Add generate-test-data CLI tool for comprehensive database population with service-based architecture

.gitignore

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+/generate-test-data

cmd/generate-test-data/README.md

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+# Generate Test Data Tool
+
+A comprehensive CLI tool for generating test data in the Mini-Maxit database.
+
+## Features
+
+Generates realistic test data for all database entities:
+- **Users** with different roles (admin, teacher, student)
+- **Groups** with user memberships
+- **Tasks** with test cases and file references
+- **Contests** with tasks, participants, and registrations
+- **Submissions** with results and test outcomes
+- **Supporting tables**: AccessControl, ContestParticipant, ContestParticipantGroup, ContestRegistrationRequests, UserGroup, TestCase, File, LanguageConfig, SubmissionResult, TestResult
+
+## Prerequisites
+
+- PostgreSQL database running
+- File storage service running (optional, can skip connectivity check)
+- Go 1.23+ installed
+- Environment variables configured in `.env` file at project root (automatically loaded)
+  - `JWT_SECRET_KEY` - Required for user password hashing (any string value works for testing)
+
+## Usage
+
+### Basic Usage
+
+```bash
+# Generate default dataset (50 users, 10 groups, 15 tasks, 5 contests)
+# Automatically loads .env from project root
+# Requires JWT_SECRET_KEY environment variable
+go run ./cmd/generate-test-data
+
+# Or set JWT_SECRET_KEY directly
+JWT_SECRET_KEY=your_secret_key go run ./cmd/generate-test-data
+
+# View all available options
+go run ./cmd/generate-test-data --help
+```
+
+**Default Password:** All generated users have the password `password123`
+
+### Common Examples
+
+```bash
+# Large production-like dataset
+go run ./cmd/generate-test-data --users 100 --groups 15 --tasks 30 --contests 10 \
+  --registration-requests-per-contest 10 --collaborators-per-task 3
+
+# Reproducible data for testing
+go run ./cmd/generate-test-data --clear-existing --seed 42 --verbose
+
+# Preview what would be created
+go run ./cmd/generate-test-data --dry-run --users 100 --contests 10
+
+# Skip connectivity checks (for offline testing)
+go run ./cmd/generate-test-data --skip-connectivity-check
+```
+
+## CLI Flags
+
+### User Generation
+- `--users int` - Total number of users (default: 50)
+- `--admin-count int` - Number of admin users (default: 2)
+- `--teacher-count int` - Number of teacher users (default: 8)
+- `--student-count int` - Number of student users (0 = remaining, default: 0)
+- `--user-password string` - Default password for all users (default: "password123")
+
+### Group Generation
+- `--groups int` - Number of groups to create (default: 10)
+- `--users-per-group int` - Average number of users per group (default: 8)
+
+### Task Generation
+- `--tasks int` - Number of tasks to create (default: 15)
+- `--visible-tasks int` - Number of tasks visible to all (default: 10)
+- `--tests-per-task int` - Number of test cases per task (default: 3)
+- `--fixtures-dir string` - Path to fixtures directory (default: "./fixtures")
+- `--create-fixtures` - Create sample fixture files if they don't exist (default: false)
+
+### Contest Generation
+- `--contests int` - Number of contests to create (default: 5)
+- `--tasks-per-contest int` - Number of tasks per contest (default: 5)
+- `--participants-per-contest int` - Individual participants per contest (default: 10)
+- `--group-participants-per-contest int` - Group participants per contest (default: 2)
+
+### Submission Generation
+- `--submissions-per-task int` - Submissions per standalone task (default: 5)
+- `--submissions-per-contest int` - Submissions per contest task (default: 3)
+
+### Supporting Data
+- `--registration-requests-per-contest int` - Registration requests per contest (default: 3)
+- `--collaborators-per-task int` - Collaborators per task via AccessControl (default: 2)
+- `--collaborators-per-contest int` - Collaborators per contest via AccessControl (default: 2)
+
+### Database Configuration
+- `--db-host string` - Database host (overrides DB_HOST env var)
+- `--db-port int` - Database port (overrides DB_PORT env var)
+- `--db-user string` - Database user (overrides DB_USER env var)
+- `--db-password string` - Database password (overrides DB_PASSWORD env var)
+- `--db-name string` - Database name (overrides DB_NAME env var)
+
+### File Storage Configuration
+- `--file-storage-host string` - File storage host (overrides FILE_STORAGE_HOST env var)
+- `--file-storage-port string` - File storage port (overrides FILE_STORAGE_PORT env var)
+
+### Utilities
+- `--clear-existing` - Truncate all tables before generating new data (default: false)
+- `--seed int` - Random seed for reproducible data (0 = time-based, default: 0)
+- `--skip-connectivity-check` - Skip pre-flight connectivity checks (default: false)
+- `--verbose` - Detailed progress output (default: false)
+- `--dry-run` - Show what would be created without actually creating (default: false)
+
+## Pre-flight Checks
+
+Before generating data, the tool verifies:
+1. **Database connectivity** - Tests PostgreSQL connection with `sqlDB.Ping()`
+2. **File storage availability** - Tests file storage HTTP endpoint
+
+If connectivity fails, you'll see clear error messages:
+```
+Error: Database connectivity check failed
+  Host: localhost:5432
+  Error: connection refused
+
+Please ensure PostgreSQL is running and accessible.
+```
+
+Use `--skip-connectivity-check` to bypass these checks if needed.
+
+## Data Generation Order
+
+The tool generates data in dependency order:
+1. LanguageConfig (C, C++, etc.)
+2. Users (with bcrypt-hashed passwords)
+3. Groups → UserGroup (many-to-many relationships)
+4. Tasks → File (descriptions), TestCase → File (test I/O), AccessControl (permissions)
+5. Contests → ContestTask, ContestParticipant, ContestParticipantGroup, ContestRegistrationRequests, AccessControl
+6. Submissions → File (source), SubmissionResult, TestResult → File (stdout/stderr/diff)
+
+## Examples
+
+### Default Development Dataset
+```bash
+go run ./cmd/generate-test-data
+```
+Creates:
+- 50 users (2 admins, 8 teachers, 40 students) - password: `password123`
+- 10 groups with ~8 members each
+- 15 tasks (10 visible) with 3 test cases each
+- 5 contests with 5 tasks and 10 participants each
+- 5 submissions per task
+- Supporting data (access control, registration requests, etc.)
+
+### Large Production-like Dataset
+```bash
+go run ./cmd/generate-test-data \
+  --users 100 \
+  --admin-count 5 \
+  --teacher-count 15 \
+  --groups 10 \
+  --tasks 30 \
+  --contests 10 \
+  --submissions-per-task 10 \
+  --registration-requests-per-contest 10
+```
+
+### Reproducible CI/Testing Data
+```bash
+go run ./cmd/generate-test-data --clear-existing --seed 42 --verbose
+```
+Always generates the same data with seed 42.
+
+### Preview Mode
+```bash
+go run ./cmd/generate-test-data --dry-run --users 100 --contests 10
+```
+Shows configuration without creating any data.
+
+## Troubleshooting
+
+### "Database connectivity check failed"
+- Ensure PostgreSQL is running: `docker-compose up -d postgres`
+- Check DB_HOST, DB_PORT, DB_USER, DB_PASSWORD, DB_NAME environment variables
+- Or use CLI flags: `--db-host localhost --db-port 5432 ...`
+
+### "File storage connectivity check failed"
+- Ensure file-storage service is running: `docker-compose up -d file-storage`
+- Check FILE_STORAGE_HOST and FILE_STORAGE_PORT environment variables
+- Or skip the check: `--skip-connectivity-check`
+
+### "admin + teacher + student counts must equal total users"
+- If you specify --student-count, ensure: admin-count + teacher-count + student-count = users
+- Or set --student-count 0 to auto-calculate remaining
+
+## Development
+
+The tool is built with:
+- **github.com/spf13/cobra** - CLI framework
+- **github.com/brianvoe/gofakeit/v7** - Realistic fake data generation
+- Existing backend repositories and services - Ensures data consistency with API
+
+All generated data follows the same constraints and validation rules as the API.