import os
from pathlib import Path
from typing import Any

import yaml
from pydantic import Field
from pydantic_settings import BaseSettings, SettingsConfigDict


class InvestibookSettings(BaseSettings):
    """Investibook configuration loaded from YAML file and environment variables.

    Priority: Environment variables > YAML file > defaults

    Environment variables use the prefix INVESTIBOOK_, e.g.:
    - INVESTIBOOK_AIOPS_API_URL
    - INVESTIBOOK_S3_BUCKET
    - INVESTIBOOK_CLINIC_API_KEY
    """

    # Guardian API
    aiops_api_url: str = Field(
        default="", description="Guardian API base URL (e.g., http://localhost:9090)"
    )

    # S3
    s3_bucket: str = Field(default="", description="S3 bucket name for analysis files")
    aws_region: str = Field(default="us-west-2", description="AWS region for S3 bucket")
    # Note: AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_PROFILE are read by boto3 natively

    # Workspace export to S3
    export_s3_prefix: str = Field(
        default="investibook_service/export_workspaces",
        description="S3 key prefix for workspace export archives. Env: INVESTIBOOK_EXPORT_S3_PREFIX",
    )

    # Clinic
    clinic_endpoint: str = Field(
        default="https://clinic.pingcap.com", description="Clinic HTTP API endpoint"
    )
    clinic_api_key: str = Field(
        default="", description="Clinic API key for authentication"
    )
    clinic_cookie: str = Field(
        default="",
        description="Clinic cookie for local debugging (alternative to API key)",
    )
    clinic_csrf_token: str = Field(
        default="",
        description="Clinic CSRF token for local debugging (used with cookie)",
    )

    # Jira
    jira_base_url: str = Field(
        default="https://tidb.atlassian.net", description="Jira base URL"
    )
    jira_username: str = Field(default="", description="Jira username (email)")
    jira_api_token: str = Field(
        default="", description="Jira API token for authentication"
    )
    skip_jira_comments: bool = Field(
        default=False,
        description="If true, skip fetching/writing Jira comments during issue prepare (no comments.json / comments_summary_ai.md). Env: INVESTIBOOK_SKIP_JIRA_COMMENTS",
    )

    # Alertstore (shares the DevOps gateway; ALT-* alerts)
    devops_base_url: str = Field(
        default_factory=lambda: (
            os.environ.get("DEVOPS_BASE_URL")
            or os.environ.get("DEVOPS_BASE_DOMAIN")
            or "https://prod.devops.pingcap.com"
        ),
        description="DevOps gateway base URL for alertstore",
    )
    devops_api_token: str = Field(
        default_factory=lambda: (
            os.environ.get("DEVOPS_API_KEY") or os.environ.get("DEVOPS_API_TOKEN") or ""
        ),
        description="DevOps gateway API key (X-API-KEY) for alertstore",
    )

    # LLM for comment summary (direct OpenAI call, no ACP agent)
    openai_api_key: str = Field(
        default="",
        description="OpenAI API key for comment summarization. Env: INVESTIBOOK_OPENAI_API_KEY",
    )
    openai_model: str = Field(
        default="gpt-4o",
        description="OpenAI model name for comment summarization",
    )

    model_config = SettingsConfigDict(
        env_prefix="INVESTIBOOK_",
        env_file=".env",
        env_file_encoding="utf-8",
        extra="ignore",
    )


def load_settings() -> InvestibookSettings:
    """Load settings from YAML file and environment variables.

    Looks for config file in the following locations (in order):
    1. INVESTIBOOK_CONFIG_FILE environment variable
    2. ../config.yaml (parent directory, for backend/)
    3. ../investibook.yaml (parent directory)
    4. ./investibook.yaml (current directory)
    5. ./config/investibook.yaml
    6. ~/.investibook/config.yaml

    Priority: Environment variables > YAML file > defaults

    Returns:
        InvestibookSettings instance with loaded configuration
    """
    # First create settings from env vars and defaults
    settings = InvestibookSettings()

    # Try to find and load YAML config file
    config_paths = [
        Path(os.environ.get("INVESTIBOOK_CONFIG_FILE", "")),
        Path("../config.yaml"),  # Parent directory (for backend/)
        Path("../investibook.yaml"),  # Parent directory
        Path("investibook.yaml"),
        Path("config/investibook.yaml"),
        Path.home() / ".investibook" / "config.yaml",
    ]

    yaml_data: dict[str, Any] = {}
    loaded_path = None

    for config_path in config_paths:
        if config_path.exists() and config_path.is_file():
            try:
                with open(config_path, "r") as f:
                    yaml_data = yaml.safe_load(f) or {}
                loaded_path = config_path
                print(f"Loaded configuration from {config_path}")
                break
            except Exception as e:
                print(f"Warning: Failed to load config from {config_path}: {e}")

    # Merge YAML values only for fields that weren't set via environment
    # Environment variables use the INVESTIBOOK_ prefix and are already loaded
    if yaml_data and loaded_path:
        for field_name, yaml_value in yaml_data.items():
            # Check if env var exists for this field
            env_var_name = f"INVESTIBOOK_{field_name.upper()}"
            if env_var_name not in os.environ:
                # No env var, so use YAML value if current value is default
                if hasattr(settings, field_name):
                    setattr(settings, field_name, yaml_value)

    return settings


settings = load_settings()