//! Every builtin as JSON, for the docs' glossary (docs/typ/builtins-tty.json
//! and builtins-gui.json, a build's list each; style.typ merges them):
//! the rows the `Help` builtin draws (pardes.builtin_rows: the leader path
//! and the other shortcuts) with what /commands says of each word (its doc
//! comment's first sentence, or a setting's doc). One source, so the
//! glossary and Help cannot drift; the test below fails when the committed
//! copy is stale, and `zig build builtins-json` rewrites it.
const std = @import("std");
const pardes = @import("pardes.zig");
const builtins = @import("builtins.zig");
const config = @import("config.zig");
const ctl = @import("ninep/ctl.zig");

fn str(w: *std.Io.Writer, s: []const u8) !void {
    try w.writeByte('"');
    for (s) |c| switch (c) {
        '"' => try w.writeAll("\\\""),
        '\\' => try w.writeAll("\\\\"),
        '\n' => try w.writeAll("\\n"),
        0...9, 11...0x1f => try w.print("\\u{x:0>4}", .{c}),
        else => try w.writeByte(c),
    };
    try w.writeByte('"');
}

const Entry = struct { name: []const u8, row: usize };

fn lessName(_: void, a: Entry, b: Entry) bool {
    return std.mem.lessThan(u8, a.name, b.name);
}

pub fn write(w: *std.Io.Writer) !void {
    var order: [pardes.builtin_rows.len]Entry = undefined;
    for (pardes.builtin_rows, 0..) |row, i| order[i] = .{ .name = @tagName(row.cmd), .row = i };
    std.mem.sort(Entry, &order, {}, lessName);
    try w.writeAll("[\n");
    for (order, 0..) |e, n| {
        const row = pardes.builtin_rows[e.row];
        const b = row.cmd;
        const name = @tagName(b);
        try w.writeAll("  {\"name\": ");
        try str(w, name);
        try w.writeAll(", \"leader\": ");
        if (row.path) |p| {
            try w.writeAll("\"SPC");
            for (p) |c| try w.print(" {c}", .{c});
            try w.writeByte('"');
        } else try w.writeAll("null");
        // Help's line ends in the other shortcuts, after the name's column.
        try w.writeAll(", \"also\": [");
        const at = std.mem.indexOf(u8, row.line, name).? + name.len;
        const rest = std.mem.trim(u8, row.line[at..], " ");
        var parts = std.mem.splitSequence(u8, rest, ", ");
        var first = true;
        while (parts.next()) |part| if (part.len > 0) {
            if (!first) try w.writeAll(", ");
            first = false;
            try str(w, part);
        };
        try w.writeAll("], \"arg\": ");
        try w.writeAll(if (builtins.registry.takesArg(b)) "true" else "false");
        try w.writeAll(", \"scope\": ");
        try str(w, if (b == .Edit) "both" else if (builtins.registry.scope(b) == .session) "root" else "pane");
        const setting = config.Runtime.find(name);
        try w.writeAll(", \"setting\": ");
        try w.writeAll(if (setting != null) "true" else "false");
        try w.writeAll(", \"choices\": ");
        if (setting) |s| if (config.Runtime.choices(s.action)) |v| try str(w, v) else try w.writeAll("null") else try w.writeAll("null");
        var buf: [2048]u8 = undefined;
        const doc = if (setting) |s| s.doc else ctl.summaryOf(name, &buf);
        try w.writeAll(", \"doc\": ");
        try str(w, doc);
        try w.writeAll(if (n + 1 < order.len) "},\n" else "}\n");
    }
    try w.writeAll("]\n");
}

test "docs/typ/builtins-<platform>.json is what the registry says now" {
    // a terminal build checks its file, a window build its own
    const file = switch (pardes.platform) {
        .tty => "builtins-tty.json",
        .gui => "builtins-gui.json",
        else => return error.SkipZigTest,
    };
    const gpa = std.testing.allocator;
    var out: std.Io.Writer.Allocating = .init(gpa);
    defer out.deinit();
    try write(&out.writer);
    var dir = try std.Io.Dir.cwd().openDir(std.testing.io, @import("doc_typ").dir, .{});
    defer dir.close(std.testing.io);
    const committed = try dir.readFileAlloc(std.testing.io, file, gpa, .limited(1 << 20));
    defer gpa.free(committed);
    if (!std.mem.eql(u8, committed, out.written())) {
        std.debug.print("docs/typ/{s} is stale: run `zig build builtins-json -Dplatform={s} --prefix <dir>`\n", .{ file, @tagName(pardes.platform) });
        return error.StaleBuiltinsJson;
    }
}