From 15af4a8387c0236da36575ac14c90a7c267ca8ea Mon Sep 17 00:00:00 2001
From: Marto <marto@marto.si>
Date: Sun, 9 Feb 2025 19:31:27 +0100
Subject: [PATCH] initial commit

---
 build.zig       | 91 +++++++++++++++++++++++++++++++++++++++++++++++++
 build.zig.zon   | 72 ++++++++++++++++++++++++++++++++++++++
 src/file_op.zig | 66 +++++++++++++++++++++++++++++++++++
 src/main.zig    | 60 ++++++++++++++++++++++++++++++++
 4 files changed, 289 insertions(+)
 create mode 100644 build.zig
 create mode 100644 build.zig.zon
 create mode 100644 src/file_op.zig
 create mode 100644 src/main.zig

diff --git a/build.zig b/build.zig
new file mode 100644
index 0000000..ae53d19
--- /dev/null
+++ b/build.zig
@@ -0,0 +1,91 @@
+const std = @import("std");
+
+// Although this function looks imperative, note that its job is to
+// declaratively construct a build graph that will be executed by an external
+// runner.
+pub fn build(b: *std.Build) void {
+    // Standard target options allows the person running `zig build` to choose
+    // what target to build for. Here we do not override the defaults, which
+    // means any target is allowed, and the default is native. Other options
+    // for restricting supported target set are available.
+    const target = b.standardTargetOptions(.{});
+
+    // Standard optimization options allow the person running `zig build` to select
+    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
+    // set a preferred release mode, allowing the user to decide how to optimize.
+    const optimize = b.standardOptimizeOption(.{});
+
+    // const lib = b.addStaticLibrary(.{
+    //     .name = "todo",
+    //     // In this case the main source file is merely a path, however, in more
+    //     // complicated build scripts, this could be a generated file.
+    //     .root_source_file = b.path("src/root.zig"),
+    //     .target = target,
+    //     .optimize = optimize,
+    // });
+
+    // This declares intent for the library to be installed into the standard
+    // location when the user invokes the "install" step (the default step when
+    // running `zig build`).
+    // b.installArtifact(lib);
+
+    const exe = b.addExecutable(.{
+        .name = "todo",
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    // This declares intent for the executable to be installed into the
+    // standard location when the user invokes the "install" step (the default
+    // step when running `zig build`).
+    b.installArtifact(exe);
+
+    // This *creates* a Run step in the build graph, to be executed when another
+    // step is evaluated that depends on it. The next line below will establish
+    // such a dependency.
+    const run_cmd = b.addRunArtifact(exe);
+
+    // By making the run step depend on the install step, it will be run from the
+    // installation directory rather than directly from within the cache directory.
+    // This is not necessary, however, if the application depends on other installed
+    // files, this ensures they will be present and in the expected location.
+    run_cmd.step.dependOn(b.getInstallStep());
+
+    // This allows the user to pass arguments to the application in the build
+    // command itself, like this: `zig build run -- arg1 arg2 etc`
+    if (b.args) |args| {
+        run_cmd.addArgs(args);
+    }
+
+    // This creates a build step. It will be visible in the `zig build --help` menu,
+    // and can be selected like this: `zig build run`
+    // This will evaluate the `run` step rather than the default, which is "install".
+    const run_step = b.step("run", "Run the app");
+    run_step.dependOn(&run_cmd.step);
+
+    // Creates a step for unit testing. This only builds the test executable
+    // but does not run it.
+    // const lib_unit_tests = b.addTest(.{
+    //     .root_source_file = b.path("src/root.zig"),
+    //     .target = target,
+    //     .optimize = optimize,
+    // });
+
+    // const run_lib_unit_tests = b.addRunArtifact(lib_unit_tests);
+
+    const exe_unit_tests = b.addTest(.{
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
+
+    // Similar to creating the run step earlier, this exposes a `test` step to
+    // the `zig build --help` menu, providing a way for the user to request
+    // running the unit tests.
+    const test_step = b.step("test", "Run unit tests");
+    // test_step.dependOn(&run_lib_unit_tests.step);
+    test_step.dependOn(&run_exe_unit_tests.step);
+}
diff --git a/build.zig.zon b/build.zig.zon
new file mode 100644
index 0000000..d834152
--- /dev/null
+++ b/build.zig.zon
@@ -0,0 +1,72 @@
+.{
+    // This is the default name used by packages depending on this one. For
+    // example, when a user runs `zig fetch --save <url>`, this field is used
+    // as the key in the `dependencies` table. Although the user can choose a
+    // different name, most users will stick with this provided value.
+    //
+    // It is redundant to include "zig" in this name because it is already
+    // within the Zig package namespace.
+    .name = "todo",
+
+    // This is a [Semantic Version](https://semver.org/).
+    // In a future version of Zig it will be used for package deduplication.
+    .version = "0.0.0",
+
+    // This field is optional.
+    // This is currently advisory only; Zig does not yet do anything
+    // with this value.
+    //.minimum_zig_version = "0.11.0",
+
+    // This field is optional.
+    // Each dependency must either provide a `url` and `hash`, or a `path`.
+    // `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
+    // Once all dependencies are fetched, `zig build` no longer requires
+    // internet connectivity.
+    .dependencies = .{
+        // See `zig fetch --save <url>` for a command-line interface for adding dependencies.
+        //.example = .{
+        //    // When updating this field to a new URL, be sure to delete the corresponding
+        //    // `hash`, otherwise you are communicating that you expect to find the old hash at
+        //    // the new URL.
+        //    .url = "https://example.com/foo.tar.gz",
+        //
+        //    // This is computed from the file contents of the directory of files that is
+        //    // obtained after fetching `url` and applying the inclusion rules given by
+        //    // `paths`.
+        //    //
+        //    // This field is the source of truth; packages do not come from a `url`; they
+        //    // come from a `hash`. `url` is just one of many possible mirrors for how to
+        //    // obtain a package matching this `hash`.
+        //    //
+        //    // Uses the [multihash](https://multiformats.io/multihash/) format.
+        //    .hash = "...",
+        //
+        //    // When this is provided, the package is found in a directory relative to the
+        //    // build root. In this case the package's hash is irrelevant and therefore not
+        //    // computed. This field and `url` are mutually exclusive.
+        //    .path = "foo",
+
+        //    // When this is set to `true`, a package is declared to be lazily
+        //    // fetched. This makes the dependency only get fetched if it is
+        //    // actually used.
+        //    .lazy = false,
+        //},
+    },
+
+    // Specifies the set of files and directories that are included in this package.
+    // Only files and directories listed here are included in the `hash` that
+    // is computed for this package. Only files listed here will remain on disk
+    // when using the zig package manager. As a rule of thumb, one should list
+    // files required for compilation plus any license(s).
+    // Paths are relative to the build root. Use the empty string (`""`) to refer to
+    // the build root itself.
+    // A directory listed here means that all files within, recursively, are included.
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+        "src",
+        // For example...
+        //"LICENSE",
+        //"README.md",
+    },
+}
diff --git a/src/file_op.zig b/src/file_op.zig
new file mode 100644
index 0000000..096783e
--- /dev/null
+++ b/src/file_op.zig
@@ -0,0 +1,66 @@
+const std = @import("std");
+const fs = std.fs;
+
+const FileRead = struct {
+    file: fs.File,
+    tasks: std.ArrayList([]u8),
+};
+
+pub fn readTasksFromFile(allocator: std.mem.Allocator, filename: []const u8) !FileRead {
+    var tasks = std.ArrayList([]u8).init(allocator);
+
+    var file = fs.cwd().openFile(filename, .{ .mode = .read_write }) catch |err| {
+        if (err == error.FileNotFound) {
+            std.debug.print("File not found: {s}\n", .{filename});
+            // todo needs to be closed eventually
+            const new_file = fs.cwd().createFile(filename, .{}) catch |e| {
+                std.debug.print("Failed to create the file: {}", .{e});
+                return e;
+            };
+
+            return FileRead{
+                .file = new_file,
+                .tasks = tasks,
+            };
+        } else {
+            std.debug.print("Failed to open the file: {s}, error: {}\n", .{ filename, err });
+            return err;
+        }
+    };
+
+    // wrap the file reader in a buffered reader
+    // since it's usually faster to read a bunch of bytes at once.
+    var buf_reader = std.io.bufferedReader(file.reader());
+    const reader = buf_reader.reader();
+
+    var line = std.ArrayList(u8).init(allocator);
+    defer line.deinit();
+
+    const writer = line.writer();
+
+    while (reader.streamUntilDelimiter(writer, '\n', null)) {
+        // clear the line so we can reuse it
+        defer line.clearRetainingCapacity();
+
+        const copy = try allocator.dupe(u8, line.items);
+        try tasks.append(copy);
+    } else |err| switch (err) {
+        error.EndOfStream => {
+            // end of file
+            if (line.items.len > 0) {
+                const copy = try allocator.dupe(u8, line.items);
+                try tasks.append(copy);
+            }
+        },
+        else => return err, //propagate error
+    }
+
+    return FileRead{ .file = file, .tasks = tasks };
+}
+
+pub fn writeTasksToFile(file_system: FileRead) !void {
+    for (file_system.tasks.items) |item| {
+        try file_system.file.writeAll(item);
+        try file_system.file.writeAll("\n");
+    }
+}
diff --git a/src/main.zig b/src/main.zig
new file mode 100644
index 0000000..084342c
--- /dev/null
+++ b/src/main.zig
@@ -0,0 +1,60 @@
+const std = @import("std");
+const file_op = @import("file_op.zig");
+
+pub fn main() !void {
+    const filename = "todo-db.txt";
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    defer _ = gpa.deinit();
+    const allocator = gpa.allocator();
+
+    var file_res = file_op.readTasksFromFile(allocator, filename) catch |err| {
+        std.debug.print("Failed read or create file, exiting ...", .{});
+        return err;
+    };
+
+    defer {
+        for (file_res.tasks.items) |task| {
+            allocator.free(task);
+        }
+        file_res.tasks.deinit();
+        file_res.file.close();
+    }
+
+    std.debug.print("Reading from file:\n", .{});
+    for (file_res.tasks.items) |i| {
+        std.debug.print("{s}\n", .{i});
+    }
+
+    try userInteraction();
+
+    file_op.writeTasksToFile(file_res) catch |err| {
+        std.debug.print("Error while writing data to file:\n{}", .{err});
+    };
+}
+
+fn userInteraction() !void {
+    const stdin = std.io.getStdIn().reader();
+    const stdout = std.io.getStdOut().writer();
+    // var buf: [100]u8 = undefined;
+
+    while (true) {
+        try stdout.print("Please enter your choice add/remove/edit/quit: ", .{});
+        const bare_line = try stdin.readUntilDelimiterAlloc(std.heap.page_allocator, '\n', 8192);
+        defer std.heap.page_allocator.free(bare_line);
+        // windows legacy
+        const line = std.mem.trim(u8, bare_line, "\r");
+        std.debug.print("You entered: {s}\n", .{line});
+
+        const Case = enum { add, edit, delete, quit };
+        const case = std.meta.stringToEnum(Case, line) orelse return;
+
+        switch (case) {
+            .add => {},
+            .edit => {},
+            .delete => {},
+            .quit => break,
+        }
+
+        //break;
+    }
+}