#!/usr/bin/env python3
"""
DSS Token Resolver - 3-Layer Cascade
Merges tokens from Core → Skin → Theme into a single style-dictionary input.

Usage: python3 scripts/resolve-tokens.py [--skin SKIN] [--theme THEME] [--output PATH]

Default: --skin shadcn --theme default --output .dss/data/_system/tokens/tokens.json
"""

import sys
import os
import json
import re
import argparse
from pathlib import Path
from datetime import datetime
from typing import Dict, Any

DSS_ROOT = Path(__file__).parent.parent
DSS_DATA = DSS_ROOT / ".dss"

# Primitive path aliases - map shorthand refs to full primitive paths
# The translation dictionary maps: {color.white} → color.base.white
PRIMITIVE_ALIASES = {
    # Base colors
    "color.white": "color.base.white",
    "color.black": "color.base.black",
    "color.transparent": "color.base.transparent",
}

# Generate aliases for neutral color scales (zinc, slate, gray, etc.)
NEUTRAL_SCALES = ["slate", "gray", "zinc", "neutral", "stone"]
SEMANTIC_SCALES = ["red", "orange", "amber", "yellow", "lime", "green", "emerald",
                   "teal", "cyan", "sky", "blue", "indigo", "violet", "purple",
                   "fuchsia", "pink", "rose"]
SCALE_VALUES = ["50", "100", "200", "300", "400", "500", "600", "700", "800", "900", "950"]

for scale in NEUTRAL_SCALES:
    for val in SCALE_VALUES:
        # color.zinc.50 → color.neutral.zinc.50
        PRIMITIVE_ALIASES[f"color.{scale}.{val}"] = f"color.neutral.{scale}.{val}"

for scale in SEMANTIC_SCALES:
    for val in SCALE_VALUES:
        # color.red.500 → color.semantic.red.500
        PRIMITIVE_ALIASES[f"color.{scale}.{val}"] = f"color.semantic.{scale}.{val}"


def load_json(path: Path) -> dict:
    """Load JSON file, return empty dict if not found"""
    if not path.exists():
        return {}
    with open(path) as f:
        return json.load(f)


def deep_merge(base: dict, override: dict) -> dict:
    """Deep merge override into base, returning new dict"""
    result = base.copy()
    for key, value in override.items():
        if key.startswith("_"):
            continue  # Skip metadata keys
        if key in result and isinstance(result[key], dict) and isinstance(value, dict):
            result[key] = deep_merge(result[key], value)
        else:
            result[key] = value
    return result


def resolve_references(tokens: dict, primitives: dict) -> dict:
    """
    Resolve token references like {color.zinc.500} using primitives.
    Uses translation dictionary (PRIMITIVE_ALIASES) to map shorthand paths.
    Works recursively through the token structure.
    """
    ref_pattern = re.compile(r'\{([^}]+)\}')
    unresolved = []

    def get_nested(obj: dict, path: str) -> Any:
        """Get nested value from dict using dot notation"""
        parts = path.split(".")
        current = obj
        for part in parts:
            if isinstance(current, dict) and part in current:
                current = current[part]
            else:
                return None
        # If we found a token object with 'value', return the value
        if isinstance(current, dict) and "value" in current:
            return current["value"]
        return current

    def resolve_value(value: Any) -> Any:
        """Resolve references in a value"""
        if not isinstance(value, str):
            return value

        def replacer(match):
            ref_path = match.group(1)

            # First: try direct lookup in primitives
            resolved = get_nested(primitives, ref_path)
            if resolved is not None:
                return str(resolved)

            # Second: try using translation dictionary (alias mapping)
            aliased_path = PRIMITIVE_ALIASES.get(ref_path)
            if aliased_path:
                resolved = get_nested(primitives, aliased_path)
                if resolved is not None:
                    return str(resolved)

            # Third: try in tokens themselves (for self-references)
            resolved = get_nested(tokens, ref_path)
            if resolved is not None:
                return str(resolved)

            # Track unresolved for debugging
            if ref_path not in unresolved:
                unresolved.append(ref_path)

            # Return original if not found
            return match.group(0)

        return ref_pattern.sub(replacer, value)

    def resolve_obj(obj: Any) -> Any:
        """Recursively resolve references in object"""
        if isinstance(obj, dict):
            result = {}
            for key, value in obj.items():
                if key.startswith("_"):
                    continue  # Skip metadata
                if key == "value":
                    result[key] = resolve_value(value)
                else:
                    result[key] = resolve_obj(value)
            return result
        elif isinstance(obj, list):
            return [resolve_obj(item) for item in obj]
        else:
            return obj

    resolved = resolve_obj(tokens)

    # Report unresolved references
    if unresolved:
        print(f"[WARN] {len(unresolved)} unresolved token references:")
        for ref in unresolved[:10]:  # Show first 10
            alias = PRIMITIVE_ALIASES.get(ref, "no alias")
            print(f"  - {{{ref}}} (alias: {alias})")
        if len(unresolved) > 10:
            print(f"  ... and {len(unresolved) - 10} more")

    return resolved


def resolve_tokens(
    skin_name: str = "shadcn",
    theme_name: str = "default"
) -> Dict[str, Any]:
    """
    Resolve tokens through the 3-layer cascade:
    1. Core primitives (base values)
    2. Skin tokens (semantic mappings)
    3. Theme overrides (brand customization)
    """
    # Load each layer
    primitives = load_json(DSS_DATA / "core" / "primitives.json")
    skin = load_json(DSS_DATA / "skins" / skin_name / "tokens.json")
    theme = load_json(DSS_DATA / "themes" / f"{theme_name}.json")

    # Report what we're loading
    print(f"[INFO] Resolving tokens:")
    print(f"  Core: {len(primitives)} categories")
    print(f"  Skin: {skin_name}")
    print(f"  Theme: {theme_name}")

    # Start with skin as base (it references primitives)
    merged = {}

    # Copy skin tokens
    for category, tokens in skin.items():
        if category.startswith("_"):
            continue
        merged[category] = tokens.copy() if isinstance(tokens, dict) else tokens

    # Override with theme tokens
    for category, tokens in theme.items():
        if category.startswith("_"):
            continue
        if category in merged:
            merged[category] = deep_merge(merged[category], tokens)
        else:
            merged[category] = tokens

    # Resolve all references using primitives
    resolved = resolve_references(merged, primitives)

    # Clean up internal metadata
    def clean_tokens(obj):
        if isinstance(obj, dict):
            return {
                k: clean_tokens(v)
                for k, v in obj.items()
                if not k.startswith("_")
            }
        return obj

    resolved = clean_tokens(resolved)

    return resolved


def main():
    parser = argparse.ArgumentParser(description="Resolve DSS 3-layer token cascade")
    parser.add_argument("--skin", default="shadcn", help="Skin to use (default: shadcn)")
    parser.add_argument("--theme", default="default", help="Theme to use (default: default)")
    parser.add_argument("--output", default=".dss/data/_system/tokens/tokens.json",
                        help="Output path for resolved tokens")
    parser.add_argument("--dry-run", action="store_true", help="Print tokens without saving")
    args = parser.parse_args()

    print("=" * 60)
    print("DSS TOKEN RESOLVER - 3-Layer Cascade")
    print("=" * 60)
    print("")

    # Resolve tokens
    tokens = resolve_tokens(args.skin, args.theme)

    # Count tokens
    total = 0
    for category, items in tokens.items():
        if isinstance(items, dict):
            total += len(items)

    print(f"\n[OK] Resolved {total} tokens")

    if args.dry_run:
        print("\n[DRY RUN] Resolved tokens:")
        print(json.dumps(tokens, indent=2))
    else:
        # Save to output path
        output_path = Path(args.output)
        if not output_path.is_absolute():
            output_path = DSS_ROOT / output_path

        output_path.parent.mkdir(parents=True, exist_ok=True)
        with open(output_path, "w") as f:
            json.dump(tokens, f, indent=2)
        print(f"[OK] Saved to {output_path}")

        # Also save metadata
        meta_path = output_path.parent / "resolved-meta.json"
        with open(meta_path, "w") as f:
            json.dump({
                "resolved_at": datetime.now().isoformat(),
                "skin": args.skin,
                "theme": args.theme,
                "token_count": total,
                "layers": ["core/primitives", f"skins/{args.skin}", f"themes/{args.theme}"]
            }, f, indent=2)

    print("")
    print("[OK] Token resolution complete!")
    print("  Next: Run style-dictionary build")


if __name__ == "__main__":
    main()