#!/bin/bash

# ProjectTracker - Multi-repo scan script
# Scans all tracked repos, pulls updates, generates state.json

set -euo pipefail

# Paths
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_TRACKER="$(cd "$SCRIPT_DIR/.." && pwd)"
CONFIG_FILE="$SCRIPT_DIR/config.json"

# Check jq availability
if ! command -v jq &> /dev/null; then
    echo "ERROR: jq is required but not installed."
    echo "Install: https://stedolan.github.io/jq/download/"
    exit 1
fi

# Load config
REPOS_ROOT=$(jq -r '.repos_root' "$CONFIG_FILE")
LOOKBACK_DAYS=$(jq -r '.scan_options.commits_lookback_days' "$CONFIG_FILE")
AUTO_PULL=$(jq -r '.scan_options.auto_pull' "$CONFIG_FILE")

# Output files
STATE_FILE="$PROJECT_TRACKER/.planning/state.json"
LOG_FILE="$PROJECT_TRACKER/.planning/scan.log"
CONFLICTS_FILE="$PROJECT_TRACKER/.planning/conflicts.txt"

# Ensure .planning exists
mkdir -p "$PROJECT_TRACKER/.planning"

# Init log
echo "===== Scan started: $(date -Iseconds) =====" > "$LOG_FILE"
> "$CONFLICTS_FILE"

echo "🔍 ProjectTracker - Multi-repo scan"
echo "Repos root: $REPOS_ROOT"
echo ""

# Read tracked repos into array
mapfile -t TRACKED_REPOS < <(jq -r '.tracked_repos[]' "$CONFIG_FILE")

# Start building state.json
cat > "$STATE_FILE" << 'EOF_HEADER'
{
  "last_scan": "TIMESTAMP_PLACEHOLDER",
  "repos": {
EOF_HEADER

FIRST_REPO=true
CONFLICT_COUNT=0
SCANNED_COUNT=0
ATTENTION_COUNT=0

# Scan each repo
for repo in "${TRACKED_REPOS[@]}"; do
    REPO_PATH="$REPOS_ROOT/$repo"

    # Check if repo exists
    if [ ! -d "$REPO_PATH/.git" ]; then
        echo "⚠️  $repo - NOT A GIT REPO (skipping)" | tee -a "$LOG_FILE"
        continue
    fi

    echo -n "📂 $repo... " | tee -a "$LOG_FILE"

    cd "$REPO_PATH"

    # Fetch origin
    git fetch origin &>> "$LOG_FILE" || true

    # Pull if enabled
    HAS_CONFLICT=false
    if [ "$AUTO_PULL" = "true" ]; then
        PULL_OUTPUT=$(git pull 2>&1) || true
        echo "$PULL_OUTPUT" >> "$LOG_FILE"

        if echo "$PULL_OUTPUT" | grep -q "CONFLICT\|Automatic merge failed"; then
            HAS_CONFLICT=true
            CONFLICT_COUNT=$((CONFLICT_COUNT + 1))
            echo "⚠️ CONFLICT: $repo" | tee -a "$CONFLICTS_FILE"
        fi
    fi

    # Collect repo info
    CURRENT_COMMIT=$(git rev-parse --short HEAD 2>/dev/null || echo "unknown")
    CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null || echo "unknown")
    LAST_COMMIT_MSG=$(git log -1 --format="%s" 2>/dev/null || echo "No commits")
    LAST_COMMIT_DATE=$(git log -1 --format="%ar" 2>/dev/null || echo "unknown")

    # Ahead/behind tracking branch
    TRACKING_BRANCH=$(git rev-parse --abbrev-ref --symbolic-full-name @{u} 2>/dev/null || echo "")
    if [ -n "$TRACKING_BRANCH" ]; then
        AHEAD=$(git rev-list --count HEAD..$TRACKING_BRANCH 2>/dev/null || echo 0)
        BEHIND=$(git rev-list --count $TRACKING_BRANCH..HEAD 2>/dev/null || echo 0)
    else
        AHEAD=0
        BEHIND=0
    fi

    # Uncommitted changes
    if git diff-index --quiet HEAD -- 2>/dev/null; then
        UNCOMMITTED=false
        UNCOMMITTED_COUNT=0
    else
        UNCOMMITTED=true
        UNCOMMITTED_COUNT=$(git status --short 2>/dev/null | wc -l)
    fi

    # Recent commits
    COMMITS_3W=$(git rev-list --count --since="$LOOKBACK_DAYS days ago" HEAD 2>/dev/null || echo 0)

    # Load previous commit from existing state (if exists)
    PREV_COMMIT=$(jq -r ".repos.\"$repo\".last_commit // \"\"" "$STATE_FILE" 2>/dev/null || echo "")
    if [ -n "$PREV_COMMIT" ] && [ "$PREV_COMMIT" != "$CURRENT_COMMIT" ] && [ "$PREV_COMMIT" != "null" ]; then
        NEW_COMMITS=$(git rev-list --count $PREV_COMMIT..$CURRENT_COMMIT 2>/dev/null || echo 0)
    else
        NEW_COMMITS=0
    fi

    # Determine needs_attention
    NEEDS_ATTENTION=false
    if [ "$NEW_COMMITS" -gt 0 ] || [ "$UNCOMMITTED" = "true" ] || [ "$BEHIND" -gt 0 ] || [ "$HAS_CONFLICT" = "true" ]; then
        NEEDS_ATTENTION=true
        ATTENTION_COUNT=$((ATTENTION_COUNT + 1))
    fi

    # Project file mapping
    PROJECT_FILE=$(jq -r ".project_mapping.\"$repo\" // \"\"" "$CONFIG_FILE")

    # Add comma if not first repo
    if [ "$FIRST_REPO" = false ]; then
        echo "," >> "$STATE_FILE"
    fi
    FIRST_REPO=false

    # Write JSON entry (properly escaped)
    LAST_COMMIT_MSG_ESCAPED=$(echo "$LAST_COMMIT_MSG" | sed 's/\\/\\\\/g; s/"/\\"/g')

    cat >> "$STATE_FILE" << EOF
    "$repo": {
      "last_commit": "$CURRENT_COMMIT",
      "branch": "$CURRENT_BRANCH",
      "last_commit_msg": "$LAST_COMMIT_MSG_ESCAPED",
      "last_commit_date": "$LAST_COMMIT_DATE",
      "commits_3w": $COMMITS_3W,
      "new_commits_since_last_scan": $NEW_COMMITS,
      "ahead": $AHEAD,
      "behind": $BEHIND,
      "has_uncommitted_changes": $UNCOMMITTED,
      "uncommitted_count": $UNCOMMITTED_COUNT,
      "has_conflict": $HAS_CONFLICT,
      "needs_attention": $NEEDS_ATTENTION,
      "project_file": "$PROJECT_FILE"
    }
EOF

    SCANNED_COUNT=$((SCANNED_COUNT + 1))

    # Status indicator
    if [ "$HAS_CONFLICT" = "true" ]; then
        echo "❌ CONFLICT"
    elif [ "$NEEDS_ATTENTION" = "true" ]; then
        echo "⚠️  needs attention"
    else
        echo "✅"
    fi

done

# Close repos object and add stats
cat >> "$STATE_FILE" << EOF
  },
  "stats": {
    "total_repos": $SCANNED_COUNT,
    "active_3w": 0,
    "needs_attention": $ATTENTION_COUNT,
    "conflicts": $CONFLICT_COUNT
  }
}
EOF

# Calculate active repos count
ACTIVE_COUNT=$(jq '[.repos[] | select(.commits_3w > 0)] | length' "$STATE_FILE")
jq ".stats.active_3w = $ACTIVE_COUNT" "$STATE_FILE" > "$STATE_FILE.tmp" && mv "$STATE_FILE.tmp" "$STATE_FILE"

# Update timestamp
TIMESTAMP=$(date -Iseconds)
jq ".last_scan = \"$TIMESTAMP\"" "$STATE_FILE" > "$STATE_FILE.tmp" && mv "$STATE_FILE.tmp" "$STATE_FILE"

# Summary
echo ""
echo "===== Scan completed: $(date -Iseconds) =====" | tee -a "$LOG_FILE"
echo "✅ Scanned: $SCANNED_COUNT repos" | tee -a "$LOG_FILE"
echo "🔥 Active (3w): $ACTIVE_COUNT repos" | tee -a "$LOG_FILE"
echo "⚠️  Needs attention: $ATTENTION_COUNT repos" | tee -a "$LOG_FILE"
echo "❌ Conflicts: $CONFLICT_COUNT repos" | tee -a "$LOG_FILE"
echo ""
echo "📊 State saved to: $STATE_FILE"
echo "📝 Log saved to: $LOG_FILE"

# Generate summary
if [ -f "$SCRIPT_DIR/analyze.py" ]; then
    echo ""
    echo "Generating summary..."
    python3 "$SCRIPT_DIR/analyze.py"
fi