#!/usr/bin/env python3
"""Jsonfmt — JSON formatter, validator, and diff tool."""
import argparse, json, sys, difflib, os


def color(text, code):
    return f"\033[{code}m{text}\033[0m" if sys.stdout.isatty() else text


def validate(args):
    errors = 0
    for f in args.files:
        try:
            data = json.load(open(f))
            print(f"{color('✓', '32')} {f} — valid JSON")
            if args.strict and isinstance(data, (list, dict)):
                json.dumps(data, ensure_ascii=args.strict_ascii)
        except (json.JSONDecodeError, FileNotFoundError) as e:
            print(f"{color('✗', '31')} {f} — {e}")
            errors += 1
    return errors


def format_file(args):
    for f in args.files:
        try:
            data = json.load(open(f))
            indent = args.indent or 2
            out = json.dumps(data, indent=indent, sort_keys=args.sort)
            if args.output:
                open(args.output, "w").write(out + "\n")
                print(f"{color('✓', '32')} Formatted → {args.output}")
            else:
                print(out)
        except (json.JSONDecodeError, FileNotFoundError) as e:
            print(f"{color('✗', '31')} {f} — {e}", file=sys.stderr)


def minify(args):
    for f in args.files:
        try:
            data = json.load(open(f))
            out = json.dumps(data, separators=(",", ":"))
            if args.output:
                open(args.output, "w").write(out + "\n")
                print(f"{color('✓', '32')} Minified → {args.output}")
            else:
                print(out)
        except Exception as e:
            print(f"{color('✗', '31')} {f} — {e}", file=sys.stderr)


def diff_files(args):
    if len(args.files) < 2:
        print("diff requires two files", file=sys.stderr)
        return 1
    a, b = args.files[:2]
    try:
        da = json.load(open(a))
        db = json.load(open(b))
    except Exception as e:
        print(f"{color('✗', '31')} {e}", file=sys.stderr)
        return 1

    sa = json.dumps(da, indent=2, sort_keys=True)
    sb = json.dumps(db, indent=2, sort_keys=True)
    diff = difflib.unified_diff(sa.splitlines(), sb.splitlines(),
                                fromfile=a, tofile=b, lineterm="")
    for line in diff:
        if line.startswith("+"):
            print(color(line, "32"))
        elif line.startswith("-"):
            print(color(line, "31"))
        elif line.startswith("@@"):
            print(color(line, "36"))
        else:
            print(line)
    return 0


def main():
    parser = argparse.ArgumentParser(
        description="Jsonfmt — JSON formatter, validator, and diff tool",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog=(
            "Examples:\n"
            "  jsonfmt validate data.json          # Validate JSON\n"
            "  jsonfmt format data.json             # Pretty-print\n"
            "  jsonfmt minify data.json             # Minify\n"
            "  jsonfmt diff a.json b.json           # Diff two files\n"
            "  cat data.json | jsonfmt format -     # Read from stdin\n"
        ),
    )
    parser.add_argument("--version", action="version",
                        version="jsonfmt 1.0.0")

    sub = parser.add_subparsers(dest="command", required=True)

    v = sub.add_parser("validate", help="Validate JSON file(s)")
    v.add_argument("files", nargs="+", help="JSON files to validate")
    v.add_argument("--strict", action="store_true",
                   help="Strict validation")
    v.add_argument("--strict-ascii", action="store_true",
                   help="Enforce ASCII-only output")

    f = sub.add_parser("format", help="Pretty-print JSON")
    f.add_argument("files", nargs="+", help="JSON files to format")
    f.add_argument("--indent", type=int, help="Indent width")
    f.add_argument("--sort", action="store_true", help="Sort keys")
    f.add_argument("-o", "--output", help="Output file")

    m = sub.add_parser("minify", help="Minify JSON")
    m.add_argument("files", nargs="+", help="JSON files to minify")
    m.add_argument("-o", "--output", help="Output file")

    d = sub.add_parser("diff", help="Diff two JSON files")
    d.add_argument("files", nargs=2, help="Two JSON files to compare")

    args = parser.parse_args()

    if args.command == "validate":
        sys.exit(validate(args))
    elif args.command == "format":
        format_file(args)
    elif args.command == "minify":
        minify(args)
    elif args.command == "diff":
        sys.exit(diff_files(args))


if __name__ == "__main__":
    main()