#!/bin/bash

# Tester for precise_timing exercise
# Tests timing functions accuracy

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

EXERCISE="precise_timing"
EXE_PATH=""
PASSED=0
FAILED=0

# Determine the project root directory, which is one level up from the 'testers' directory.
PROJECT_ROOT=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)

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

# --- Find or compile the executable ---
# Priority:
# 1. rendu/executable
# 2. root/executable
# 3. rendu/source -> compile
# 4. root/source -> compile

# Define potential paths for executable and source
EXE_IN_RENDU="$PROJECT_ROOT/rendu/$EXERCISE"
EXE_IN_ROOT="$PROJECT_ROOT/$EXERCISE"
SRC_IN_RENDU="$PROJECT_ROOT/rendu/${EXERCISE}.c"
SRC_IN_ROOT="$PROJECT_ROOT/${EXERCISE}.c"

# Check for existing executable
if [ -f "$EXE_IN_RENDU" ]; then
    EXE_PATH="$EXE_IN_RENDU"
    echo -e "${YELLOW}Found executable in 'rendu' directory.${NC}"
elif [ -f "$EXE_IN_ROOT" ]; then
    EXE_PATH="$EXE_IN_ROOT"
    echo -e "${YELLOW}Found executable in root directory.${NC}"
else
    echo -e "${YELLOW}Executable not found. Attempting to compile from source...${NC}"
    COMPILE_CMD="gcc -Wall -Wextra -Werror -pthread"

    # Check for source file and compile
    if [ -f "$SRC_IN_RENDU" ]; then
        echo "Found source file in 'rendu'. Compiling..."
        if $COMPILE_CMD "$SRC_IN_RENDU" -o "$EXE_IN_RENDU"; then
            EXE_PATH="$EXE_IN_RENDU"
            echo -e "${GREEN}Compilation successful.${NC}"
        else
            echo -e "${RED}✗ Compilation failed for '$SRC_IN_RENDU'.${NC}"
            exit 1
        fi
    elif [ -f "$SRC_IN_ROOT" ]; then
        echo "Found source file in root. Compiling..."
        if $COMPILE_CMD "$SRC_IN_ROOT" -o "$EXE_IN_ROOT"; then
            EXE_PATH="$EXE_IN_ROOT"
            echo -e "${GREEN}Compilation successful.${NC}"
        else
            echo -e "${RED}✗ Compilation failed for '$SRC_IN_ROOT'.${NC}"
            exit 1
        fi
    else
        echo -e "${RED}✗ Neither executable nor source file found for '$EXERCISE'.${NC}"
        echo "Looked for:"
        echo "  - $EXE_IN_RENDU"
        echo "  - $EXE_IN_ROOT"
        echo "  - $SRC_IN_RENDU"
        echo "  - $SRC_IN_ROOT"
        exit 1
    fi
fi

echo -e "${YELLOW}Using executable at: $EXE_PATH${NC}"

# Test 1: Basic execution
echo -n "Test 1: Program runs successfully... "
OUTPUT=$(timeout 5 "$EXE_PATH" 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

# Test 2: Check if time difference is approximately 100ms
echo -n "Test 2: Sleep precision (~100ms)... "
OUTPUT=$(timeout 5 "$EXE_PATH" 2>&1)
# Extract number that should be around 100
TIME_DIFF=$(echo "$OUTPUT" | grep -oP "\d+" | tail -1)

if [ -n "$TIME_DIFF" ]; then
    # Allow 5ms margin of error (95-105ms is acceptable)
    if [ "$TIME_DIFF" -ge 95 ] && [ "$TIME_DIFF" -le 105 ]; then
        echo -e "${GREEN}✓ PASSED${NC} (measured: ${TIME_DIFF}ms)"
        ((PASSED++))
    elif [ "$TIME_DIFF" -ge 90 ] && [ "$TIME_DIFF" -le 110 ]; then
        echo -e "${YELLOW}⚠ PARTIAL${NC} (measured: ${TIME_DIFF}ms, acceptable but not ideal)"
        ((PASSED++))
    else
        echo -e "${RED}✗ FAILED${NC}"
        echo "Expected ~100ms, got: ${TIME_DIFF}ms"
        echo "Output: $OUTPUT"
        ((FAILED++))
    fi
else
    echo -e "${RED}✗ FAILED${NC}"
    echo "Could not extract time difference from output"
    echo "Output: $OUTPUT"
    ((FAILED++))
fi

# Test 3: Consistency across multiple runs
echo -n "Test 3: Timing consistency (5 runs)... "
CONSISTENT=true
TOTAL=0
COUNT=0

for i in {1..5}; do
    OUTPUT=$(timeout 5 "$EXE_PATH" 2>&1)
    TIME_DIFF=$(echo "$OUTPUT" | grep -oP "\d+" | tail -1)
    
    if [ -n "$TIME_DIFF" ]; then
        TOTAL=$((TOTAL + TIME_DIFF))
        COUNT=$((COUNT + 1))
        
        if [ "$TIME_DIFF" -lt 90 ] || [ "$TIME_DIFF" -gt 110 ]; then
            CONSISTENT=false
        fi
    fi
done

if [ "$CONSISTENT" = true ] && [ "$COUNT" -eq 5 ]; then
    AVG=$((TOTAL / COUNT))
    echo -e "${GREEN}✓ PASSED${NC} (avg: ${AVG}ms)"
    ((PASSED++))
else
    echo -e "${RED}✗ FAILED${NC}"
    if [ "$COUNT" -eq 5 ]; then
        AVG=$((TOTAL / COUNT))
        echo "Timing inconsistent across runs (avg: ${AVG}ms)"
    else
        echo "Some runs failed to complete"
    fi
    ((FAILED++))
fi

# Test 4: Check output format
echo -n "Test 4: Output format check... "
OUTPUT=$(timeout 5 "$EXE_PATH" 2>&1)
if echo "$OUTPUT" | grep -qE "Time difference: [0-9]+ ms"; then
    echo -e "${GREEN}✓ PASSED${NC}"
    ((PASSED++))
else
    echo -e "${RED}✗ FAILED${NC}"
    echo "Expected output format: 'Time difference: <number> ms'"
    echo "Got: $OUTPUT"
    ((FAILED++))
fi

# Test 5: Check for memory leaks with valgrind
if command -v valgrind &> /dev/null; then
    echo -n "Test 5: Memory leak check... "
    VALGRIND_OUTPUT=$(valgrind --leak-check=full --error-exitcode=42 "$EXE_PATH" 2>&1)
    if [ $? -ne 42 ]; then
        echo -e "${GREEN}✓ PASSED${NC}"
        ((PASSED++))
    else
        echo -e "${RED}✗ FAILED${NC}"
        echo "Memory leaks detected!"
        echo "$VALGRIND_OUTPUT" | grep -A 5 "LEAK SUMMARY"
        ((FAILED++))
    fi
else
    echo -e "${YELLOW}⊘ Test 5: Valgrind not installed, skipping memory test${NC}"
fi


# Final summary
echo "----------------------------------------"
if [ $FAILED -eq 0 ]; then
    echo -e "${GREEN}Summary: All $PASSED tests passed for $EXERCISE!${NC}"
    exit 0
else
    echo -e "${RED}Summary: $FAILED out of $((PASSED + FAILED)) tests failed for $EXERCISE.${NC}"
    exit 1
fi