"""Orsync Scenarist — Setup Script.

Run once before starting the project. Installs dependencies, creates the
.env file, validates configuration, checks service connectivity, and
pre-loads models so that ``python run.py`` starts instantly.

Usage:
    python setup.py            # Interactive setup
    python setup.py --check    # Validate only (no installs, no .env creation)
"""
from __future__ import annotations

import argparse
import os
import shutil
import subprocess
import sys
import textwrap

# ── Constants ─────────────────────────────────────────────────────────────────

ROOT_DIR = os.path.dirname(os.path.abspath(__file__))
PROJECT_PARENT = os.path.dirname(ROOT_DIR)
if PROJECT_PARENT not in sys.path:
    sys.path.insert(0, PROJECT_PARENT)

ENV_FILE = os.path.join(ROOT_DIR, ".env")
ENV_EXAMPLE = os.path.join(ROOT_DIR, ".env.example")
REQUIREMENTS = os.path.join(ROOT_DIR, "requirements.txt")
SETUP_MARKER = os.path.join(ROOT_DIR, ".setup_done")

_BOLD = "\033[1m"
_GREEN = "\033[92m"
_YELLOW = "\033[93m"
_RED = "\033[91m"
_CYAN = "\033[96m"
_RESET = "\033[0m"


def _ok(msg: str) -> None:
    print(f"  {_GREEN}✔{_RESET} {msg}")


def _warn(msg: str) -> None:
    print(f"  {_YELLOW}⚠{_RESET} {msg}")


def _fail(msg: str) -> None:
    print(f"  {_RED}✖{_RESET} {msg}")


def _info(msg: str) -> None:
    print(f"  {_CYAN}ℹ{_RESET} {msg}")


def _header(title: str) -> None:
    print(f"\n{_BOLD}── {title} ──{_RESET}")


# ── Step 1: Python version ───────────────────────────────────────────────────

def check_python_version() -> bool:
    _header("Python version")
    major, minor = sys.version_info[:2]
    if (major, minor) >= (3, 12):
        _ok(f"Python {major}.{minor} (>= 3.12 required)")
        return True
    _fail(
        f"Python {major}.{minor} detected — Python >= 3.12 is required.\n"
        "    → Install Python 3.12+ from https://www.python.org/downloads/"
    )
    return False


# ── Step 2: Install dependencies ─────────────────────────────────────────────

def install_dependencies(check_only: bool = False) -> bool:
    _header("Python dependencies")

    missing: list[str] = []
    probes = {
        "fastapi": "fastapi",
        "uvicorn": "uvicorn",
        "ollama": "ollama",
        "redis": "redis",
        "neo4j": "neo4j",
        "chromadb": "chromadb",
        "httpx": "httpx",
        "pydantic_settings": "pydantic-settings",
        "numpy": "numpy",
        "sklearn": "scikit-learn",
        "scipy": "scipy",
        "jose": "python-jose",
        "bcrypt": "bcrypt",
        "aio_pika": "aio-pika",
        "pytest": "pytest",
        "fakeredis": "fakeredis",
    }

    for import_name, pkg_name in probes.items():
        try:
            __import__(import_name)
        except ImportError:
            missing.append(pkg_name)

    if not missing:
        _ok("All dependencies installed")
        return True

    if check_only:
        _fail(f"Missing packages: {', '.join(missing)}")
        _info("Run `python setup.py` (without --check) to install them.")
        return False

    _info(f"Installing {len(missing)} missing packages from requirements.txt ...")
    try:
        uv_cmd = ["uv", "pip", "install", "-r", REQUIREMENTS]
        # uv requires --system when not inside a virtual environment
        if sys.prefix == sys.base_prefix:
            uv_cmd.insert(3, "--system")
        subprocess.check_call(
            uv_cmd,
            stdout=subprocess.DEVNULL if os.name != "nt" else None,
        )
        _ok("All dependencies installed successfully")
        return True
    except subprocess.CalledProcessError:
        _fail(
            "uv pip install failed.\n"
            "    → Try manually: uv pip install -r requirements.txt\n"
            "    → On Windows, run your terminal as Administrator if you get permission errors.\n"
            "    → If a package conflicts, try: uv pip install -r requirements.txt --user"
        )
        return False


# ── Step 3: .env file ────────────────────────────────────────────────────────

def ensure_env_file(check_only: bool = False) -> bool:
    _header("Environment file (.env)")

    if os.path.isfile(ENV_FILE):
        _ok(".env file exists")
        return True

    if check_only:
        _fail(
            ".env file not found.\n"
            "    → Run `python setup.py` to create it from .env.example\n"
            "    → Or manually: copy .env.example .env"
        )
        return False

    if not os.path.isfile(ENV_EXAMPLE):
        _fail(
            ".env.example not found — cannot create .env.\n"
            "    → Ensure you cloned the full repository."
        )
        return False

    shutil.copy(ENV_EXAMPLE, ENV_FILE)
    _ok("Created .env from .env.example")
    _warn("Edit .env to set your OLLAMA_API_KEY and other secrets.")
    return True


# ── Step 4: Validate configuration ──────────────────────────────────────────

def validate_config() -> tuple[bool, dict]:
    _header("Configuration validation")

    # Force-reload settings from the .env we just created/verified
    os.environ.pop("OLLAMA_API_KEY", None)
    try:
        # Clear any stale pydantic module cache before importing
        for mod_name in list(sys.modules):
            if mod_name.startswith(("pydantic", "pydantic_core", "pydantic_settings")):
                del sys.modules[mod_name]

        from pydantic_settings import BaseSettings, SettingsConfigDict

        class _CheckSettings(BaseSettings):
            model_config = SettingsConfigDict(
                env_file=ENV_FILE, env_file_encoding="utf-8", extra="ignore",
            )
            ollama_host: str = "https://ollama.com"
            ollama_api_key: str = ""
            ollama_model: str = "gemma4:31b-cloud"
            embedding_model: str = "onnx-minilm"
            redis_url: str = "redis://localhost:6379/0"
            neo4j_uri: str = "neo4j://localhost:7687"
            neo4j_username: str = "neo4j"
            neo4j_password: str = "scenarist123"
            chroma_host: str = "localhost"
            chroma_port: int = 8100
            environment: str = "development"

        cfg = _CheckSettings()
    except Exception as exc:
        _fail(f"Could not load .env: {exc}")
        _info("Check .env syntax — each line should be KEY=VALUE (no quotes needed).")
        return False, {}

    ok = True
    info = {
        "ollama_api_key": bool(cfg.ollama_api_key),
        "ollama_host": cfg.ollama_host,
        "ollama_model": cfg.ollama_model,
        "embedding_model": cfg.embedding_model,
        "redis_url": cfg.redis_url,
        "neo4j_uri": cfg.neo4j_uri,
        "chroma_host": cfg.chroma_host,
        "chroma_port": cfg.chroma_port,
    }

    # Ollama API key
    if cfg.ollama_api_key:
        _ok(f"OLLAMA_API_KEY is set (host: {cfg.ollama_host})")
    else:
        _warn(
            "OLLAMA_API_KEY is empty — LLM features will use rule-based fallbacks.\n"
            "    → Get a key at https://ollama.com/settings/keys\n"
            "    → Then set OLLAMA_API_KEY in your .env file"
        )

    _ok(f"LLM model: {cfg.ollama_model}")
    _ok(f"Embedding model: {cfg.embedding_model}")

    return ok, info


# ── Step 5: Check service connectivity ───────────────────────────────────────

def check_services(info: dict) -> dict[str, bool]:
    _header("Service connectivity")

    results: dict[str, bool] = {}

    # Redis — now embedded; just check if it's already running
    try:
        import redis as _redis
        r = _redis.from_url(info.get("redis_url", "redis://localhost:6379/0"), socket_connect_timeout=2)
        r.ping()
        _ok(f"Redis: already running ({info.get('redis_url', '')})")
        results["redis"] = True
    except Exception:
        if shutil.which("redis-server"):
            _ok("Redis: redis-server found — will start automatically with run.py")
            results["redis"] = True
        else:
            _warn(
                "Redis: redis-server not installed.\n"
                "    → run.py will start it automatically if installed.\n"
                "    → To install: https://redis.io/download\n"
                "      Windows: winget install Redis.Redis  or  scoop install redis\n"
                "      macOS:   brew install redis\n"
                "      Linux:   sudo apt install redis-server\n"
                "      Docker:  handled automatically in Dockerfile"
            )
            results["redis"] = False

    # Neo4j — embedded; check if running or binary available
    try:
        from neo4j import GraphDatabase
        driver = GraphDatabase.driver(
            info.get("neo4j_uri", "neo4j://localhost:7687"),
            auth=("neo4j", "scenarist"),
        )
        driver.verify_connectivity()
        driver.close()
        _ok(f"Neo4j: already running ({info.get('neo4j_uri', '')})")
        results["neo4j"] = True
    except Exception:
        neo4j_bin = shutil.which("neo4j")
        if not neo4j_bin:
            # Check common install paths
            for candidate in ["/opt/neo4j/bin/neo4j", os.path.expanduser("~/neo4j/bin/neo4j")]:
                if os.path.isfile(candidate):
                    neo4j_bin = candidate
                    break
        if neo4j_bin:
            _ok("Neo4j: binary found — will start automatically with run.py")
            results["neo4j"] = True
        else:
            _warn(
                "Neo4j: not installed.\n"
                "    → run.py will start it automatically if installed.\n"
                "    → To install: https://neo4j.com/download/\n"
                "      Windows: winget install Neo4j.Neo4j  or download from neo4j.com\n"
                "      macOS:   brew install neo4j\n"
                "      Linux:   see https://neo4j.com/docs/operations-manual/current/installation/linux/\n"
                "      Docker:  handled automatically in Dockerfile"
            )
            results["neo4j"] = False

    # ChromaDB — embedded; check if running or binary available
    try:
        import chromadb
        c = chromadb.HttpClient(
            host=info.get("chroma_host", "localhost"),
            port=info.get("chroma_port", 8000),
        )
        c.heartbeat()
        _ok(f"ChromaDB: already running ({info.get('chroma_host', '')}:{info.get('chroma_port', '')})")
        results["chromadb"] = True
    except Exception:
        chroma_bin = shutil.which("chroma")
        if chroma_bin:
            _ok("ChromaDB: chroma CLI found — will start automatically with run.py")
            results["chromadb"] = True
        else:
            _warn(
                "ChromaDB: chroma CLI not installed.\n"
                "    → run.py will start it automatically if installed.\n"
                "    → To install: pip install chromadb\n"
                "      Docker: handled automatically in Dockerfile"
            )
            results["chromadb"] = False

    # Ollama Cloud
    if info.get("ollama_api_key"):
        try:
            from ollama import Client
            headers = {"Authorization": f"Bearer NOT_TESTED"}
            client = Client(host=info.get("ollama_host", "https://ollama.com"))
            # Just check we can reach the host — don't burn tokens
            import httpx
            resp = httpx.get(f"{info.get('ollama_host', 'https://ollama.com')}/api/tags", timeout=5)
            if resp.status_code < 500:
                _ok(f"Ollama Cloud: reachable ({info.get('ollama_host', '')})")
                results["ollama"] = True
            else:
                raise ConnectionError(f"HTTP {resp.status_code}")
        except Exception:
            _warn(
                f"Ollama Cloud: not reachable ({info.get('ollama_host', '')})\n"
                "    → Check your OLLAMA_HOST and internet connection.\n"
                "    → LLM features will use rule-based fallbacks."
            )
            results["ollama"] = False
    else:
        _info("Ollama Cloud: skipped (no API key set)")
        results["ollama"] = False

    return results


# ── Step 6: Pre-load models ──────────────────────────────────────────────────

def preload_models(check_only: bool = False) -> bool:
    _header("Model pre-loading")

    if check_only:
        _info("Skipped in --check mode")
        return True

    # Embedding model
    try:
        from backend.app.core.embedder import EmbeddingRegistry
        reg = EmbeddingRegistry.get()

        # Import settings fresh
        from backend.app.core.config import settings
        _info(f"Loading embedding model: {settings.embedding_model} ...")
        reg.load_model(settings.embedding_model)
        _ok(f"Embedding model ready: {reg.model_name} ({reg.dimension}-dim)")
    except Exception as exc:
        _fail(
            f"Failed to load embedding model: {exc}\n"
            "    → If using 'onnx-minilm' (default), this should work out of the box.\n"
            "    → If using 'ollama:<model>', ensure Ollama is reachable and the model exists."
        )
        return False

    # Projection bridge weights
    try:
        from backend.app.services.projection_bridge import load_weights, is_ready
        _info("Loading projection bridge weights ...")
        load_weights()
        if is_ready():
            _ok("Projection bridge weights loaded")
        else:
            _warn("Projection bridge: using generated default weights (non-critical)")
    except Exception as exc:
        _warn(f"Projection bridge: {exc} (non-critical, will use defaults)")

    return True


# ── Step 7: Write marker ─────────────────────────────────────────────────────

def write_setup_marker() -> None:
    """Write a marker file so run.py knows setup completed successfully."""
    with open(SETUP_MARKER, "w") as f:
        f.write("ok\n")


def is_setup_done() -> bool:
    return os.path.isfile(SETUP_MARKER)


# ── Main ──────────────────────────────────────────────────────────────────────

def main() -> None:
    parser = argparse.ArgumentParser(description="Orsync Scenarist project setup")
    parser.add_argument(
        "--check", action="store_true",
        help="Validate only — do not install packages or create files",
    )
    args = parser.parse_args()

    os.chdir(ROOT_DIR)

    print(f"\n{_BOLD}{'=' * 56}")
    print(f"  Orsync Scenarist — {'Validation' if args.check else 'Setup'}")
    print(f"{'=' * 56}{_RESET}")

    errors: list[str] = []

    # 1. Python
    if not check_python_version():
        errors.append("Python >= 3.12")

    # 2. Dependencies
    if not install_dependencies(check_only=args.check):
        errors.append("Python dependencies")

    # 3. .env
    if not ensure_env_file(check_only=args.check):
        errors.append(".env file")

    # 4. Config validation
    config_ok, info = validate_config()
    if not config_ok:
        errors.append("Configuration")

    # 5. Service connectivity
    svc = check_services(info)

    # 6. Pre-load models
    if not errors:
        if not preload_models(check_only=args.check):
            errors.append("Model pre-loading")

    # Summary
    _header("Summary")
    if errors:
        _fail(f"Setup {'validation' if args.check else ''} completed with errors:")
        for e in errors:
            print(f"       - {e}")
        print()
        _info("Fix the issues above and re-run: python setup.py")
        sys.exit(1)
    else:
        if not args.check:
            write_setup_marker()
        svc_up = sum(1 for v in svc.values() if v)
        svc_total = len(svc)
        _ok(f"All checks passed — {svc_up}/{svc_total} optional services connected")
        if not info.get("ollama_api_key"):
            _warn(
                "OLLAMA_API_KEY not set — LLM features will use rule-based fallbacks.\n"
                "    → Set it in .env when you have a key from https://ollama.com/settings/keys"
            )
        print()
        if not args.check:
            print(f"  {_GREEN}Ready! Start the server:{_RESET}")
            print(f"    python run.py")
            print(f"    python run.py --reload   # dev mode with auto-reload")
        print()


if __name__ == "__main__":
    main()