#!/bin/bash

# Configuration
backupPath='/mnt/backups'
password_file="/etc/restic-password"
LOG_DIR="$HOME/mb-backups/logs"
LOG_FILE="${LOG_DIR}/backup_sessions.log"
ERROR_LOG_FILE="${LOG_DIR}/backup_sessions_error.log"

# Ensure log directory exists
mkdir -p "$LOG_DIR"

# Logging function
log_message() {
    echo "[$(date +'%Y-%m-%d %H:%M:%S')] $1" | tee -a "$LOG_FILE"
}

# Error logging function
log_error() {
    echo "[$(date +'%Y-%m-%d %H:%M:%S')] ERROR: $1" | tee -a "$ERROR_LOG_FILE"
}

# Function: Display usage
display_usage() {
    echo "Usage: $0 [options]"
    echo ""
    echo "Options:"
    echo "  sessions          - Show all complete backup sessions"
    echo "  incomplete        - Show incomplete backup sessions"
    echo "  all              - Show all snapshots grouped by session"
    echo "  validate <tag>   - Validate a specific backup session"
    echo ""
    echo "Examples:"
    echo "  $0 sessions"
    echo "  $0 validate manual-backup-2024-01-15_10-30-45"
    exit 1
}

# Function: Validate repository access
validate_repository() {
    log_message "Validating repository access..."

    if [ ! -d "$backupPath" ]; then
        log_error "Backup path '$backupPath' does not exist or is not accessible."
        echo "Restic repository path not found. Please verify that the path exists and is mounted."
        exit 1
    fi

    if ! RESTIC_PASSWORD=$(cat "$password_file") restic -r "$backupPath" snapshots &>/dev/null; then
        log_message "Attempting to fix permissions for '$backupPath'..."
        sudo chown -R "$(whoami)":"$(whoami)" "$backupPath" 2>/dev/null || true
        sudo chmod -R u+rwX "$backupPath" 2>/dev/null || true

        if ! RESTIC_PASSWORD=$(cat "$password_file") restic -r "$backupPath" snapshots &>/dev/null; then
            log_error "Unable to access Restic repository at '$backupPath'."
            echo "Restic repository is inaccessible. Please check the path, permissions, or mount status."
            exit 1
        fi
    fi

    log_message "Repository access validated successfully."
}

# Function: Get all snapshots with session analysis
get_all_snapshots() {
    log_message "Retrieving all snapshots for session analysis..."
    
    local snapshots_json
    snapshots_json=$(RESTIC_PASSWORD=$(cat "$password_file") restic -r "$backupPath" snapshots --json 2>/dev/null)
    
    if [ $? -ne 0 ] || [ -z "$snapshots_json" ]; then
        log_error "Failed to retrieve snapshots from repository."
        return 1
    fi
    
    echo "$snapshots_json"
    return 0
}

# Function: Extract backup session tags
extract_session_tags() {
    local snapshots_json="$1"
    
    # Extract all session tags (manual-backup-* and automated-backup-*)
    echo "$snapshots_json" | jq -r '.[].tags[]' | grep -E '^(manual|automated)-backup-[0-9]{4}-[0-9]{2}-[0-9]{2}_[0-9]{2}-[0-9]{2}-[0-9]{2}$' | sort | uniq
}

# Function: Analyze backup session completeness
analyze_session_completeness() {
    local snapshots_json="$1"
    local session_tag="$2"
    
    # Get all snapshots for this session
    local session_snapshots
    session_snapshots=$(echo "$snapshots_json" | jq -r ".[] | select(.tags[] | contains(\"$session_tag\"))")
    
    # Count snapshots in session
    local snapshot_count
    snapshot_count=$(echo "$session_snapshots" | jq -s '. | length')
    
    # Extract component tags
    local has_core=false
    local has_media=false
    local has_db=false
    
    if echo "$session_snapshots" | jq -r '.tags[]' | grep -q "^core_files$"; then
        has_core=true
    fi
    
    if echo "$session_snapshots" | jq -r '.tags[]' | grep -q "^media_themes$"; then
        has_media=true
    fi
    
    if echo "$session_snapshots" | jq -r '.tags[]' | grep -q "^wordpress_db$"; then
        has_db=true
    fi
    
    # Determine session status
    local status="INCOMPLETE"
    local missing_components=()
    
    if [ "$has_core" = true ] && [ "$has_media" = true ] && [ "$has_db" = true ] && [ "$snapshot_count" -eq 3 ]; then
        status="COMPLETE"
    else
        if [ "$has_core" = false ]; then
            missing_components+=("core_files")
        fi
        if [ "$has_media" = false ]; then
            missing_components+=("media_themes")
        fi
        if [ "$has_db" = false ]; then
            missing_components+=("wordpress_db")
        fi
    fi
    
    # Get session timestamp
    local session_time
    session_time=$(echo "$session_snapshots" | jq -r '.time' | head -n1)
    
    # Output session info
    echo "$session_tag|$status|$snapshot_count|$session_time|$(IFS=,; echo "${missing_components[*]}")"
}

# Function: Display complete backup sessions
display_complete_sessions() {
    log_message "Displaying complete backup sessions..."
    
    local snapshots_json
    snapshots_json=$(get_all_snapshots)
    
    if [ $? -ne 0 ]; then
        echo "Failed to retrieve snapshots."
        return 1
    fi
    
    local session_tags
    session_tags=$(extract_session_tags "$snapshots_json")
    
    if [ -z "$session_tags" ]; then
        echo "No backup sessions found."
        return 0
    fi
    
    echo "=== COMPLETE BACKUP SESSIONS ==="
    echo "Format: [Session Tag] [Date/Time] [Status]"
    echo "========================================"
    
    local complete_sessions=0
    
    while IFS= read -r session_tag; do
        if [ -n "$session_tag" ]; then
            local session_info
            session_info=$(analyze_session_completeness "$snapshots_json" "$session_tag")
            
            local status
            status=$(echo "$session_info" | cut -d'|' -f2)
            
            if [ "$status" = "COMPLETE" ]; then
                local session_time
                session_time=$(echo "$session_info" | cut -d'|' -f4)
                
                printf "%-45s %s [%s]\n" "$session_tag" "$session_time" "$status"
                ((complete_sessions++))
            fi
        fi
    done <<< "$session_tags"
    
    echo "========================================"
    echo "Total complete backup sessions: $complete_sessions"
    echo ""
    echo "To restore a complete session, use:"
    echo "  ./restore_full_backup_session.sh <session_tag>"
}

# Function: Display incomplete backup sessions
display_incomplete_sessions() {
    log_message "Displaying incomplete backup sessions..."
    
    local snapshots_json
    snapshots_json=$(get_all_snapshots)
    
    if [ $? -ne 0 ]; then
        echo "Failed to retrieve snapshots."
        return 1
    fi
    
    local session_tags
    session_tags=$(extract_session_tags "$snapshots_json")
    
    if [ -z "$session_tags" ]; then
        echo "No backup sessions found."
        return 0
    fi
    
    echo "=== INCOMPLETE BACKUP SESSIONS ==="
    echo "Format: [Session Tag] [Date/Time] [Status] [Missing Components]"
    echo "================================================================="
    
    local incomplete_sessions=0
    
    while IFS= read -r session_tag; do
        if [ -n "$session_tag" ]; then
            local session_info
            session_info=$(analyze_session_completeness "$snapshots_json" "$session_tag")
            
            local status
            status=$(echo "$session_info" | cut -d'|' -f2)
            
            if [ "$status" = "INCOMPLETE" ]; then
                local session_time missing_components
                session_time=$(echo "$session_info" | cut -d'|' -f4)
                missing_components=$(echo "$session_info" | cut -d'|' -f5)
                
                printf "%-45s %s [%s] Missing: %s\n" "$session_tag" "$session_time" "$status" "$missing_components"
                ((incomplete_sessions++))
            fi
        fi
    done <<< "$session_tags"
    
    echo "================================================================="
    echo "Total incomplete backup sessions: $incomplete_sessions"
    echo ""
    echo "WARNING: Incomplete sessions cannot be used for full restoration."
}

# Function: Display all sessions with details
display_all_sessions() {
    log_message "Displaying all backup sessions with details..."
    
    local snapshots_json
    snapshots_json=$(get_all_snapshots)
    
    if [ $? -ne 0 ]; then
        echo "Failed to retrieve snapshots."
        return 1
    fi
    
    local session_tags
    session_tags=$(extract_session_tags "$snapshots_json")
    
    if [ -z "$session_tags" ]; then
        echo "No backup sessions found."
        return 0
    fi
    
    echo "=== ALL BACKUP SESSIONS ==="
    echo "Format: [Session Tag] [Date/Time] [Status] [Snapshot Count] [Missing Components]"
    echo "============================================================================="
    
    local total_sessions=0
    local complete_sessions=0
    
    while IFS= read -r session_tag; do
        if [ -n "$session_tag" ]; then
            local session_info
            session_info=$(analyze_session_completeness "$snapshots_json" "$session_tag")
            
            local status session_time snapshot_count missing_components
            status=$(echo "$session_info" | cut -d'|' -f2)
            snapshot_count=$(echo "$session_info" | cut -d'|' -f3)
            session_time=$(echo "$session_info" | cut -d'|' -f4)
            missing_components=$(echo "$session_info" | cut -d'|' -f5)
            
            if [ "$status" = "COMPLETE" ]; then
                printf "%-45s %s [%s] (%d snapshots)\n" "$session_tag" "$session_time" "$status" "$snapshot_count"
                ((complete_sessions++))
            else
                printf "%-45s %s [%s] (%d snapshots) Missing: %s\n" "$session_tag" "$session_time" "$status" "$snapshot_count" "$missing_components"
            fi
            
            ((total_sessions++))
        fi
    done <<< "$session_tags"
    
    echo "============================================================================="
    echo "Total sessions: $total_sessions (Complete: $complete_sessions, Incomplete: $((total_sessions - complete_sessions)))"
}

# Function: Validate specific backup session
validate_backup_session() {
    local session_tag="$1"
    
    log_message "Validating backup session: $session_tag"
    
    # Validate session tag format
    if [[ ! "$session_tag" =~ ^(manual|automated)-backup-[0-9]{4}-[0-9]{2}-[0-9]{2}_[0-9]{2}-[0-9]{2}-[0-9]{2}$ ]]; then
        echo "ERROR: Invalid backup session tag format."
        echo "Expected format: manual-backup-YYYY-MM-DD_HH-MM-SS or automated-backup-YYYY-MM-DD_HH-MM-SS"
        return 1
    fi
    
    local snapshots_json
    snapshots_json=$(get_all_snapshots)
    
    if [ $? -ne 0 ]; then
        echo "Failed to retrieve snapshots."
        return 1
    fi
    
    # Check if session exists
    local session_snapshots
    session_snapshots=$(echo "$snapshots_json" | jq -r ".[] | select(.tags[] | contains(\"$session_tag\"))")
    
    if [ -z "$session_snapshots" ]; then
        echo "ERROR: No snapshots found for session tag '$session_tag'."
        return 1
    fi
    
    # Analyze session
    local session_info
    session_info=$(analyze_session_completeness "$snapshots_json" "$session_tag")
    
    local status snapshot_count session_time missing_components
    status=$(echo "$session_info" | cut -d'|' -f2)
    snapshot_count=$(echo "$session_info" | cut -d'|' -f3)
    session_time=$(echo "$session_info" | cut -d'|' -f4)
    missing_components=$(echo "$session_info" | cut -d'|' -f5)
    
    echo "=== BACKUP SESSION VALIDATION ==="
    echo "Session Tag: $session_tag"
    echo "Session Time: $session_time"
    echo "Status: $status"
    echo "Snapshot Count: $snapshot_count"
    
    if [ "$status" = "COMPLETE" ]; then
        echo "✓ All required components present:"
        echo "  ✓ Core Files (core_files)"
        echo "  ✓ Media Files (media_themes)"
        echo "  ✓ Database (wordpress_db)"
        echo ""
        echo "This session is ready for full restoration using:"
        echo "  ./restore_full_backup_session.sh $session_tag"
    else
        echo "✗ Session is incomplete. Missing components:"
        IFS=',' read -ra MISSING <<< "$missing_components"
        for component in "${MISSING[@]}"; do
            echo "  ✗ $component"
        done
        echo ""
        echo "WARNING: This session cannot be used for full restoration."
    fi
    
    echo "================================="
    
    # Show individual snapshots in session
    echo ""
    echo "Individual snapshots in this session:"
    echo "$session_snapshots" | jq -r '"  " + .short_id + " - " + .time + " - Tags: " + (.tags | join(", "))'
}

# Function: Validate environment
validate_environment() {
    if [ ! -f "$password_file" ]; then
        log_error "Password file not found at $password_file"
        exit 1
    fi

    validate_repository
}

# Main script logic
main() {
    local action="${1:-sessions}"
    
    case "$action" in
        "sessions")
            validate_environment
            display_complete_sessions
            ;;
        "incomplete")
            validate_environment
            display_incomplete_sessions
            ;;
        "all")
            validate_environment
            display_all_sessions
            ;;
        "validate")
            if [ -z "$2" ]; then
                echo "ERROR: Session tag required for validation."
                echo "Usage: $0 validate <session_tag>"
                exit 1
            fi
            validate_environment
            validate_backup_session "$2"
            ;;
        *)
            display_usage
            ;;
    esac
}

# Run main function
main "$@"