"""
outfit_db.py — AI Outfit Storage Layer
────────────────────────────────────────────────────────────
Manages 2 tables:
  • dashboard_canifa.ai_outfit_set   (1 row per source_code + occasion_tag)
  • dashboard_canifa.ai_outfit_items (N rows per set: target_code, role, rank, score)

Backend switching via env:
  USE_LOCAL_SQLITE=true  → SQLite (local dev / home)
  USE_LOCAL_SQLITE=false → Postgres (company / production)

Usage:
  from common.outfit_db import OutfitDB

  # Lưu outfit từ engine
  OutfitDB.save_outfit("8TS25S012", "di_choi", items=[
      {"target_code": "8BJ25A002", "role": "bottom", "rank": 1, "score": 87, "reason": "..."},
      {"target_code": "8JK25A001", "role": "outer",  "rank": 1, "score": 80, "reason": "..."},
  ])

  # Đọc outfit cho FE
  data = OutfitDB.get_outfit("8TS25S012")
  # → {"di_choi": {"bottom": [...], "outer": [...]}, "di_lam": {...}}

  # Stylist pin 1 item
  OutfitDB.pin_item(item_id=42, is_pinned=True)
"""

import logging
import os
import sqlite3
from typing import Optional

logger = logging.getLogger(__name__)

SCHEMA      = "dashboard_canifa"
SET_TABLE   = f"{SCHEMA}.ai_outfit_set"
ITEMS_TABLE = f"{SCHEMA}.ai_outfit_items"

USE_SQLITE = os.getenv("USE_LOCAL_SQLITE", "false").strip().lower() == "true"

from common.constants import SQLITE_DB_PATH

SQLITE_PATH = os.getenv("SQLITE_PATH", SQLITE_DB_PATH)
SQLITE_PATH = os.path.abspath(SQLITE_PATH)

# Alias bảng cho SQLite (không có schema prefix)
_SET   = "ai_outfit_set"   if USE_SQLITE else SET_TABLE
_ITEMS = "ai_outfit_items" if USE_SQLITE else ITEMS_TABLE

__all__ = ["OutfitDB"]


# ─── Connection helpers ────────────────────────────────────────────────────────

def _get_conn():
    """Return a DB connection (SQLite hoặc Postgres tuỳ env)."""
    if USE_SQLITE:
        conn = sqlite3.connect(SQLITE_PATH)
        conn.row_factory = sqlite3.Row
        conn.execute("PRAGMA foreign_keys = ON")
        return conn
    else:
        from common.pool_wrapper import get_pooled_connection_compat
        return get_pooled_connection_compat()


def _fetchall_as_dicts(cur) -> list[dict]:
    """Normalize cursor rows to list[dict] for both SQLite & Postgres."""
    rows = cur.fetchall()
    if not rows:
        return []
    if isinstance(rows[0], dict):
        return [dict(r) for r in rows]
    cols = [d[0] for d in cur.description]
    return [dict(zip(cols, r)) for r in rows]


# ─── DDL ──────────────────────────────────────────────────────────────────────

_SQLITE_DDL = """
CREATE TABLE IF NOT EXISTS ai_outfit_set (
    id           INTEGER PRIMARY KEY AUTOINCREMENT,
    source_code  TEXT    NOT NULL,
    occasion_tag TEXT    NOT NULL,
    created_at   TEXT    DEFAULT (datetime('now')),
    updated_at   TEXT    DEFAULT (datetime('now')),
    UNIQUE (source_code, occasion_tag)
);
CREATE INDEX IF NOT EXISTS idx_outfit_set_source ON ai_outfit_set(source_code);

CREATE TABLE IF NOT EXISTS ai_outfit_items (
    id          INTEGER PRIMARY KEY AUTOINCREMENT,
    outfit_id   INTEGER NOT NULL REFERENCES ai_outfit_set(id) ON DELETE CASCADE,
    target_code TEXT    NOT NULL,
    role        TEXT    NOT NULL,
    rank        INTEGER NOT NULL DEFAULT 1,
    score       INTEGER DEFAULT 0,
    reason      TEXT    DEFAULT '',
    is_pinned   INTEGER DEFAULT 0,
    created_at  TEXT    DEFAULT (datetime('now'))
);
CREATE INDEX IF NOT EXISTS idx_outfit_items_outfit_id ON ai_outfit_items(outfit_id);
CREATE INDEX IF NOT EXISTS idx_outfit_items_target    ON ai_outfit_items(target_code);
"""

_POSTGRES_DDL = f"""
CREATE SCHEMA IF NOT EXISTS {SCHEMA};

CREATE TABLE IF NOT EXISTS {SET_TABLE} (
    id           SERIAL PRIMARY KEY,
    source_code  VARCHAR(50)  NOT NULL,
    occasion_tag VARCHAR(50)  NOT NULL,
    created_at   TIMESTAMPTZ  DEFAULT NOW(),
    updated_at   TIMESTAMPTZ  DEFAULT NOW(),
    UNIQUE (source_code, occasion_tag)
);

CREATE INDEX IF NOT EXISTS idx_outfit_set_source ON {SET_TABLE}(source_code);

CREATE TABLE IF NOT EXISTS {ITEMS_TABLE} (
    id          SERIAL PRIMARY KEY,
    outfit_id   INT          NOT NULL REFERENCES {SET_TABLE}(id) ON DELETE CASCADE,
    target_code VARCHAR(50)  NOT NULL,
    role        VARCHAR(30)  NOT NULL,
    rank        SMALLINT     NOT NULL DEFAULT 1,
    score       SMALLINT     DEFAULT 0,
    reason      TEXT         DEFAULT '',
    is_pinned   BOOLEAN      DEFAULT FALSE,
    created_at  TIMESTAMPTZ  DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_outfit_items_outfit_id ON {ITEMS_TABLE}(outfit_id);
CREATE INDEX IF NOT EXISTS idx_outfit_items_target    ON {ITEMS_TABLE}(target_code);
"""


# ─── Main class ───────────────────────────────────────────────────────────────

class OutfitDB:
    """Static helper class — manages ai_outfit_set + ai_outfit_items."""

    _initialized: bool = False

    @classmethod
    def ensure_tables(cls) -> None:
        """Create tables if they don't exist (idempotent)."""
        if cls._initialized:
            return
        conn = None
        try:
            conn = _get_conn()
            if USE_SQLITE:
                conn.executescript(_SQLITE_DDL)
                conn.commit()
            else:
                cur = conn.cursor()
                for stmt in _POSTGRES_DDL.split(";"):
                    stmt = stmt.strip()
                    if stmt:
                        cur.execute(stmt)
                conn.commit()
                cur.close()
            cls._initialized = True
            backend = "SQLite" if USE_SQLITE else "Postgres"
            logger.info("[OutfitDB] ✅ Tables ready (%s): %s + %s", backend, _SET, _ITEMS)
        except Exception as e:
            logger.error("[OutfitDB] ensure_tables error: %s", e)
        finally:
            if conn:
                conn.close()

    # ── Write ──────────────────────────────────────────────────────────────────

    @classmethod
    def save_outfit(
        cls,
        source_code: str,
        occasion_tag: str,
        items: list[dict],
    ) -> Optional[int]:
        """
        Upsert 1 outfit set và replace toàn bộ items của nó.

        items: list of dicts with keys:
            target_code (str), role (str), rank (int), score (int), reason (str)

        Returns: outfit_id hoặc None nếu lỗi.
        """
        cls.ensure_tables()
        conn = None
        try:
            conn = _get_conn()
            cur = conn.cursor()

            # 1. Upsert ai_outfit_set → lấy id
            if USE_SQLITE:
                cur.execute(
                    f"""INSERT INTO {_SET} (source_code, occasion_tag, updated_at)
                        VALUES (?, ?, datetime('now'))
                        ON CONFLICT(source_code, occasion_tag)
                        DO UPDATE SET updated_at = datetime('now')""",
                    (source_code, occasion_tag),
                )
                cur.execute(
                    f"SELECT id FROM {_SET} WHERE source_code = ? AND occasion_tag = ?",
                    (source_code, occasion_tag),
                )
            else:
                cur.execute(
                    f"""INSERT INTO {_SET} (source_code, occasion_tag, updated_at)
                        VALUES (%s, %s, NOW())
                        ON CONFLICT(source_code, occasion_tag)
                        DO UPDATE SET updated_at = NOW()
                        RETURNING id""",
                    (source_code, occasion_tag),
                )
                if cur.rowcount == 0 or cur.description is None:
                    # ON CONFLICT did not return — fetch manually
                    cur.execute(
                        f"SELECT id FROM {_SET} WHERE source_code = %s AND occasion_tag = %s",
                        (source_code, occasion_tag),
                    )

            row = cur.fetchone()
            outfit_id = row[0] if row else None
            if not outfit_id:
                logger.error("[OutfitDB] Could not get outfit_id for %s/%s", source_code, occasion_tag)
                return None

            # 2. Delete old items (non-pinned)
            if USE_SQLITE:
                cur.execute(f"DELETE FROM {_ITEMS} WHERE outfit_id = ? AND is_pinned = 0", (outfit_id,))
            else:
                cur.execute(f"DELETE FROM {_ITEMS} WHERE outfit_id = %s AND is_pinned = FALSE", (outfit_id,))

            # 3. Insert new items
            if items:
                if USE_SQLITE:
                    cur.executemany(
                        f"""INSERT INTO {_ITEMS} (outfit_id, target_code, role, rank, score, reason, is_pinned)
                            VALUES (?, ?, ?, ?, ?, ?, 0)""",
                        [(outfit_id, item["target_code"], item["role"], item.get("rank", 1), item.get("score", 0), item.get("reason", "")) for item in items]
                    )
                else:
                    cur.executemany(
                        f"""INSERT INTO {_ITEMS} (outfit_id, target_code, role, rank, score, reason, is_pinned)
                            VALUES (%s, %s, %s, %s, %s, %s, FALSE)""",
                        [(outfit_id, item["target_code"], item["role"], item.get("rank", 1), item.get("score", 0), item.get("reason", "")) for item in items]
                    )

            conn.commit()
            if not USE_SQLITE:
                cur.close()
            return outfit_id

        except Exception as e:
            if conn:
                conn.rollback()
            logger.error("[OutfitDB] save_outfit error %s/%s: %s", source_code, occasion_tag, e)
            return None
        finally:
            if conn:
                conn.close()

    # ── Read ───────────────────────────────────────────────────────────────────

    @classmethod
    def get_outfit(cls, source_code: str) -> dict:
        """
        Lấy toàn bộ outfit cho 1 sản phẩm.

        Returns:
        {
          "di_choi": {
            "bottom": [{"target_code": ..., "role": ..., "rank": ..., "score": ..., "reason": ..., "is_pinned": ...}],
            "outer":  [...],
          },
          "di_lam": {...},
        }
        """
        cls.ensure_tables()
        conn = None
        try:
            conn = _get_conn()
            cur = conn.cursor()

            if USE_SQLITE:
                cur.execute(
                    f"""SELECT s.occasion_tag, i.target_code, i.role, i.rank, i.score, i.reason, i.is_pinned, i.id
                        FROM {_SET} s
                        JOIN {_ITEMS} i ON i.outfit_id = s.id
                        WHERE s.source_code = ?
                        ORDER BY s.occasion_tag, i.role, i.rank""",
                    (source_code,),
                )
            else:
                cur.execute(
                    f"""SELECT s.occasion_tag, i.target_code, i.role, i.rank, i.score, i.reason, i.is_pinned, i.id
                        FROM {_SET} s
                        JOIN {_ITEMS} i ON i.outfit_id = s.id
                        WHERE s.source_code = %s
                        ORDER BY s.occasion_tag, i.role, i.rank""",
                    (source_code,),
                )

            rows = cur.fetchall()
            if not USE_SQLITE:
                cur.close()

            result: dict[str, dict[str, list]] = {}
            for row in rows:
                occ, tgt, role, rank, score, reason, is_pinned, item_id = row
                if occ not in result:
                    result[occ] = {}
                if role not in result[occ]:
                    result[occ][role] = []
                result[occ][role].append({
                    "id": item_id,
                    "target_code": tgt,
                    "role": role,
                    "rank": rank,
                    "score": score,
                    "reason": reason or "",
                    "is_pinned": bool(is_pinned),
                })
            return result

        except Exception as e:
            logger.error("[OutfitDB] get_outfit error %s: %s", source_code, e)
            return {}
        finally:
            if conn:
                conn.close()

    @classmethod
    def get_outfit_by_occasion(cls, source_code: str, occasion_tag: str) -> dict[str, list]:
        """Lấy outfit cho 1 sản phẩm trong 1 dịp cụ thể. Returns {role: [items]}."""
        full = cls.get_outfit(source_code)
        return full.get(occasion_tag, {})

    # ── Stylist Pin/Unpin ──────────────────────────────────────────────────────

    @classmethod
    def pin_item(cls, item_id: int, is_pinned: bool = True) -> bool:
        """Stylist ghim/bỏ ghim 1 item cụ thể."""
        cls.ensure_tables()
        conn = None
        try:
            conn = _get_conn()
            cur = conn.cursor()
            pin_val = 1 if (USE_SQLITE and is_pinned) else is_pinned
            placeholder = "?" if USE_SQLITE else "%s"
            cur.execute(
                f"UPDATE {_ITEMS} SET is_pinned = {placeholder} WHERE id = {placeholder}",
                (pin_val, item_id),
            )
            updated = cur.rowcount > 0
            conn.commit()
            if not USE_SQLITE:
                cur.close()
            return updated
        except Exception as e:
            logger.error("[OutfitDB] pin_item error id=%s: %s", item_id, e)
            return False
        finally:
            if conn:
                conn.close()

    # ── Stats ──────────────────────────────────────────────────────────────────

    @classmethod
    def get_stats(cls) -> dict:
        """Số lượng set + items đang lưu."""
        cls.ensure_tables()
        conn = None
        try:
            conn = _get_conn()
            cur = conn.cursor()
            cur.execute(f"SELECT COUNT(*) FROM {_SET}")
            sets_count = cur.fetchone()[0]
            cur.execute(f"SELECT COUNT(*) FROM {_ITEMS}")
            items_count = cur.fetchone()[0]
            if not USE_SQLITE:
                cur.close()
            return {"outfit_sets": sets_count, "outfit_items": items_count}
        except Exception as e:
            logger.error("[OutfitDB] get_stats error: %s", e)
            return {}
        finally:
            if conn:
                conn.close()


# ─── Auto-init on import ──────────────────────────────────────────────────────
try:
    OutfitDB.ensure_tables()
except Exception:
    pass
