# art-celery/database.py
"""
PostgreSQL database module for Art DAG L1 server.

Provides connection pooling and CRUD operations for cache metadata.
"""

import os
from datetime import datetime, timezone
from typing import List, Optional

import asyncpg

DATABASE_URL = os.getenv("DATABASE_URL", "postgresql://artdag:artdag@localhost:5432/artdag")

pool: Optional[asyncpg.Pool] = None

SCHEMA_SQL = """
-- Core cache: just content hash and IPFS CID
CREATE TABLE IF NOT EXISTS cache_items (
    content_hash VARCHAR(64) PRIMARY KEY,
    ipfs_cid VARCHAR(128),
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

-- Item types: metadata lives here (same item can be recipe AND media)
CREATE TABLE IF NOT EXISTS item_types (
    id SERIAL PRIMARY KEY,
    content_hash VARCHAR(64) REFERENCES cache_items(content_hash) ON DELETE CASCADE,
    type VARCHAR(50) NOT NULL,
    path VARCHAR(255),
    description TEXT,
    source_type VARCHAR(20),
    source_url TEXT,
    source_note TEXT,
    pinned BOOLEAN DEFAULT FALSE,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    UNIQUE(content_hash, type, path)
);

-- Pin reasons: one-to-many from item_types
CREATE TABLE IF NOT EXISTS pin_reasons (
    id SERIAL PRIMARY KEY,
    item_type_id INTEGER REFERENCES item_types(id) ON DELETE CASCADE,
    reason VARCHAR(100) NOT NULL,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

-- L2 shares: includes content_type for role when shared
CREATE TABLE IF NOT EXISTS l2_shares (
    id SERIAL PRIMARY KEY,
    content_hash VARCHAR(64) REFERENCES cache_items(content_hash) ON DELETE CASCADE,
    l2_server VARCHAR(255) NOT NULL,
    asset_name VARCHAR(255) NOT NULL,
    content_type VARCHAR(50) NOT NULL,
    published_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    last_synced_at TIMESTAMP WITH TIME ZONE,
    UNIQUE(content_hash, l2_server, content_type)
);

-- Indexes
CREATE INDEX IF NOT EXISTS idx_item_types_content_hash ON item_types(content_hash);
CREATE INDEX IF NOT EXISTS idx_item_types_type ON item_types(type);
CREATE INDEX IF NOT EXISTS idx_item_types_path ON item_types(path);
CREATE INDEX IF NOT EXISTS idx_pin_reasons_item_type ON pin_reasons(item_type_id);
CREATE INDEX IF NOT EXISTS idx_l2_shares_content_hash ON l2_shares(content_hash);
"""


async def init_db():
    """Initialize database connection pool and create schema."""
    global pool
    pool = await asyncpg.create_pool(DATABASE_URL)
    async with pool.acquire() as conn:
        await conn.execute(SCHEMA_SQL)


async def close_db():
    """Close database connection pool."""
    global pool
    if pool:
        await pool.close()
        pool = None


# ============ Cache Items ============

async def create_cache_item(content_hash: str, ipfs_cid: Optional[str] = None) -> dict:
    """Create a cache item. Returns the created item."""
    async with pool.acquire() as conn:
        row = await conn.fetchrow(
            """
            INSERT INTO cache_items (content_hash, ipfs_cid)
            VALUES ($1, $2)
            ON CONFLICT (content_hash) DO UPDATE SET ipfs_cid = COALESCE($2, cache_items.ipfs_cid)
            RETURNING content_hash, ipfs_cid, created_at
            """,
            content_hash, ipfs_cid
        )
        return dict(row)


async def get_cache_item(content_hash: str) -> Optional[dict]:
    """Get a cache item by content hash."""
    async with pool.acquire() as conn:
        row = await conn.fetchrow(
            "SELECT content_hash, ipfs_cid, created_at FROM cache_items WHERE content_hash = $1",
            content_hash
        )
        return dict(row) if row else None


async def update_cache_item_ipfs_cid(content_hash: str, ipfs_cid: str) -> bool:
    """Update the IPFS CID for a cache item."""
    async with pool.acquire() as conn:
        result = await conn.execute(
            "UPDATE cache_items SET ipfs_cid = $2 WHERE content_hash = $1",
            content_hash, ipfs_cid
        )
        return result == "UPDATE 1"


async def delete_cache_item(content_hash: str) -> bool:
    """Delete a cache item and all associated data (cascades)."""
    async with pool.acquire() as conn:
        result = await conn.execute(
            "DELETE FROM cache_items WHERE content_hash = $1",
            content_hash
        )
        return result == "DELETE 1"


async def list_cache_items(limit: int = 100, offset: int = 0) -> List[dict]:
    """List cache items with pagination."""
    async with pool.acquire() as conn:
        rows = await conn.fetch(
            """
            SELECT content_hash, ipfs_cid, created_at
            FROM cache_items
            ORDER BY created_at DESC
            LIMIT $1 OFFSET $2
            """,
            limit, offset
        )
        return [dict(row) for row in rows]


# ============ Item Types ============

async def add_item_type(
    content_hash: str,
    item_type: str,
    path: Optional[str] = None,
    description: Optional[str] = None,
    source_type: Optional[str] = None,
    source_url: Optional[str] = None,
    source_note: Optional[str] = None,
) -> dict:
    """Add a type to a cache item. Creates cache_item if needed."""
    async with pool.acquire() as conn:
        # Ensure cache_item exists
        await conn.execute(
            "INSERT INTO cache_items (content_hash) VALUES ($1) ON CONFLICT DO NOTHING",
            content_hash
        )
        # Insert or update item_type
        row = await conn.fetchrow(
            """
            INSERT INTO item_types (content_hash, type, path, description, source_type, source_url, source_note)
            VALUES ($1, $2, $3, $4, $5, $6, $7)
            ON CONFLICT (content_hash, type, path) DO UPDATE SET
                description = COALESCE($4, item_types.description),
                source_type = COALESCE($5, item_types.source_type),
                source_url = COALESCE($6, item_types.source_url),
                source_note = COALESCE($7, item_types.source_note)
            RETURNING id, content_hash, type, path, description, source_type, source_url, source_note, pinned, created_at
            """,
            content_hash, item_type, path, description, source_type, source_url, source_note
        )
        return dict(row)


async def get_item_types(content_hash: str) -> List[dict]:
    """Get all types for a cache item."""
    async with pool.acquire() as conn:
        rows = await conn.fetch(
            """
            SELECT id, content_hash, type, path, description, source_type, source_url, source_note, pinned, created_at
            FROM item_types
            WHERE content_hash = $1
            ORDER BY created_at
            """,
            content_hash
        )
        return [dict(row) for row in rows]


async def get_item_type(content_hash: str, item_type: str, path: Optional[str] = None) -> Optional[dict]:
    """Get a specific type for a cache item."""
    async with pool.acquire() as conn:
        if path is None:
            row = await conn.fetchrow(
                """
                SELECT id, content_hash, type, path, description, source_type, source_url, source_note, pinned, created_at
                FROM item_types
                WHERE content_hash = $1 AND type = $2 AND path IS NULL
                """,
                content_hash, item_type
            )
        else:
            row = await conn.fetchrow(
                """
                SELECT id, content_hash, type, path, description, source_type, source_url, source_note, pinned, created_at
                FROM item_types
                WHERE content_hash = $1 AND type = $2 AND path = $3
                """,
                content_hash, item_type, path
            )
        return dict(row) if row else None


async def update_item_type(
    item_type_id: int,
    description: Optional[str] = None,
    source_type: Optional[str] = None,
    source_url: Optional[str] = None,
    source_note: Optional[str] = None,
) -> bool:
    """Update an item type's metadata."""
    async with pool.acquire() as conn:
        result = await conn.execute(
            """
            UPDATE item_types SET
                description = COALESCE($2, description),
                source_type = COALESCE($3, source_type),
                source_url = COALESCE($4, source_url),
                source_note = COALESCE($5, source_note)
            WHERE id = $1
            """,
            item_type_id, description, source_type, source_url, source_note
        )
        return result == "UPDATE 1"


async def delete_item_type(content_hash: str, item_type: str, path: Optional[str] = None) -> bool:
    """Delete a specific type from a cache item."""
    async with pool.acquire() as conn:
        if path is None:
            result = await conn.execute(
                "DELETE FROM item_types WHERE content_hash = $1 AND type = $2 AND path IS NULL",
                content_hash, item_type
            )
        else:
            result = await conn.execute(
                "DELETE FROM item_types WHERE content_hash = $1 AND type = $2 AND path = $3",
                content_hash, item_type, path
            )
        return result == "DELETE 1"


async def list_items_by_type(item_type: str, limit: int = 100, offset: int = 0) -> List[dict]:
    """List all items of a specific type."""
    async with pool.acquire() as conn:
        rows = await conn.fetch(
            """
            SELECT it.id, it.content_hash, it.type, it.path, it.description,
                   it.source_type, it.source_url, it.source_note, it.pinned, it.created_at,
                   ci.ipfs_cid
            FROM item_types it
            JOIN cache_items ci ON it.content_hash = ci.content_hash
            WHERE it.type = $1
            ORDER BY it.created_at DESC
            LIMIT $2 OFFSET $3
            """,
            item_type, limit, offset
        )
        return [dict(row) for row in rows]


async def get_item_by_path(item_type: str, path: str) -> Optional[dict]:
    """Get an item by its type and path (e.g., recipe:/effects/dog)."""
    async with pool.acquire() as conn:
        row = await conn.fetchrow(
            """
            SELECT it.id, it.content_hash, it.type, it.path, it.description,
                   it.source_type, it.source_url, it.source_note, it.pinned, it.created_at,
                   ci.ipfs_cid
            FROM item_types it
            JOIN cache_items ci ON it.content_hash = ci.content_hash
            WHERE it.type = $1 AND it.path = $2
            """,
            item_type, path
        )
        return dict(row) if row else None


# ============ Pinning ============

async def pin_item_type(item_type_id: int, reason: str) -> bool:
    """Pin an item type with a reason."""
    async with pool.acquire() as conn:
        async with conn.transaction():
            # Set pinned flag
            await conn.execute(
                "UPDATE item_types SET pinned = TRUE WHERE id = $1",
                item_type_id
            )
            # Add pin reason
            await conn.execute(
                "INSERT INTO pin_reasons (item_type_id, reason) VALUES ($1, $2)",
                item_type_id, reason
            )
        return True


async def unpin_item_type(item_type_id: int, reason: Optional[str] = None) -> bool:
    """Remove a pin reason from an item type. If no reasons left, unpins the item."""
    async with pool.acquire() as conn:
        async with conn.transaction():
            if reason:
                # Remove specific reason
                await conn.execute(
                    "DELETE FROM pin_reasons WHERE item_type_id = $1 AND reason = $2",
                    item_type_id, reason
                )
            else:
                # Remove all reasons
                await conn.execute(
                    "DELETE FROM pin_reasons WHERE item_type_id = $1",
                    item_type_id
                )

            # Check if any reasons remain
            count = await conn.fetchval(
                "SELECT COUNT(*) FROM pin_reasons WHERE item_type_id = $1",
                item_type_id
            )

            if count == 0:
                await conn.execute(
                    "UPDATE item_types SET pinned = FALSE WHERE id = $1",
                    item_type_id
                )
        return True


async def get_pin_reasons(item_type_id: int) -> List[dict]:
    """Get all pin reasons for an item type."""
    async with pool.acquire() as conn:
        rows = await conn.fetch(
            "SELECT id, reason, created_at FROM pin_reasons WHERE item_type_id = $1 ORDER BY created_at",
            item_type_id
        )
        return [dict(row) for row in rows]


async def is_item_pinned(content_hash: str, item_type: Optional[str] = None) -> tuple[bool, List[str]]:
    """Check if any type of a cache item is pinned. Returns (is_pinned, reasons)."""
    async with pool.acquire() as conn:
        if item_type:
            rows = await conn.fetch(
                """
                SELECT pr.reason
                FROM pin_reasons pr
                JOIN item_types it ON pr.item_type_id = it.id
                WHERE it.content_hash = $1 AND it.type = $2 AND it.pinned = TRUE
                """,
                content_hash, item_type
            )
        else:
            rows = await conn.fetch(
                """
                SELECT pr.reason
                FROM pin_reasons pr
                JOIN item_types it ON pr.item_type_id = it.id
                WHERE it.content_hash = $1 AND it.pinned = TRUE
                """,
                content_hash
            )
        reasons = [row["reason"] for row in rows]
        return len(reasons) > 0, reasons


# ============ L2 Shares ============

async def add_l2_share(
    content_hash: str,
    l2_server: str,
    asset_name: str,
    content_type: str,
) -> dict:
    """Add or update an L2 share."""
    async with pool.acquire() as conn:
        row = await conn.fetchrow(
            """
            INSERT INTO l2_shares (content_hash, l2_server, asset_name, content_type, last_synced_at)
            VALUES ($1, $2, $3, $4, NOW())
            ON CONFLICT (content_hash, l2_server, content_type) DO UPDATE SET
                asset_name = $3,
                last_synced_at = NOW()
            RETURNING id, content_hash, l2_server, asset_name, content_type, published_at, last_synced_at
            """,
            content_hash, l2_server, asset_name, content_type
        )
        return dict(row)


async def get_l2_shares(content_hash: str) -> List[dict]:
    """Get all L2 shares for a cache item."""
    async with pool.acquire() as conn:
        rows = await conn.fetch(
            """
            SELECT id, content_hash, l2_server, asset_name, content_type, published_at, last_synced_at
            FROM l2_shares
            WHERE content_hash = $1
            ORDER BY published_at
            """,
            content_hash
        )
        return [dict(row) for row in rows]


async def delete_l2_share(content_hash: str, l2_server: str, content_type: str) -> bool:
    """Delete an L2 share."""
    async with pool.acquire() as conn:
        result = await conn.execute(
            "DELETE FROM l2_shares WHERE content_hash = $1 AND l2_server = $2 AND content_type = $3",
            content_hash, l2_server, content_type
        )
        return result == "DELETE 1"