// SPDX-FileCopyrightText: © 2026 Jeffrey C. Ollie <jeff@ocjtech.us>
// SPDX-License-Identifier: MIT

const std = @import("std");
const zine = @import("zine");

pub fn build(b: *std.Build) !void {
    // libghostty-vt is built by Nix from Ghostty's own source tree (see
    // ghostty-vt-wasm.nix) and handed over as a path. The devshell exports
    // both values.
    const vt_wasm = b.option(
        []const u8,
        "vt-wasm",
        "Path to ghostty-vt.wasm (the devshell exports it as $VT_WASM)",
    ) orelse {
        std.log.err("-Dvt-wasm=PATH is required; in the devshell use -Dvt-wasm=\"$VT_WASM\"", .{});
        return error.MissingVtWasm;
    };
    // Mermaid, which draws the diagrams, comes from its npm package by way of
    // Nix (see mermaid.nix); the devshell exports it too.
    const mermaid = b.option(
        []const u8,
        "mermaid",
        "Path to mermaid.min.js (the devshell exports it as $MERMAID_JS)",
    ) orelse {
        std.log.err("-Dmermaid=PATH is required; in the devshell use -Dmermaid=\"$MERMAID_JS\"", .{});
        return error.MissingMermaid;
    };
    const ghostty_revision = b.option(
        []const u8,
        "ghostty-revision",
        "The Ghostty commit the wasm was built from (the devshell exports it as $GHOSTTY_REVISION)",
    ) orelse "unknown";

    // A module the pages import to say which Ghostty they ran against.
    const build_info = b.addWriteFiles().add(
        "build-info.js",
        b.fmt("export const ghosttyRevision = \"{f}\";\n", .{std.zig.fmtString(ghostty_revision)}),
    );

    const build_assets: []const zine.BuildAsset = &.{
        .{
            .name = "ghostty-vt.wasm",
            .install_path = "ghostty-vt.wasm",
            .install_always = true,
            .lp = .{ .cwd_relative = vt_wasm },
        },
        .{
            .name = "mermaid.min.js",
            .install_path = "mermaid.min.js",
            .install_always = true,
            .lp = .{ .cwd_relative = mermaid },
        },
        .{
            .name = "build-info.js",
            .install_path = "build-info.js",
            .install_always = true,
            .lp = build_info,
        },
    };

    const options: zine.Options = .{
        .website_root = b.path("website"),
        .output_path = "public",
        .build_assets = build_assets,
    };

    const release = b.step("release", "Build the website into zig-out/public");
    const website = zine.website(b, options);
    for (build_assets) |asset| website.addFileInput(asset.lp);
    release.dependOn(&website.step);

    // A Markdown copy of every page, and llms.txt indexing them, made from
    // the same sources. Zine refuses to write into a directory that is not
    // empty, so these are made apart and installed beside its output only
    // once it has finished.
    const markdown = b.addSystemCommand(&.{"node"});
    markdown.addFileArg(b.path("tools/markdown.mjs"));
    markdown.addDirectoryArg(b.path("website"));
    const markdown_out = markdown.addOutputDirectoryArg("markdown");
    // It reads every page's source, which the build cannot list for it.
    markdown.has_side_effects = true;
    const install_markdown = b.addInstallDirectory(.{
        .source_dir = markdown_out,
        .install_dir = .prefix,
        .install_subdir = "public",
    });
    install_markdown.step.dependOn(&website.step);
    release.dependOn(&install_markdown.step);

    const serve = b.step("serve", "Start the Zine development server");
    serve.dependOn(&zine.serve(b, options).step);
}