#!/bin/bash
set -e

SYNC_DIR="${SYNC_DIR:-$HOME/.hermes-sync}"
HERMES_HOME="${HERMES_HOME:-$HOME/.hermes}"
HOSTNAME=$(hostname)
cd "$SYNC_DIR"

echo "[$(date '+%H:%M:%S')] Sync from $HOSTNAME..."

# ── Step 1: Export local state.db → state_<hostname>.db ──────────────────
python3 << PYEOF
import sqlite3, os, shutil

local_db = os.path.join(os.environ['HERMES_HOME'], 'state.db')
export_db = os.path.join(os.environ['SYNC_DIR'], f"state_{os.environ['HOSTNAME']}.db")

# Checkpoint WAL
try:
    conn = sqlite3.connect(local_db)
    conn.execute('PRAGMA wal_checkpoint(TRUNCATE)')
    conn.execute('PRAGMA optimize')
    conn.close()
except Exception as e:
    print(f'Checkpoint: {e}', file=__import__('sys').stderr)

shutil.copy2(local_db, export_db)
print(f'Exported: {export_db}')
PYEOF

# ── Step 2: Git stage ────────────────────────────────────────────────────
git add -A
HAS_LOCAL=false
if ! git diff --cached --quiet || ! git diff --quiet; then
    HAS_LOCAL=true
fi

# ── Step 3: Fetch + merge ─────────────────────────────────────────────────
git fetch origin main

if git rev-parse HEAD >/dev/null 2>&1 && \
   git rev-parse origin/main >/dev/null 2>&1 && \
   ! git merge-base --is-ancestor HEAD origin/main 2>/dev/null; then
    echo "Merging remote..."
    if [ "$HAS_LOCAL" = true ]; then
        git stash push -m "local $(date)" 2>/dev/null || true
        if ! git merge origin/main --no-edit 2>/dev/null; then
            git checkout --ours sync.sh memories/MEMORY.md 2>/dev/null || true
            git add -A
            git commit -m "Auto-resolve $(date)" 2>/dev/null || true
        fi
        if git stash list | grep -q "local "; then
            git stash pop 2>/dev/null || true
            git rebase origin/main 2>/dev/null || {
                git rebase --abort 2>/dev/null || true
                git merge origin/main --no-edit 2>/dev/null || true
            }
        fi
    else
        git merge origin/main --no-edit 2>/dev/null || \
        git merge --ff-only origin/main 2>/dev/null || \
        git reset --hard origin/main
    fi
fi

# ── Step 4: Merge all state_*.db → state_merged.db ──────────────────────
python3 << 'PYEOF'
import sqlite3, os, glob, shutil

sync_dir = os.environ['SYNC_DIR']
hermes_home = os.environ['HERMES_HOME']
merged_path = os.path.join(sync_dir, 'state_merged.db')
db_files = sorted(glob.glob(os.path.join(sync_dir, 'state_*.db')))
db_files = [f for f in db_files if not f.endswith('_merged.db')]
print(f'DBs to merge: {[os.path.basename(f) for f in db_files]}')

if os.path.exists(merged_path):
    os.remove(merged_path)

def get_schema(conn, table):
    cols = conn.execute(f'PRAGMA table_info("{table}")').fetchall()
    return [c[1] for c in cols]  # column names

def copy_table(src_conn, dst_conn, table):
    cols = get_schema(src_conn, table)
    placeholders = ','.join(['?'] * len(cols))
    col_names = ','.join(f'"{c}"' for c in cols)
    
    rows = src_conn.execute(f'SELECT {col_names} FROM "{table}"').fetchall()
    for row in rows:
        dst_conn.execute(f'INSERT OR REPLACE INTO "{table}" ({col_names}) VALUES ({placeholders})', row)
    return len(rows)

# Open merged DB and rebuild from scratch
conn_merged = sqlite3.connect(merged_path)
conn_merged.execute('PRAGMA journal_mode=WAL')
conn_merged.execute('PRAGMA synchronous=NORMAL')

# We need at least one source to initialize schema
if not db_files:
    print('No state DBs found, creating empty merged DB')
    conn_merged.execute('''
    CREATE TABLE IF NOT EXISTS sessions (
        id TEXT PRIMARY KEY, source TEXT NOT NULL, user_id TEXT,
        model TEXT, model_config TEXT, system_prompt TEXT,
        parent_session_id TEXT, started_at REAL, ended_at REAL,
        end_reason TEXT, message_count INTEGER DEFAULT 0,
        tool_call_count INTEGER DEFAULT 0, input_tokens INTEGER DEFAULT 0,
        output_tokens INTEGER DEFAULT 0, cache_read_tokens INTEGER DEFAULT 0,
        cache_write_tokens INTEGER DEFAULT 0, reasoning_tokens INTEGER DEFAULT 0,
        billing_provider TEXT, billing_base_url TEXT, billing_mode TEXT,
        estimated_cost_usd REAL, actual_cost_usd REAL,
        cost_status TEXT, cost_source TEXT, pricing_version TEXT, title TEXT
    )''')
    conn_merged.execute('''
    CREATE TABLE IF NOT EXISTS messages (
        id INTEGER PRIMARY KEY,
        session_id TEXT NOT NULL, role TEXT NOT NULL, content TEXT,
        tool_call_id TEXT, tool_calls TEXT, tool_name TEXT,
        timestamp REAL NOT NULL, token_count INTEGER,
        finish_reason TEXT, reasoning TEXT, reasoning_details TEXT,
        codex_reasoning_items TEXT
    )''')
    conn_merged.commit()
else:
    first_db = db_files[0]
    src_conn = sqlite3.connect(first_db)
    src_conn.execute('PRAGMA wal_checkpoint(TRUNCATE)')
    
    for table in ['sessions', 'messages']:
        cols = get_schema(src_conn, table)
        col_defs = []
        for c in cols:
            if c == 'id' and table == 'messages':
                col_defs.append('id INTEGER PRIMARY KEY')
            elif c == 'id':
                col_defs.append(f'{c} TEXT PRIMARY KEY')
            else:
                col_defs.append(f'{c} TEXT')
        
        conn_merged.execute(f'DROP TABLE IF EXISTS "{table}"')
        conn_merged.execute(f'CREATE TABLE "{table}" ({", ".join(col_defs)})')
        
        placeholders = ','.join(['?'] * len(cols))
        col_names = ','.join(f'"{c}"' for c in cols)
        rows = src_conn.execute(f'SELECT {col_names} FROM "{table}"').fetchall()
        for row in rows:
            conn_merged.execute(f'INSERT OR REPLACE INTO "{table}" ({col_names}) VALUES ({placeholders})', row)
        print(f'  {os.path.basename(first_db)}.{table}: {len(rows)} rows')

    src_conn.close()

conn_merged.execute('PRAGMA wal_checkpoint(TRUNCATE)')
conn_merged.commit()
conn_merged.close()

print(f'Merged: {merged_path} ({os.path.getsize(merged_path)/1024:.0f} KB)')
PYEOF

# ── Step 5: Push ─────────────────────────────────────────────────────────
if [ "$HAS_LOCAL" = true ]; then
    git commit -m "Sync $(date '+%Y-%m-%d %H:%M')" 2>/dev/null || true
    if ! git push origin main 2>&1; then
        echo "Push rejected, pulling..."
        git pull origin main --no-edit 2>/dev/null || true
        git push origin main 2>&1 || echo "Push failed"
    fi
else
    echo "No local changes"
fi

# ── Step 6: Restore merged state to local hermes ─────────────────────────
python3 << 'PYEOF'
import sqlite3, os, shutil

sync_dir = os.environ['SYNC_DIR']
hermes_home = os.environ['HERMES_HOME']
merged_path = os.path.join(sync_dir, 'state_merged.db')
local_db = os.path.join(hermes_home, 'state.db')

if not os.path.exists(merged_path):
    print('No merged DB, skipping restore')
else:
    # Checkpoint + close local
    try:
        conn = sqlite3.connect(local_db)
        conn.execute('PRAGMA wal_checkpoint(TRUNCATE)')
        conn.execute('PRAGMA optimize')
        conn.close()
    except Exception as e:
        print(f'Local checkpoint: {e}')
    
    # Backup
    shutil.copy2(local_db, local_db + '.pre_sync_bak')
    
    # Replace with merged
    shutil.copy2(merged_path, local_db)
    print(f'Restored merged state to {local_db}')
    
    # Remove backup after successful restore
    bak = local_db + '.pre_sync_bak'
    if os.path.exists(bak):
        os.remove(bak)
PYEOF

# ── Step 7: Sync memories + skills (additive) ────────────────────────────
cp "$SYNC_DIR/memories/MEMORY.md" "$HERMES_HOME/memories/MEMORY.md" 2>/dev/null || true
if [ -d "$SYNC_DIR/skills" ]; then
    mkdir -p "$HERMES_HOME/skills"
    rsync -a --ignore-existing "$SYNC_DIR/skills/" "$HERMES_HOME/skills/" 2>/dev/null || \
        cp -rn "$SYNC_DIR/skills/"* "$HERMES_HOME/skills/" 2>/dev/null || true
fi

echo "[$(date '+%H:%M:%S')] Done"