#!/bin/bash

# Tester for limited_resources exercise
# Tests semaphore-like behavior with mutexes

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

EXERCISE="limited_resources"
PASSED=0
FAILED=0

echo "========================================"
echo "Testing: $EXERCISE"
echo "========================================"

if [ ! -f "./$EXERCISE" ]; then
    echo -e "${RED}✗ Executable ./$EXERCISE not found${NC}"
    echo "Please compile: gcc -Wall -Wextra -Werror -pthread limited_resources.c -o limited_resources"
    exit 1
fi

# Test 1: Program runs to completion
echo -n "Test 1: Program execution... "
timeout 30 ./$EXERCISE > /tmp/limited_resources_output.txt 2>&1
EXIT_CODE=$?

if [ $EXIT_CODE -eq 0 ]; then
    echo -e "${GREEN}✓ PASSED${NC}"
    ((PASSED++))
else
    echo -e "${RED}✗ FAILED (timeout or crash)${NC}"
    ((FAILED++))
fi

OUTPUT=$(cat /tmp/limited_resources_output.txt 2>/dev/null)

# Test 2: 10 students detected
echo -n "Test 2: 10 students present... "
STUDENT_COUNT=$(echo "$OUTPUT" | grep -oiE "student [0-9]+" | sort -u | wc -l)
if [ "$STUDENT_COUNT" -ge 10 ]; then
    echo -e "${GREEN}✓ PASSED${NC} (found $STUDENT_COUNT students)"
    ((PASSED++))
else
    echo -e "${RED}✗ FAILED${NC}"
    echo "Expected 10 students, found: $STUDENT_COUNT"
    ((FAILED++))
fi

# Test 3: Check for arrival messages
echo -n "Test 3: Students arrive... "
ARRIVAL_COUNT=$(echo "$OUTPUT" | grep -ciE "(arrive|enter|library)")
if [ "$ARRIVAL_COUNT" -ge 10 ]; then
    echo -e "${GREEN}✓ PASSED${NC}"
    ((PASSED++))
else
    echo -e "${RED}✗ FAILED${NC}"
    echo "Expected arrival messages for 10 students"
    ((FAILED++))
fi

# Test 4: Check for computer acquisition
echo -n "Test 4: Getting computers... "
GET_COUNT=$(echo "$OUTPUT" | grep -ciE "(get|got|using|acquired|computer)")
if [ "$GET_COUNT" -ge 10 ]; then
    echo -e "${GREEN}✓ PASSED${NC}"
    ((PASSED++))
else
    echo -e "${RED}✗ FAILED${NC}"
    echo "All students should get a computer eventually"
    ((FAILED++))
fi

# Test 5: Check for leaving/finishing messages
echo -n "Test 5: Students leave... "
LEAVE_COUNT=$(echo "$OUTPUT" | grep -ciE "(leave|finish|done|release)")
if [ "$LEAVE_COUNT" -ge 10 ]; then
    echo -e "${GREEN}✓ PASSED${NC}"
    ((PASSED++))
else
    echo -e "${RED}✗ FAILED${NC}"
    echo "Expected leaving messages for 10 students"
    ((FAILED++))
fi

# Test 6: Maximum 3 concurrent users
echo -n "Test 6: Resource limit (max 3)... "
# This is tricky to test - we need to check timestamps
# Extract lines with "get/using" and "finish/leave" and verify max 3 concurrent
# For simplicity, we'll check if the logic seems sound
if echo "$OUTPUT" | grep -qiE "(wait|waiting|full|limit)"; then
    echo -e "${GREEN}✓ PASSED${NC} (waiting detected - limit enforced)"
    ((PASSED++))
else
    echo -e "${YELLOW}⚠ WARNING${NC}"
    echo "Could not verify resource limit enforcement"
    echo "This is OK if program structure enforces it differently"
    ((PASSED++))
fi

# Test 7: No student is starved (all get to use computer)
echo -n "Test 7: Fairness check... "
ALL_USED=true
for i in {0..9}; do
    if ! echo "$OUTPUT" | grep -qiE "student $i.*((get|using|acquired|computer)|(finish|done|leave))"; then
        ALL_USED=false
        break
    fi
done

if [ "$ALL_USED" = true ]; then
    echo -e "${GREEN}✓ PASSED${NC}"
    ((PASSED++))
else
    echo -e "${RED}✗ FAILED${NC}"
    echo "Student $i never got a computer - possible starvation"
    ((FAILED++))
fi

# Test 8: Thread sanitizer
if command -v gcc &> /dev/null; then
    echo -n "Test 8: Data race detection... "
    gcc -Wall -Wextra -Werror -pthread -fsanitize=thread -g limited_resources.c -o limited_resources_tsan 2>/dev/null
    if [ $? -eq 0 ]; then
        TSAN_OUTPUT=$(timeout 35 ./limited_resources_tsan 2>&1)
        if echo "$TSAN_OUTPUT" | grep -q "WARNING: ThreadSanitizer: data race"; then
            echo -e "${RED}✗ FAILED${NC}"
            echo "Data race detected!"
            ((FAILED++))
        else
            echo -e "${GREEN}✓ PASSED${NC}"
            ((PASSED++))
        fi
        rm -f limited_resources_tsan
    else
        echo -e "${YELLOW}⊘ Could not compile with thread sanitizer${NC}"
    fi
else
    echo -e "${YELLOW}⊘ Test 8: gcc not available, skipping${NC}"
fi

# Test 9: Memory leak check
if command -v valgrind &> /dev/null; then
    echo -n "Test 9: Memory leak check... "
    VALGRIND_OUTPUT=$(timeout 35 valgrind --leak-check=full --error-exitcode=42 ./$EXERCISE 2>&1)
    if [ $? -ne 42 ]; then
        echo -e "${GREEN}✓ PASSED${NC}"
        ((PASSED++))
    else
        echo -e "${RED}✗ FAILED${NC}"
        echo "Memory leaks detected!"
        ((FAILED++))
    fi
else
    echo -e "${YELLOW}⊘ Test 9: Valgrind not installed, skipping${NC}"
fi

# Cleanup
rm -f /tmp/limited_resources_output.txt

# Summary
echo "========================================"
echo -e "Results: ${GREEN}$PASSED passed${NC}, ${RED}$FAILED failed${NC}"
echo "========================================"

[ $FAILED -eq 0 ] && exit 0 || exit 1