#!/bin/bash
# backfill-proofs.sh - Generate/upgrade OpenTimestamp proofs for all commits
# Usage: backfill-proofs.sh [repository-path]

set -e

REPO_PATH="${1:-.}"
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

cd "$REPO_PATH"

# Verify we're in a git repository
if ! git rev-parse --git-dir > /dev/null 2>&1; then
    echo "Error: not a git repository" >&2
    exit 1
fi

# Find the generate-proof.sh script
GENERATE_SCRIPT=""

# Check if generate-proof.sh is in the same directory as this script
if [ -f "$SCRIPT_DIR/generate-proof.sh" ]; then
    GENERATE_SCRIPT="$SCRIPT_DIR/generate-proof.sh"
# Check in repository root
elif [ -f "generate-proof.sh" ]; then
    GENERATE_SCRIPT="./generate-proof.sh"
# Check if skill is installed globally
elif [ -f "$HOME/.openclaw/workspace/skills/git-ots-hook/scripts/generate-proof.sh" ]; then
    GENERATE_SCRIPT="$HOME/.openclaw/workspace/skills/git-ots-hook/scripts/generate-proof.sh"
else
    echo "Error: generate-proof.sh not found" >&2
    exit 1
fi

chmod +x "$GENERATE_SCRIPT"

# Ensure .ots directory exists
mkdir -p .ots

echo "[ots-backfill] Scanning commit history..."

# Get all commit hashes (oldest to newest)
COMMITS=$(git rev-list --reverse HEAD)
TOTAL=$(echo "$COMMITS" | wc -l)
CURRENT=0

# Track if any proofs were updated
UPDATED=0

for COMMIT in $COMMITS; do
    CURRENT=$((CURRENT + 1))
    echo "[ots-backfill] Processing commit $CURRENT/$TOTAL: ${COMMIT:0:8}"
    
    # Check if proof exists for this commit
    PROOF_FILE=".ots/${COMMIT}.ots"
    
    if [ -f "$PROOF_FILE" ]; then
        # Try to upgrade existing proof
        echo "  Upgrading existing proof..."
        if ots upgrade "$PROOF_FILE" 2>/dev/null; then
            echo "  ✓ Upgraded to attested"
            UPDATED=$((UPDATED + 1))
        else
            echo "  - Still pending (no upgrade available)"
        fi
    else
        # Generate new proof for this commit
        echo "  Generating new proof..."
        "$GENERATE_SCRIPT" "$COMMIT" "$PROOF_FILE" >/dev/null 2>&1
        echo "  ✓ Generated proof"
        UPDATED=$((UPDATED + 1))
    fi
done

# Create/update latest proof symlink
LATEST_COMMIT=$(git rev-parse HEAD)
if [ -f ".ots/${LATEST_COMMIT}.ots" ]; then
    cp ".ots/${LATEST_COMMIT}.ots" ".ots/proof.ots"
    echo "[ots-backfill] Updated .ots/proof.ots for latest commit"
fi

# Save previous commit chain info
echo "[ots-backfill] Saving commit chain..."
git rev-list HEAD | while read COMMIT; do
    PREV=$(git rev-parse ${COMMIT}^1 2>/dev/null || echo "")
    if [ -n "$PREV" ]; then
        echo "$COMMIT:$PREV" >> ".ots/commit-chain.txt"
    fi
done

echo ""
echo "[ots-backfill] Complete! Processed $TOTAL commits, updated $UPDATED proofs"
echo ""
echo "Proofs stored in: .ots/"
echo "  - Individual proofs: .ots/<commit-hash>.ots"
echo "  - Latest proof: .ots/proof.ots"
echo "  - Commit chain: .ots/commit-chain.txt"