//! Pugz Benchmark - Template Rendering
//!
//! This benchmark parses templates ONCE, then renders 2000 times.
//! This matches how Pug.js benchmark works (compile once, render many).
//!
//! Run: zig build bench

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

const iterations: usize = 2000;
const templates_dir = "src/benchmarks/templates";

// Data structures matching JSON files
const SubFriend = struct {
    id: i64,
    name: []const u8,
};

const Friend = struct {
    name: []const u8,
    balance: []const u8,
    age: i64,
    address: []const u8,
    picture: []const u8,
    company: []const u8,
    email: []const u8,
    emailHref: []const u8,
    about: []const u8,
    tags: []const []const u8,
    friends: []const SubFriend,
};

const Account = struct {
    balance: i64,
    balanceFormatted: []const u8,
    status: []const u8,
    negative: bool,
};

const Project = struct {
    name: []const u8,
    url: []const u8,
    description: []const u8,
};

const SearchRecord = struct {
    imgUrl: []const u8,
    viewItemUrl: []const u8,
    title: []const u8,
    description: []const u8,
    featured: bool,
    sizes: ?[]const []const u8,
};

pub fn main() !void {
    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    defer _ = gpa.deinit();
    const allocator = gpa.allocator();

    std.debug.print("\n", .{});
    std.debug.print("╔═══════════════════════════════════════════════════════════════╗\n", .{});
    std.debug.print("║   Pugz Benchmark ({d} iterations, parse once)                 ║\n", .{iterations});
    std.debug.print("║   Templates: {s}/*.pug                           ║\n", .{templates_dir});
    std.debug.print("╚═══════════════════════════════════════════════════════════════╝\n", .{});

    // Load JSON data
    std.debug.print("\nLoading JSON data and parsing templates...\n", .{});

    var data_arena = std.heap.ArenaAllocator.init(allocator);
    defer data_arena.deinit();
    const data_alloc = data_arena.allocator();

    const simple0 = try loadJson(struct { name: []const u8 }, data_alloc, "simple-0.json");
    const simple1 = try loadJson(struct {
        name: []const u8,
        messageCount: i64,
        colors: []const []const u8,
        primary: bool,
    }, data_alloc, "simple-1.json");
    const simple2 = try loadJson(struct {
        header: []const u8,
        header2: []const u8,
        header3: []const u8,
        header4: []const u8,
        header5: []const u8,
        header6: []const u8,
        list: []const []const u8,
    }, data_alloc, "simple-2.json");
    const if_expr = try loadJson(struct { accounts: []const Account }, data_alloc, "if-expression.json");
    const projects = try loadJson(struct {
        title: []const u8,
        text: []const u8,
        projects: []const Project,
    }, data_alloc, "projects-escaped.json");
    const search = try loadJson(struct { searchRecords: []const SearchRecord }, data_alloc, "search-results.json");
    const friends_data = try loadJson(struct { friends: []const Friend }, data_alloc, "friends.json");

    // Load and PARSE templates ONCE (like Pug.js compiles once)
    const simple0_tpl = try loadTemplate(data_alloc, "simple-0.pug");
    const simple1_tpl = try loadTemplate(data_alloc, "simple-1.pug");
    const simple2_tpl = try loadTemplate(data_alloc, "simple-2.pug");
    const if_expr_tpl = try loadTemplate(data_alloc, "if-expression.pug");
    const projects_tpl = try loadTemplate(data_alloc, "projects-escaped.pug");
    const search_tpl = try loadTemplate(data_alloc, "search-results.pug");
    const friends_tpl = try loadTemplate(data_alloc, "friends.pug");

    // Parse templates once
    const simple0_ast = try pugz.template.parse(data_alloc, simple0_tpl);
    const simple1_ast = try pugz.template.parse(data_alloc, simple1_tpl);
    const simple2_ast = try pugz.template.parse(data_alloc, simple2_tpl);
    const if_expr_ast = try pugz.template.parse(data_alloc, if_expr_tpl);
    const projects_ast = try pugz.template.parse(data_alloc, projects_tpl);
    const search_ast = try pugz.template.parse(data_alloc, search_tpl);
    const friends_ast = try pugz.template.parse(data_alloc, friends_tpl);

    std.debug.print("Loaded. Starting benchmark (render only)...\n\n", .{});

    var total: f64 = 0;

    total += try bench("simple-0", allocator, simple0_ast, simple0);
    total += try bench("simple-1", allocator, simple1_ast, simple1);
    total += try bench("simple-2", allocator, simple2_ast, simple2);
    total += try bench("if-expression", allocator, if_expr_ast, if_expr);
    total += try bench("projects-escaped", allocator, projects_ast, projects);
    total += try bench("search-results", allocator, search_ast, search);
    total += try bench("friends", allocator, friends_ast, friends_data);

    std.debug.print("\n", .{});
    std.debug.print("  {s:<20} => {d:>7.1}ms\n", .{ "TOTAL", total });
    std.debug.print("\n", .{});
}

fn loadJson(comptime T: type, alloc: std.mem.Allocator, comptime filename: []const u8) !T {
    const path = templates_dir ++ "/" ++ filename;
    const content = try std.fs.cwd().readFileAlloc(alloc, path, 10 * 1024 * 1024);
    const parsed = try std.json.parseFromSlice(T, alloc, content, .{});
    return parsed.value;
}

fn loadTemplate(alloc: std.mem.Allocator, comptime filename: []const u8) ![]const u8 {
    const path = templates_dir ++ "/" ++ filename;
    return try std.fs.cwd().readFileAlloc(alloc, path, 1 * 1024 * 1024);
}

fn bench(
    name: []const u8,
    allocator: std.mem.Allocator,
    ast: *pugz.parser.Node,
    data: anytype,
) !f64 {
    var arena = std.heap.ArenaAllocator.init(allocator);
    defer arena.deinit();

    var timer = try std.time.Timer.start();
    for (0..iterations) |_| {
        _ = arena.reset(.retain_capacity);
        _ = pugz.template.renderAst(arena.allocator(), ast, data) catch |err| {
            std.debug.print("  {s:<20} => ERROR: {}\n", .{ name, err });
            return 0;
        };
    }
    const ms = @as(f64, @floatFromInt(timer.read())) / 1_000_000.0;
    std.debug.print("  {s:<20} => {d:>7.1}ms\n", .{ name, ms });
    return ms;
}