package main

import (
  "os"
  "path/filepath"
  "testing"
)

// TestServeShardsPruneUnreferencedExternalEndpoints verifies an external leaf
// leaves both resident endpoint indexes when its last owning edge disappears.
func TestServeShardsPruneUnreferencedExternalEndpoints(t *testing.T) {
  root := t.TempDir()
  writeGraphFile(t, filepath.Join(root, "tsconfig.json"), `{
  "compilerOptions": { "target": "ES2022", "module": "commonjs", "strict": true },
  "include": ["src"]
}`)
  writeGraphFile(t, filepath.Join(root, "src", "api.d.ts"), "export declare function external(): number;\n")
  index := filepath.Join(root, "src", "index.ts")
  writeGraphFile(t, index, "import { external } from './api';\nexport function run(): number { return external(); }\n")

  session, err := newGraphSession(root, "tsconfig.json")
  if err != nil {
    t.Fatal(err)
  }
  defer session.Close()
  if snapshot, _, _, err := session.SnapshotShards(); err != nil || snapshot == nil {
    t.Fatalf("initial shard snapshot = snapshot:%v error:%v", snapshot != nil, err)
  }
  source := session.compiler.Program().SourceFile(index)
  if source == nil {
    t.Fatal("fixture source was absent from resident program")
  }
  sourceKey := session.graphStore.sourceKeys[source.FileName()]
  var externalID string
  for id := range session.graphStore.sourceExternal[sourceKey] {
    externalID = id
    break
  }
  if externalID == "" {
    t.Fatal("fixture did not produce an external endpoint")
  }

  if err := os.WriteFile(index, []byte("import { external } from './api';\nexport function run(): number { return 1; }\n"), 0o644); err != nil {
    t.Fatal(err)
  }
  snapshot, mode, changed, err := session.SnapshotShards()
  if err != nil {
    t.Fatal(err)
  }
  if snapshot == nil || mode != serveModeIncremental || !changed {
    t.Fatalf("external endpoint edit = snapshot:%v mode:%q changed:%v", snapshot != nil, mode, changed)
  }
  if session.graphStore.externalReferences[externalID] != 0 {
    t.Fatalf("external endpoint %s retained a reference count", externalID)
  }
  if _, exists := session.graphStore.externalNodes[externalID]; exists {
    t.Fatalf("external endpoint %s remained in the wire endpoint cache", externalID)
  }
  for id, node := range session.graphStore.nodes {
    if node.External {
      t.Fatalf("external endpoint %s remained in the internal endpoint cache as %s", externalID, id)
    }
  }
  assertServeShardFactsMatchFullDump(t, session)
}