+    defer config.deinit();
+    try args.parse(Config, alloc, &config, argsIter);
+
+    // Its possible to build Ghostty without font discovery!
+    if (comptime font.Discover == void) {
+        const stderr = std.io.getStdErr().writer();
+        try stderr.print(
+            \\Ghostty was built without a font discovery mechanism. This is a compile-time
+            \\option. Please review how Ghostty was built from source, contact the
+            \\maintainer to enable a font discovery mechanism, and try again.
+        ,
+            .{},
+        );
+        return 1;
+    }
+
+    const stdout = std.io.getStdOut().writer();
+
+    var disco = font.Discover.init();
+    defer disco.deinit();
+
+    // Look up all available fonts
+    var disco_it = try disco.discover(.{});
+    defer disco_it.deinit();
+    while (try disco_it.next()) |face| {
+        var buf: [1024]u8 = undefined;
+        const name = face.name(&buf) catch |err| {
+            log.err("failed to get font name: {}", .{err});
+            continue;
+        };
+        try stdout.print("{s}\n", .{name});
+    }
+
     return 0;
 }