import os
import flag
import term
import arrays.diff

fn main() {
    mut fp := flag.new_flag_parser(os.args[1..])
    fp.application('v diff')
    fp.version('0.0.1')
    fp.description('Compare files line by line. Example: `v diff examples/hello_world.v examples/log.v`')
    fp.arguments_description('file1 file2')
    fp.skip_executable()
    fp.limit_free_args_to_at_least(2)!

    if fp.bool('help', `h`, false, 'Show this help screen.') {
        println(fp.usage())
        exit(0)
    }

    args := fp.finalize() or {
        eprintln('Argument error: ${err}')
        exit(1)
    }

    src := os.read_lines(args[0])!
    dst := os.read_lines(args[1])!
    mut ctx := diff.diff(src, dst)
    patch := ctx.generate_patch(
        colorful:     term.can_show_color_on_stdout()
        block_header: true
        unified:      3
    )
    if patch.len > 0 {
        print(patch)
        exit(1)
    }
}