// Reads a stock list and writes it as an HTML page, largest count first,
// from three files: this one, `stock.nika` (the parse) and `page.nika` (the page).
//
//     printf 'tools;Bolts & Nuts;12\npaper;<plain> A4;40\n' > stock.csv
//     nikaia run -- stock.csv report.html
//     2 items, 52 in total
//
// Shows: one package in several files, and `pub`.
//
// A package: `nikaia run` in this directory runs it, and `nikaia test` checks what
// it prints and the page it writes against `tests/` (ADR-247), and runs the test
// at the end of this file.
//
// A package is a directory, and its files share one namespace. So there is no
// `use` between them: `read`, `total` and `render` are simply called here.
// `pub` means visible outside the package, not outside the file.

use std::fs
use std::cli

fn main() throws {
    let path = cli::args().nth(1) ?? "stock.csv"
    let out = cli::args().nth(2) ?? "report.html"

    let data = fs::map(ref path, fs::Root::Anywhere) catch {
        eprintln(f"cannot open {path}: {error}")
        return
    }

    let mut entries = read(data.text()) catch {
        eprintln(f"{path}: {error}")
        return
    }

    entries.sort_by_key fn (entry) { -entry.count }

    let total = total(entries)
    let count = entries.len()
    let markup = render(entries, total)

    fs::write(ref out, fs::Root::Anywhere, ref markup) catch {
        eprintln(f"cannot write {out}: {error}")
        return
    }

    println(f"{count} items, {total} in total")
}

// **A test writes under a root of its own** (ADR-247 D5): `fs::scratch()` is a
// fresh directory, removed when the test ends, and the page goes under it the
// way `main` writes it anywhere.
test "the page escapes the stock file, and is written as it was made" {
    let entries = read("tools;Bolts & Nuts;12\n")
    let page = render(entries, 12)
    assert(page.contains("Bolts &amp; Nuts"))
    let root = fs::scratch()
    fs::write("page.html", root, ref page)
    let back = fs::read_to_string("page.html", root)
    assert(back == page)
}