From 602a4dff01cf505533f8de8307c3781ea947f2aa Mon Sep 17 00:00:00 2001
From: CJ van den Berg <cj@vdbonline.com>
Date: Thu, 21 Mar 2024 22:52:44 +0100
Subject: [PATCH] feat: WIP add project manager service

The project manager service will provide fuzzy find, LRU, and similar
background services for open projects.
---
 build.zig                    |  11 ++
 src/project_manager.zig      | 296 +++++++++++++++++++++++++++++++++++
 src/service_template.zig     |  78 +++++++++
 src/tui/mainview.zig         |   9 ++
 src/tui/status/filestate.zig |  10 +-
 5 files changed, 400 insertions(+), 4 deletions(-)
 create mode 100644 src/project_manager.zig
 create mode 100644 src/service_template.zig

diff --git a/build.zig b/build.zig
index 76311e8..161a2d2 100644
--- a/build.zig
+++ b/build.zig
@@ -137,6 +137,16 @@ pub fn build(b: *std.Build) void {
         },
     });
 
+    const project_manager_mod = b.createModule(.{
+        .root_source_file = .{ .path = "src/project_manager.zig" },
+        .imports = &.{
+            .{ .name = "log", .module = log_mod },
+            .{ .name = "cbor", .module = cbor_mod },
+            .{ .name = "thespian", .module = thespian_mod },
+            .{ .name = "tracy", .module = tracy_mod },
+        },
+    });
+
     const diff_mod = b.createModule(.{
         .root_source_file = .{ .path = "src/diff.zig" },
         .imports = &.{
@@ -163,6 +173,7 @@ pub fn build(b: *std.Build) void {
             .{ .name = "config", .module = config_mod },
             .{ .name = "log", .module = log_mod },
             .{ .name = "location_history", .module = location_history_mod },
+            .{ .name = "project_manager", .module = project_manager_mod },
             .{ .name = "syntax", .module = syntax_dep.module("syntax") },
             .{ .name = "text_manip", .module = text_manip_mod },
             .{ .name = "Buffer", .module = Buffer_mod },
diff --git a/src/project_manager.zig b/src/project_manager.zig
new file mode 100644
index 0000000..b1d0080
--- /dev/null
+++ b/src/project_manager.zig
@@ -0,0 +1,296 @@
+const std = @import("std");
+const tp = @import("thespian");
+const cbor = @import("cbor");
+const log = @import("log");
+const tracy = @import("tracy");
+
+pid: ?tp.pid,
+
+const Self = @This();
+const module_name = @typeName(Self);
+pub const Error = error{ OutOfMemory, Exit };
+
+pub fn create(a: std.mem.Allocator) Error!Self {
+    return .{ .pid = try Process.create(a) };
+}
+
+pub fn from_pid(pid: tp.pid_ref) Error!Self {
+    return .{ .pid = pid.clone() };
+}
+
+pub fn deinit(self: *Self) void {
+    if (self.pid) |pid| {
+        self.pid = null;
+        pid.deinit();
+    }
+}
+
+pub fn shutdown(self: *Self) void {
+    if (self.pid) |pid| {
+        pid.send(.{"shutdown"}) catch {};
+        self.deinit();
+    }
+}
+
+pub fn open(self: *const Self, project_directory: []const u8) tp.result {
+    const pid = if (self.pid) |pid| pid else return tp.exit_error(error.Shutdown);
+    try pid.send(.{ "open", project_directory });
+}
+
+const Process = struct {
+    a: std.mem.Allocator,
+    parent: tp.pid,
+    logger: log.Logger,
+    receiver: Receiver,
+    projects: ProjectsMap,
+
+    const Receiver = tp.Receiver(*Process);
+    const ProjectsMap = std.StringHashMap(*Project);
+
+    pub fn create(a: std.mem.Allocator) Error!tp.pid {
+        const self = try a.create(Process);
+        self.* = .{
+            .a = a,
+            .parent = tp.self_pid().clone(),
+            .logger = log.logger(module_name),
+            .receiver = Receiver.init(Process.receive, self),
+            .projects = ProjectsMap.init(a),
+        };
+        return tp.spawn_link(self.a, self, Process.start, module_name) catch |e| tp.exit_error(e);
+    }
+
+    fn deinit(self: *Process) void {
+        var i = self.projects.iterator();
+        while (i.next()) |p| {
+            self.a.free(p.key_ptr.*);
+            p.value_ptr.*.deinit();
+            self.a.destroy(p.value_ptr.*);
+        }
+        self.projects.deinit();
+        self.parent.deinit();
+        self.a.destroy(self);
+    }
+
+    fn start(self: *Process) tp.result {
+        _ = tp.set_trap(true);
+        tp.receive(&self.receiver);
+    }
+
+    fn receive(self: *Process, from: tp.pid_ref, m: tp.message) tp.result {
+        errdefer self.deinit();
+        var project_directory: []const u8 = undefined;
+        var path: []const u8 = undefined;
+
+        if (try m.match(.{ "walk_tree_entry", tp.extract(&project_directory), tp.extract(&path) })) {
+            if (self.projects.get(project_directory)) |project|
+                project.add_file(path) catch |e| self.logger.err("walk_tree_entry", e);
+            // self.logger.print("file: {s}", .{path});
+        } else if (try m.match(.{ "walk_tree_done", tp.extract(&project_directory) })) {
+            const project = self.projects.get(project_directory) orelse return;
+            self.logger.print("opened: {s} with {d} files in {d} ms", .{
+                project_directory,
+                project.files.count(),
+                std.time.milliTimestamp() - project.open_time,
+            });
+        } else if (try m.match(.{ "open", tp.extract(&project_directory) })) {
+            self.open(project_directory) catch |e| return from.send_raw(tp.exit_message(e));
+        } else if (try m.match(.{"shutdown"})) {
+            return tp.exit_normal();
+        } else if (try m.match(.{ "exit", "normal" })) {
+            return;
+        } else {
+            self.logger.err("receive", tp.unexpected(m));
+        }
+    }
+
+    fn open(self: *Process, project_directory: []const u8) error{ OutOfMemory, Exit }!void {
+        self.logger.print("opening: {s}", .{project_directory});
+        if (self.projects.get(project_directory) == null) {
+            const project = try self.a.create(Project);
+            project.* = try Project.init(self.a, project_directory);
+            try self.projects.put(try self.a.dupe(u8, project_directory), project);
+            try walk_tree_async(self.a, project_directory);
+        }
+    }
+};
+
+const Project = struct {
+    a: std.mem.Allocator,
+    name: []const u8,
+    files: FilesMap,
+    open_time: i64,
+
+    const FilesMap = std.StringHashMap(void);
+
+    fn init(a: std.mem.Allocator, name: []const u8) error{OutOfMemory}!Project {
+        return .{
+            .a = a,
+            .name = try a.dupe(u8, name),
+            .files = FilesMap.init(a),
+            .open_time = std.time.milliTimestamp(),
+        };
+    }
+
+    fn deinit(self: *Project) void {
+        var i = self.files.iterator();
+        while (i.next()) |p| self.a.free(p.key_ptr.*);
+        self.files.deinit();
+        self.a.free(self.name);
+    }
+
+    fn add_file(self: *Project, path: []const u8) error{OutOfMemory}!void {
+        if (self.files.get(path) != null) return;
+        try self.files.put(try self.a.dupe(u8, path), {});
+    }
+};
+
+fn walk_tree_async(a_: std.mem.Allocator, root_path_: []const u8) tp.result {
+    return struct {
+        a: std.mem.Allocator,
+        root_path: []const u8,
+        parent: tp.pid,
+
+        const tree_walker = @This();
+
+        fn spawn_link(a: std.mem.Allocator, root_path: []const u8) tp.result {
+            const self = a.create(tree_walker) catch |e| return tp.exit_error(e);
+            self.* = tree_walker.init(a, root_path) catch |e| return tp.exit_error(e);
+            const pid = tp.spawn_link(a, self, tree_walker.start, module_name ++ ".tree_walker") catch |e| return tp.exit_error(e);
+            pid.deinit();
+        }
+
+        fn init(a: std.mem.Allocator, root_path: []const u8) error{OutOfMemory}!tree_walker {
+            return .{
+                .a = a,
+                .root_path = try a.dupe(u8, root_path),
+                .parent = tp.self_pid().clone(),
+            };
+        }
+
+        fn start(self: *tree_walker) tp.result {
+            self.walk() catch |e| return tp.exit_error(e);
+            return tp.exit_normal();
+        }
+
+        fn deinit(self: *tree_walker) void {
+            self.a.free(self.root_path);
+            self.parent.deinit();
+        }
+
+        fn walk(self: *tree_walker) !void {
+            const frame = tracy.initZone(@src(), .{ .name = "project scan" });
+            defer frame.deinit();
+            defer {
+                self.parent.send(.{ "walk_tree_done", self.root_path }) catch {};
+                self.deinit();
+            }
+            var dir = try std.fs.cwd().openDir(self.root_path, .{ .iterate = true });
+            defer dir.close();
+
+            var walker = try walk_filtered(dir, self.a);
+            defer walker.deinit();
+
+            while (try walker.next()) |path|
+                try self.parent.send(.{ "walk_tree_entry", self.root_path, path });
+        }
+    }.spawn_link(a_, root_path_);
+}
+
+const filtered_dirs = [_][]const u8{ ".git", ".cache", "zig-out", "zig-cache" };
+
+fn is_filtered_dir(dirname: []const u8) bool {
+    for (filtered_dirs) |filter|
+        if (std.mem.eql(u8, filter, dirname))
+            return true;
+    return false;
+}
+
+const FilteredWalker = struct {
+    stack: std.ArrayList(StackItem),
+    name_buffer: std.ArrayList(u8),
+
+    const Path = []const u8;
+
+    const StackItem = struct {
+        iter: std.fs.Dir.Iterator,
+        dirname_len: usize,
+    };
+
+    pub fn next(self: *FilteredWalker) error{OutOfMemory}!?Path {
+        while (self.stack.items.len != 0) {
+            var top = &self.stack.items[self.stack.items.len - 1];
+            var containing = top;
+            var dirname_len = top.dirname_len;
+            if (top.iter.next() catch {
+                var item = self.stack.pop();
+                if (self.stack.items.len != 0) {
+                    item.iter.dir.close();
+                }
+                continue;
+            }) |base| {
+                self.name_buffer.shrinkRetainingCapacity(dirname_len);
+                if (self.name_buffer.items.len != 0) {
+                    try self.name_buffer.append(std.fs.path.sep);
+                    dirname_len += 1;
+                }
+                try self.name_buffer.appendSlice(base.name);
+                switch (base.kind) {
+                    .directory => {
+                        if (is_filtered_dir(base.name))
+                            continue;
+                        var new_dir = top.iter.dir.openDir(base.name, .{ .iterate = true }) catch |err| switch (err) {
+                            error.NameTooLong => unreachable, // no path sep in base.name
+                            else => continue,
+                        };
+                        {
+                            errdefer new_dir.close();
+                            try self.stack.append(StackItem{
+                                .iter = new_dir.iterateAssumeFirstIteration(),
+                                .dirname_len = self.name_buffer.items.len,
+                            });
+                            top = &self.stack.items[self.stack.items.len - 1];
+                            containing = &self.stack.items[self.stack.items.len - 2];
+                        }
+                    },
+                    .file => return self.name_buffer.items,
+                    else => continue,
+                }
+            } else {
+                var item = self.stack.pop();
+                if (self.stack.items.len != 0) {
+                    item.iter.dir.close();
+                }
+            }
+        }
+        return null;
+    }
+
+    pub fn deinit(self: *FilteredWalker) void {
+        // Close any remaining directories except the initial one (which is always at index 0)
+        if (self.stack.items.len > 1) {
+            for (self.stack.items[1..]) |*item| {
+                item.iter.dir.close();
+            }
+        }
+        self.stack.deinit();
+        self.name_buffer.deinit();
+    }
+};
+
+fn walk_filtered(dir: std.fs.Dir, allocator: std.mem.Allocator) !FilteredWalker {
+    var name_buffer = std.ArrayList(u8).init(allocator);
+    errdefer name_buffer.deinit();
+
+    var stack = std.ArrayList(FilteredWalker.StackItem).init(allocator);
+    errdefer stack.deinit();
+
+    try stack.append(FilteredWalker.StackItem{
+        .iter = dir.iterate(),
+        .dirname_len = 0,
+    });
+
+    return FilteredWalker{
+        .stack = stack,
+        .name_buffer = name_buffer,
+    };
+}
diff --git a/src/service_template.zig b/src/service_template.zig
new file mode 100644
index 0000000..8cdff0d
--- /dev/null
+++ b/src/service_template.zig
@@ -0,0 +1,78 @@
+const std = @import("std");
+const tp = @import("thespian");
+const cbor = @import("cbor");
+const log = @import("log");
+
+pid: ?tp.pid,
+
+const Self = @This();
+const module_name = @typeName(Self);
+pub const Error = error{ OutOfMemory, Exit };
+
+pub fn create(a: std.mem.Allocator) Error!Self {
+    return .{ .pid = try Process.create(a) };
+}
+
+pub fn from_pid(pid: tp.pid_ref) Error!Self {
+    return .{ .pid = pid.clone() };
+}
+
+pub fn deinit(self: *Self) void {
+    if (self.pid) |pid| {
+        self.pid = null;
+        pid.deinit();
+    }
+}
+
+pub fn shutdown(self: *Self) void {
+    if (self.pid) |pid| {
+        pid.send(.{"shutdown"}) catch {};
+        self.deinit();
+    }
+}
+
+// pub fn send(self: *Self, m: tp.message) tp.result {
+//     const pid = if (self.pid) |pid| pid else return tp.exit_error(error.Shutdown);
+//     try pid.send(m);
+// }
+
+const Process = struct {
+    a: std.mem.Allocator,
+    parent: tp.pid,
+    logger: log.Logger,
+    receiver: Receiver,
+
+    const Receiver = tp.Receiver(*Process);
+
+    pub fn create(a: std.mem.Allocator) Error!tp.pid {
+        const self = try a.create(Process);
+        self.* = .{
+            .a = a,
+            .parent = tp.self_pid().clone(),
+            .logger = log.logger(module_name),
+            .receiver = Receiver.init(Process.receive, self),
+        };
+        return tp.spawn_link(self.a, self, Process.start) catch |e| tp.exit_error(e);
+    }
+
+    fn deinit(self: *Process) void {
+        self.parent.deinit();
+        self.a.destroy(self);
+    }
+
+    fn start(self: *Process) tp.result {
+        _ = tp.set_trap(true);
+        tp.receive(&self.receiver);
+    }
+
+    fn receive(self: *Process, _: tp.pid_ref, m: tp.message) tp.result {
+        errdefer self.deinit();
+
+        if (try m.match(.{"shutdown"})) {
+            return tp.exit_normal();
+        } else {
+            self.logger.err("receive", tp.unexpected(m));
+            return tp.unexpected(m);
+        }
+    }
+};
diff --git a/src/tui/mainview.zig b/src/tui/mainview.zig
index 920f537..ab91f9c 100644
--- a/src/tui/mainview.zig
+++ b/src/tui/mainview.zig
@@ -4,6 +4,7 @@ const tp = @import("thespian");
 const tracy = @import("tracy");
 const root = @import("root");
 const location_history = @import("location_history");
+const project_manager = @import("project_manager");
 
 const tui = @import("tui.zig");
 const command = @import("command.zig");
@@ -31,6 +32,7 @@ last_match_text: ?[]const u8 = null,
 logview_enabled: bool = false,
 
 location_history: location_history,
+project_manager: project_manager,
 
 const NavState = struct {
     time: i64 = 0,
@@ -42,6 +44,12 @@ const NavState = struct {
 };
 
 pub fn create(a: std.mem.Allocator, n: nc.Plane) !Widget {
+    const project_manager_ = try project_manager.create(a);
+    tp.env.get().proc_set("project", project_manager_.pid.?.ref());
+    var project_name_buf: [std.fs.MAX_PATH_BYTES]u8 = undefined;
+    const project_name = std.fs.cwd().realpath(".", &project_name_buf) catch "(none)";
+    tp.env.get().str_set("project", project_name);
+    // try project_manager_.open(project_name);
     const self = try a.create(Self);
     self.* = .{
         .a = a,
@@ -51,6 +59,7 @@ pub fn create(a: std.mem.Allocator, n: nc.Plane) !Widget {
         .floating_views = WidgetStack.init(a),
         .statusbar = undefined,
         .location_history = try location_history.create(),
+        .project_manager = project_manager_,
     };
     try self.commands.init(self);
     const w = Widget.to(self);
diff --git a/src/tui/status/filestate.zig b/src/tui/status/filestate.zig
index fbd6967..7c22f74 100644
--- a/src/tui/status/filestate.zig
+++ b/src/tui/status/filestate.zig
@@ -33,7 +33,7 @@ const Self = @This();
 pub fn create(a: Allocator, parent: nc.Plane) !Widget {
     const self: *Self = try a.create(Self);
     self.* = try init(a, parent);
-    self.show_cwd();
+    self.show_project();
     return Widget.to(self);
 }
 
@@ -171,7 +171,7 @@ pub fn receive(self: *Self, _: tp.pid_ref, m: tp.message) error{Exit}!bool {
         self.line = 0;
         self.column = 0;
         self.file_exists = true;
-        self.show_cwd();
+        self.show_project();
     }
     if (try m.match(.{ "B", nc.event_type.PRESS, nc.key.BUTTON1, tp.any, tp.any, tp.any, tp.any, tp.any })) {
         self.detailed = !self.detailed;
@@ -192,10 +192,12 @@ fn render_file_icon(self: *Self, _: *const Widget.Theme) void {
     self.plane.cursor_move_rel(0, 1) catch {};
 }
 
-fn show_cwd(self: *Self) void {
+fn show_project(self: *Self) void {
     self.file_icon = "";
     self.file_color = 0x000001;
-    self.name = std.fs.cwd().realpath(".", &self.name_buf) catch "(none)";
+    const project_name = tp.env.get().str("project");
+    @memcpy(self.name_buf[0..project_name.len], project_name);
+    self.name = self.name_buf[0..project_name.len];
     self.abbrv_home();
 }