// Cthulhu screen reader.
// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <https://www.gnu.org/licenses/gpl-3.0.html>.

package main

import (
	"fmt"
	"io"
	"os"

	"git.stormux.org/storm/cthulhu/internal/parity"
)

func main() {
	if err := run(os.Args[1:], os.Stdout, os.Stderr); err != nil {
		fmt.Fprintf(os.Stderr, "parityledger: %v\n", err)
		os.Exit(1)
	}
}

func run(arguments []string, stdout, stderr io.Writer) error {
	if len(arguments) == 1 && (arguments[0] == "-h" || arguments[0] == "--help") {
		writeUsage(stdout)
		return nil
	}
	if len(arguments) != 2 || arguments[0] != "validate" {
		writeUsage(stderr)
		return fmt.Errorf("expected validate LEDGER")
	}

	file, err := os.Open(arguments[1])
	if err != nil {
		return fmt.Errorf("open parity ledger: %w", err)
	}
	defer file.Close()

	records, err := parity.Load(file)
	if err != nil {
		return fmt.Errorf("validate parity ledger: %w", err)
	}
	fmt.Fprintf(stdout, "Validated %d parity ledger rows.\n", len(records))
	return nil
}

func writeUsage(writer io.Writer) {
	fmt.Fprintln(writer, "Usage: parityledger validate LEDGER")
	fmt.Fprintln(writer)
	fmt.Fprintln(writer, "Validates the schema, required fields, statuses, and duplicate row IDs.")
	fmt.Fprintln(writer)
	fmt.Fprintf(writer, "Allowed statuses: %s.\n", parity.FormatStatuses())
}