const std = @import("std");
const pages = @import("pages.zig").pages;

pub fn main(init: std.process.Init) !void {
    const sources_dir = try std.Io.Dir.cwd().createDirPathOpen(init.io, "src", .{});
    defer sources_dir.close(init.io);
    const out_dir = try std.Io.Dir.cwd().createDirPathOpen(init.io, "html-out", .{});
    defer out_dir.close(init.io);

    const templates_dir = try sources_dir.createDirPathOpen(init.io, "templates", .{ .open_options = .{ .iterate = true } });
    defer templates_dir.close(init.io);
    const pages_dir = try sources_dir.createDirPathOpen(init.io, "pages", .{ .open_options = .{ .iterate = true } });
    defer pages_dir.close(init.io);
    try generateHtmlPages(init.io, init.arena.allocator(), templates_dir, pages_dir, out_dir);

    const static_dir = try sources_dir.createDirPathOpen(init.io, "static", .{ .open_options = .{ .iterate = true } });
    defer static_dir.close(init.io);
    try copyStaticFiles(init.io, init.arena.allocator(), static_dir, out_dir);
}

fn generateHtmlPages(io: std.Io, ally: std.mem.Allocator, templates_dir: std.Io.Dir, pages_dir: std.Io.Dir, out_dir: std.Io.Dir) !void {
    for (pages) |page_def| {
        const template = try templates_dir.openFile(io, page_def.template_path, .{});
        defer template.close(io);
        const template_buf = try ally.alloc(u8, (try template.stat(io)).size);
        _ = try template.readPositionalAll(io, template_buf, 0);

        const page = try pages_dir.openFile(io, page_def.source_path, .{});
        defer page.close(io);
        const page_buf = try ally.alloc(u8, (try page.stat(io)).size);
        _ = try page.readPositionalAll(io, page_buf, 0);

        var out_buf: []u8 = template_buf;
        for (page_def.replacements) |replacement| {
            switch (replacement.replacement) {
                .file_content => {
                    out_buf = try std.mem.replaceOwned(u8, ally, out_buf, replacement.placeholder, page_buf);
                },
                .literal => |value| {
                    out_buf = try std.mem.replaceOwned(u8, ally, out_buf, replacement.placeholder, value);
                },
            }
        }

        const maybeDirname = std.mem.cutLast(u8, page_def.source_path, "/");
        if (maybeDirname) |dirname| {
            try out_dir.createDirPath(io, dirname[0]);
        }
        const out = try out_dir.createFile(io, page_def.source_path, .{});
        defer out.close(io);
        std.debug.print("Writing page {s}...\n", .{page_def.source_path});
        try out.writeStreamingAll(io, out_buf);
    }
}

fn copyStaticFiles(io: std.Io, ally: std.mem.Allocator, sources_dir: std.Io.Dir, out_dir: std.Io.Dir) !void {
    var walker = try sources_dir.walk(ally);
    defer walker.deinit();
    while (try walker.next(io)) |entry| {
        switch (entry.kind) {
            .file, .sym_link => {
                std.debug.print("Copying static file {s}...\n", .{entry.path});
                try entry.dir.copyFile(entry.basename, out_dir, entry.basename, io, .{});
            },
            .directory => {
                const new_out = try out_dir.createDirPathOpen(io, entry.basename, .{ .open_options = .{ .iterate = true } });
                defer new_out.close(io);
                try copyStaticFiles(io, ally, sources_dir, out_dir);
            },

            else => {},
        }
    }
}