#!/bin/bash
# Script to merge multiple daily Bluesky archive dumps into a single database
# Usage: ./merge_daily_dumps.sh output.db daily_dumps/*.sql.zst

set -e

if [ $# -lt 2 ]; then
    echo "Usage: $0 output.db input1.sql.zst [input2.sql.zst ...]"
    exit 1
fi

OUTPUT_DB="$1"
shift

if [ -f "$OUTPUT_DB" ]; then
    echo "Error: Output database $OUTPUT_DB already exists"
    exit 1
fi

echo "Creating merged database: $OUTPUT_DB"

# Create the database with schema from the first dump
FIRST_DUMP="$1"
echo "Extracting schema from $FIRST_DUMP..."
zstdcat "$FIRST_DUMP" | grep -E "^(CREATE|PRAGMA)" | sqlite3 "$OUTPUT_DB"

# Import all dumps, converting INSERT INTO to INSERT OR IGNORE
# This handles duplicates in hashtags, urls, and users tables
for DUMP in "$@"; do
    echo "Importing $DUMP..."
    zstdcat "$DUMP" | \
        grep -v "^CREATE" | \
        grep -v "^PRAGMA" | \
        sed 's/^INSERT INTO/INSERT OR IGNORE INTO/g' | \
        sqlite3 "$OUTPUT_DB"
done

echo "Rebuilding aggregate statistics..."
sqlite3 "$OUTPUT_DB" <<'EOF'
-- Update use_count for hashtags based on actual usage
UPDATE hashtags SET use_count = (
    SELECT COUNT(*) FROM posts_hashtags WHERE hashtag_id = hashtags.id
);

-- Update use_count for urls based on actual usage
UPDATE urls SET use_count = (
    SELECT COUNT(*) FROM posts_urls WHERE url_id = urls.id
);

-- Update user timestamps to reflect actual data range
UPDATE users SET
    resolved_at = (
        SELECT MIN(timestamp) FROM posts WHERE user_did = users.did
    ),
    updated_at = (
        SELECT MAX(timestamp) FROM posts WHERE user_did = users.did
    );

-- Analyze database for query optimization
ANALYZE;

-- Show summary statistics
SELECT 'Database merge complete!' as status;
SELECT '---' as separator;
SELECT 'Total posts: ' || COUNT(*) FROM posts;
SELECT 'Total users: ' || COUNT(*) FROM users;
SELECT 'Total hashtags: ' || COUNT(*) FROM hashtags;
SELECT 'Total URLs: ' || COUNT(*) FROM urls;
SELECT 'Date range: ' || MIN(timestamp) || ' to ' || MAX(timestamp) FROM posts;
EOF

echo "Merge complete! Database saved to: $OUTPUT_DB"