package simulations

import io.gatling.core.Predef._
import io.gatling.http.Predef._
import scala.concurrent.duration._

class ApiLoadSimulation extends Simulation {

  // HTTP Protocol Configuration
  val httpProtocol = http
    .baseUrl("https://api.example.com")
    .acceptHeader("application/json")
    .contentTypeHeader("application/json")
    .userAgentHeader("Gatling/LoadTest")
    .shareConnections
    .maxConnectionsPerHost(10)

  // Test Data Feeder
  val userFeeder = csv("users.csv").circular
  val searchFeeder = jsonFile("searches.json").random

  // Request Chains
  val authenticate = exec(
    http("Authenticate")
      .post("/auth/login")
      .body(StringBody("""{"username":"${username}","password":"${password}"}"""))
      .check(
        status.is(200),
        jsonPath("$.token").saveAs("authToken"),
        responseTimeInMillis.lte(500)
      )
  )

  val searchProducts = exec(
    http("Search Products")
      .get("/products/search")
      .queryParam("q", "${searchTerm}")
      .header("Authorization", "Bearer ${authToken}")
      .check(
        status.is(200),
        jsonPath("$.results[*]").count.gte(1),
        responseTimeInMillis.lte(1000)
      )
  )

  val viewProduct = exec(
    http("View Product")
      .get("/products/${productId}")
      .header("Authorization", "Bearer ${authToken}")
      .check(
        status.is(200),
        jsonPath("$.id").is("${productId}"),
        responseTimeInMillis.lte(300)
      )
  )

  // Scenario Definition
  val userJourney = scenario("User Journey")
    .feed(userFeeder)
    .exec(authenticate)
    .pause(1, 3)
    .feed(searchFeeder)
    .exec(searchProducts)
    .pause(500.milliseconds, 2.seconds)
    .repeat(3) {
      exec(viewProduct)
        .pause(1, 2)
    }

  // Load Profile
  setUp(
    userJourney.inject(
      rampUsers(100).during(60.seconds),
      constantUsersPerSec(50).during(300.seconds),
      rampUsersPerSec(50).to(100).during(120.seconds)
    )
  ).protocols(httpProtocol)
    .assertions(
      global.responseTime.percentile3.lt(1000),
      global.successfulRequests.percent.gte(99),
      forAll.failedRequests.percent.lt(1)
    )
}

// Ramp-up load pattern
setUp(
  scenario.inject(
    rampUsers(1000).during(10.minutes)
  )
)

// Constant load with warm-up
setUp(
  scenario.inject(
    nothingFor(5.seconds),
    atOnceUsers(10),
    rampUsers(100).during(1.minute),
    constantUsersPerSec(50).during(5.minutes)
  )
)

// Stress test pattern
setUp(
  scenario.inject(
    incrementUsersPerSec(10)
      .times(5)
      .eachLevelLasting(2.minutes)
      .separatedByRampsLasting(30.seconds)
      .startingFrom(10)
  )
)

// Spike test pattern
setUp(
  scenario.inject(
    constantUsersPerSec(20).during(2.minutes),
    stressPeakUsers(500).during(30.seconds),
    constantUsersPerSec(20).during(2.minutes)
  )
)

// Soak/Endurance test
setUp(
  scenario.inject(
    rampUsersPerSec(1).to(30).during(5.minutes),
    constantUsersPerSec(30).during(4.hours)
  )
)

// CSV Feeder
val csvFeeder = csv("data/users.csv").circular

// JSON Feeder
val jsonFeeder = jsonFile("data/products.json").random

// JDBC Feeder
val jdbcFeeder = jdbcFeeder(
  "jdbc:postgresql://localhost:5432/testdb",
  "postgres", "password",
  "SELECT id, email FROM users WHERE active = true"
)

// Custom Feeder
val customFeeder = Iterator.continually(Map(
  "orderId" -> java.util.UUID.randomUUID().toString,
  "timestamp" -> System.currentTimeMillis(),
  "amount" -> (100 + scala.util.Random.nextInt(900))
))

// Batch Feeder with transformation
val transformedFeeder = csv("data/raw.csv")
  .transform { case (key, value) =>
    if (key == "amount") (value.toDouble * 1.1).toString else value
  }
  .batch(100)
  .random

// Extract and reuse values
exec(
  http("Get CSRF Token")
    .get("/form")
    .check(
      css("input[name='csrf']", "value").saveAs("csrfToken")
    )
)
.exec(
  http("Submit Form")
    .post("/submit")
    .formParam("csrf", "${csrfToken}")
    .formParam("data", "${userData}")
)

// JSON path extraction
exec(
  http("Get Order")
    .get("/orders/${orderId}")
    .check(
      jsonPath("$.items[*].id").findAll.saveAs("itemIds"),
      jsonPath("$.total").saveAs("orderTotal")
    )
)
.foreach("${itemIds}", "itemId") {
  exec(
    http("Get Item Details")
      .get("/items/${itemId}")
  )
}

// Conditional execution
exec(session => {
  if (session("userType").as[String] == "premium") {
    session.set("rateLimit", 1000)
  } else {
    session.set("rateLimit", 100)
  }
})
.doIf("${userType}", "premium") {
  exec(premiumFeatures)
}

setUp(scenario.inject(/* ... */))
  .protocols(httpProtocol)
  .assertions(
    // Global assertions
    global.responseTime.max.lt(5000),
    global.responseTime.mean.lt(500),
    global.responseTime.percentile1.lt(200),  // P50
    global.responseTime.percentile2.lt(500),  // P75
    global.responseTime.percentile3.lt(1000), // P95
    global.responseTime.percentile4.lt(2000), // P99

    // Success rate assertions
    global.successfulRequests.percent.gte(99.5),
    global.failedRequests.count.lt(100),

    // Request-specific assertions
    details("Authenticate").responseTime.percentile3.lt(500),
    details("Search Products").successfulRequests.percent.gte(99),

    // Throughput assertions
    global.requestsPerSec.gte(1000)
  )

// Report configuration
.protocols(httpProtocol)
.pauses(constantPauses)

// Custom report naming
System.setProperty("gatling.core.outputDirectoryBaseName", "api-load-test")
System.setProperty("gatling.charting.indicators.lowerBound", "800")
System.setProperty("gatling.charting.indicators.higherBound", "1200")

{
  "operation": "run-simulation",
  "status": "completed",
  "simulation": {
    "name": "ApiLoadSimulation",
    "duration": "300s",
    "totalUsers": 5000
  },
  "results": {
    "requestCount": 150000,
    "errorCount": 45,
    "errorRate": "0.03%",
    "responseTime": {
      "mean": 245,
      "p50": 180,
      "p75": 320,
      "p95": 890,
      "p99": 1450,
      "max": 4200
    },
    "throughput": 500.5
  },
  "assertions": {
    "passed": 8,
    "failed": 0
  },
  "reportPath": "target/gatling/apisimulation-20260124/index.html"
}