#!/usr/bin/env bash
#
# UAT Pre-Flight Check: Validate API Readiness
#
# This script checks that all required API endpoints exist and return expected
# responses before running UAT scenarios.
#
# Usage:
#   ./validate_api_readiness.sh [API_URL]
#
# Example:
#   ./validate_api_readiness.sh http://localhost:18180

set -euo pipefail

# Validate required dependencies
for cmd in curl grep; do
    if ! command -v "$cmd" &> /dev/null; then
        echo "ERROR: Required command '$cmd' is not installed."
        exit 1
    fi
done

API_URL="${1:-http://localhost:18180}"
TIMEOUT=5

echo "╔══════════════════════════════════════════════════════════════╗"
echo "║  UAT Pre-Flight Check: API Readiness Validation            ║"
echo "╚══════════════════════════════════════════════════════════════╝"
echo
echo "Target API: $API_URL"
echo "Timeout: ${TIMEOUT}s per check"
echo

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

PASSED=0
FAILED=0
WARNINGS=0

# Helper: Check if endpoint exists and returns expected status
check_endpoint() {
    local method="$1"
    local path="$2"
    local expected_status="$3"
    local description="$4"
    local data="${5:-}"

    echo -n "  [$method $path] $description... "

    if [ "$method" = "GET" ]; then
        response=$(curl -s -w "\n%{http_code}" --max-time "$TIMEOUT" "$API_URL$path" 2>&1 || echo "000")
    else
        response=$(curl -s -w "\n%{http_code}" -X "$method" --max-time "$TIMEOUT" \
            -H "Content-Type: application/json" \
            -d "$data" \
            "$API_URL$path" 2>&1 || echo "000")
    fi

    status=$(echo "$response" | tail -n1)

    if [ "$status" = "$expected_status" ]; then
        echo -e "${GREEN}✓${NC} ($status)"
        ((PASSED++))
        return 0
    elif [ "$status" = "000" ]; then
        echo -e "${RED}✗ Connection failed${NC}"
        ((FAILED++))
        return 1
    else
        echo -e "${YELLOW}⚠ Unexpected status: $status (expected $expected_status)${NC}"
        ((WARNINGS++))
        return 1
    fi
}

# 1. Health Check
echo "1. Basic Connectivity"
check_endpoint "GET" "/v1/health" "200" "Health check endpoint"
echo

# 2. Core API Endpoints
echo "2. Core API Endpoints (UAT Dependencies)"
check_endpoint "GET" "/v1/skeptic?subject=test&predicate=test" "404" "Skeptic query endpoint (expects 404 for empty DB)"
check_endpoint "GET" "/v1/layered?subject=test&predicate=test" "404" "Layered query endpoint (expects 404 for empty DB)"
check_endpoint "GET" "/v1/query?subject=test&predicate=test" "404" "Generic query endpoint (expects 404 for empty DB)"
echo

# 3. Assertion Creation (with invalid data to check endpoint exists)
echo "3. Assertion Creation Endpoint"
invalid_assertion='{"subject":"test","predicate":"test","object":{"type":"Text","value":"test"},"confidence":0.5,"source_class":"Clinical","source_hash":"0000000000000000000000000000000000000000000000000000000000000000","signatures":[]}'

# This should fail validation (empty signatures), but endpoint should exist
echo -n "  [POST /v1/assert] Assertion endpoint... "
response=$(curl -s -w "\n%{http_code}" --max-time "$TIMEOUT" \
    -X POST "$API_URL/v1/assert" \
    -H "Content-Type: application/json" \
    -d "$invalid_assertion" 2>&1 || echo "000")
status=$(echo "$response" | tail -n1)

if [ "$status" = "400" ] || [ "$status" = "201" ]; then
    echo -e "${GREEN}✓${NC} (endpoint exists, got $status)"
    ((PASSED++))
elif [ "$status" = "000" ]; then
    echo -e "${RED}✗ Connection failed${NC}"
    ((FAILED++))
else
    echo -e "${YELLOW}⚠ Unexpected status: $status${NC}"
    ((WARNINGS++))
fi
echo

# 4. OpenAPI Documentation
echo "4. OpenAPI Documentation"
check_endpoint "GET" "/api-docs/openapi.json" "200" "OpenAPI spec"
check_endpoint "GET" "/swagger-ui/index.html" "200" "Swagger UI"
echo

# 5. Required Data Structures (check OpenAPI schema)
echo "5. Data Structure Validation"
echo -n "  Fetching OpenAPI spec... "
openapi=$(curl -s --max-time "$TIMEOUT" "$API_URL/api-docs/openapi.json" 2>/dev/null || echo "{}")
if [ "$openapi" != "{}" ]; then
    echo -e "${GREEN}✓${NC}"
    ((PASSED++))

    # Check for required schemas
    echo -n "  Checking CreateAssertionRequest schema... "
    if echo "$openapi" | grep -q "CreateAssertionRequest"; then
        echo -e "${GREEN}✓${NC}"
        ((PASSED++))
    else
        echo -e "${YELLOW}⚠ Missing${NC}"
        ((WARNINGS++))
    fi

    echo -n "  Checking SkepticResponse schema... "
    if echo "$openapi" | grep -q "SkepticResponse"; then
        echo -e "${GREEN}✓${NC}"
        ((PASSED++))
    else
        echo -e "${YELLOW}⚠ Missing${NC}"
        ((WARNINGS++))
    fi

    echo -n "  Checking LayeredQueryResponse schema... "
    if echo "$openapi" | grep -q "LayeredQueryResponse"; then
        echo -e "${GREEN}✓${NC}"
        ((PASSED++))
    else
        echo -e "${YELLOW}⚠ Missing${NC}"
        ((WARNINGS++))
    fi
else
    echo -e "${RED}✗ Failed to fetch${NC}"
    ((FAILED++))
fi
echo

# 6. Source Class Support
echo "6. Source Class Validation"
echo "  Expected source classes: Regulatory, Clinical, Expert, Crowd, Anecdotal"
echo -n "  Checking via OpenAPI... "
if echo "$openapi" | grep -q "Regulatory"; then
    echo -e "${GREEN}✓${NC}"
    ((PASSED++))
else
    echo -e "${YELLOW}⚠ Source classes not documented${NC}"
    ((WARNINGS++))
fi
echo

# Summary
echo "╔══════════════════════════════════════════════════════════════╗"
echo "║  Summary                                                     ║"
echo "╚══════════════════════════════════════════════════════════════╝"
echo
echo -e "  ${GREEN}Passed:${NC}   $PASSED"
echo -e "  ${YELLOW}Warnings:${NC} $WARNINGS"
echo -e "  ${RED}Failed:${NC}   $FAILED"
echo

if [ "$FAILED" -gt 0 ]; then
    echo -e "${RED}❌ API is NOT ready for UAT execution${NC}"
    echo
    echo "Common issues:"
    echo "  - API server not running (check: cargo run -p stemedb-api)"
    echo "  - Wrong API URL (current: $API_URL)"
    echo "  - Firewall blocking connections"
    echo "  - API still starting up (wait a few seconds and retry)"
    exit 1
elif [ "$WARNINGS" -gt 0 ]; then
    echo -e "${YELLOW}⚠️  API is mostly ready, but some checks failed${NC}"
    echo
    echo "You can proceed with UAT, but some scenarios may fail."
    echo "Review the warnings above."
    exit 0
else
    echo -e "${GREEN}✅ API is READY for UAT execution${NC}"
    echo
    echo "Next steps:"
    echo "  1. Run all UAT scenarios:"
    echo "     STEMEDB_API_URL=$API_URL cargo test --test consumer_health_uat run_all_uat_scenarios -- --ignored --nocapture"
    echo
    echo "  2. Run individual scenarios:"
    echo "     STEMEDB_API_URL=$API_URL cargo test --test consumer_health_uat uat_glp1_muscle_loss_contradiction -- --ignored --nocapture"
    exit 0
fi