from __future__ import annotations

from functools import lru_cache
from pathlib import Path

from pydantic import Field
from pydantic_settings import BaseSettings, SettingsConfigDict

ROOT_DIR = Path(__file__).resolve().parents[2]


class Settings(BaseSettings):
    app_name: str = Field(default="Recruitment Agent API", validation_alias="APP_NAME")
    environment: str = Field(default="development", validation_alias="APP_ENV")
    host: str = Field(default="0.0.0.0", validation_alias="APP_HOST")
    port: int = Field(default=7860, validation_alias="APP_PORT")
    cors_origins: str = Field(default="*", validation_alias="CORS_ORIGINS")

    gemini_api_key: str = Field(default="", validation_alias="GEMINI_API_KEY")
    gemini_model: str = Field(default="gemini-2.5-flash", validation_alias="GEMINI_MODEL")
    embedding_model: str = Field(
        default="models/text-embedding-004",
        validation_alias="GEMINI_EMBEDDING_MODEL",
    )

    qdrant_url: str | None = Field(default=None, validation_alias="QDRANT_URL")
    qdrant_api_key: str | None = Field(default=None, validation_alias="QDRANT_API_KEY")
    qdrant_collection: str = Field(
        default="recruitment_candidates",
        validation_alias="QDRANT_COLLECTION",
    )

    # Generic S3-compatible storage. Works with Supabase Storage, Backblaze B2,
    # AWS S3, MinIO, etc. — just point S3_ENDPOINT at the provider's URL.
    s3_endpoint: str | None = Field(default=None, validation_alias="S3_ENDPOINT")
    s3_access_key_id: str | None = Field(default=None, validation_alias="S3_ACCESS_KEY_ID")
    s3_secret_access_key: str | None = Field(
        default=None,
        validation_alias="S3_SECRET_ACCESS_KEY",
    )
    s3_bucket: str | None = Field(default=None, validation_alias="S3_BUCKET")
    s3_region: str = Field(default="us-east-1", validation_alias="S3_REGION")
    s3_public_base_url: str | None = Field(
        default=None,
        validation_alias="S3_PUBLIC_BASE_URL",
    )

    sqlite_db_path: str = Field(
        default=str(ROOT_DIR / "backend" / "data" / "candidates.db"),
        validation_alias="SQLITE_DB_PATH",
    )
    uploads_dir: str = Field(
        default=str(ROOT_DIR / "backend" / "data" / "uploads"),
        validation_alias="UPLOADS_DIR",
    )

    mcp_server_base_url: str = Field(
        default="http://127.0.0.1:7860/mcp-server/sse",
        validation_alias="MCP_SERVER_BASE_URL",
    )

    chunk_size: int = Field(default=1100, validation_alias="CHUNK_SIZE")
    chunk_overlap: int = Field(default=150, validation_alias="CHUNK_OVERLAP")
    max_chunks_per_document: int = Field(default=50, validation_alias="MAX_CHUNKS_PER_DOC")

    smtp_host: str | None = Field(default=None, validation_alias="SMTP_HOST")
    smtp_port: int = Field(default=587, validation_alias="SMTP_PORT")
    smtp_user: str | None = Field(default=None, validation_alias="SMTP_USER")
    smtp_password: str | None = Field(default=None, validation_alias="SMTP_PASSWORD")
    smtp_from: str | None = Field(default=None, validation_alias="SMTP_FROM")
    smtp_use_tls: bool = Field(default=True, validation_alias="SMTP_USE_TLS")
    # Resend (https://resend.com) — HTTPS email API. Free 3000/month but
    # restricted to your own email address until you verify a sending domain.
    resend_api_key: str | None = Field(default=None, validation_alias="RESEND_API_KEY")
    # Brevo (https://brevo.com, formerly Sendinblue) — HTTPS email API. Free
    # 300 emails/day. Only needs a *single sender email* verified (no DNS
    # required), and you can send TO any recipient. Best free option when the
    # demo needs to email arbitrary addresses on day one.
    brevo_api_key: str | None = Field(default=None, validation_alias="BREVO_API_KEY")
    calendly_event_url: str | None = Field(default=None, validation_alias="CALENDLY_EVENT_URL")

    model_config = SettingsConfigDict(
        env_file=(str(ROOT_DIR / ".env"), str(ROOT_DIR.parent / ".env")),
        env_file_encoding="utf-8",
        extra="ignore",
    )

    @property
    def sqlite_url(self) -> str:
        return f"sqlite:///{Path(self.sqlite_db_path).resolve()}"

    @property
    def cors_origin_list(self) -> list[str]:
        if self.cors_origins.strip() == "*":
            return ["*"]
        return [item.strip() for item in self.cors_origins.split(",") if item.strip()]

    @property
    def has_qdrant_config(self) -> bool:
        return bool(self.qdrant_url and self.qdrant_api_key)

    @property
    def has_s3_config(self) -> bool:
        return bool(
            self.s3_endpoint
            and self.s3_access_key_id
            and self.s3_secret_access_key
            and self.s3_bucket
        )

    @property
    def has_smtp_config(self) -> bool:
        return bool(self.smtp_host and self.smtp_from)


@lru_cache(maxsize=1)
def get_settings() -> Settings:
    return Settings()