package main

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

// makeRPCDir creates a webSrcDir with optional lib/query-client.ts for the
// global mutation handler check.
func makeRPCDir(t *testing.T) string {
	t.Helper()
	dir := t.TempDir()
	return dir
}

func writeRPCComponent(t *testing.T, webSrcDir, subpath, content string) {
	t.Helper()
	fullPath := filepath.Join(webSrcDir, subpath)
	if err := os.MkdirAll(filepath.Dir(fullPath), 0755); err != nil {
		t.Fatalf("mkdir %s: %v", filepath.Dir(fullPath), err)
	}
	if err := os.WriteFile(fullPath, []byte(content), 0644); err != nil {
		t.Fatalf("write %s: %v", fullPath, err)
	}
}

func writeGlobalMutationHandler(t *testing.T, webSrcDir string) {
	t.Helper()
	libDir := filepath.Join(webSrcDir, "lib")
	if err := os.MkdirAll(libDir, 0755); err != nil {
		t.Fatalf("mkdir lib: %v", err)
	}
	if err := os.WriteFile(filepath.Join(libDir, "query-client.ts"), []byte(`
import { MutationCache, QueryClient } from '@tanstack/react-query'

export const queryClient = new QueryClient({
  mutationCache: new MutationCache({
    onError: (error) => {
      console.error('Global mutation error', error)
    },
  }),
})
`), 0644); err != nil {
		t.Fatalf("write query-client.ts: %v", err)
	}
}

// ─────────────────────────────────────────────
// checkRPCErrors – query-no-error warning
// ─────────────────────────────────────────────

func TestCheckRPCErrors_QueryWithoutError_Warning(t *testing.T) {
	dir := makeRPCDir(t)
	writeRPCComponent(t, dir, "components/my-component.tsx", `
import { useQuery } from '@block-ninja/api/queries'

export function MyComponent() {
  const { data, isLoading } = useQuery(myQuery, {})
  return <div>{data}</div>
}
`)

	violations, warnings := checkRPCErrors(dir)
	if len(warnings) == 0 {
		t.Fatal("expected at least 1 warning for useQuery without error destructuring")
	}
	found := false
	for _, w := range warnings {
		if w.rule == "query-no-error" {
			found = true
		}
	}
	if !found {
		t.Fatalf("expected rule 'query-no-error' in warnings, got: %#v", warnings)
	}
	// Should not be a hard violation
	if len(violations) != 0 {
		t.Fatalf("expected 0 hard violations for missing query error, got %d: %#v", len(violations), violations)
	}
}

func TestCheckRPCErrors_QueryWithError_NoWarning(t *testing.T) {
	dir := makeRPCDir(t)
	writeRPCComponent(t, dir, "components/my-component.tsx", `
import { useQuery } from '@block-ninja/api/queries'

export function MyComponent() {
  const { data, isLoading, error } = useQuery(myQuery, {})
  if (error) return <div>Error!</div>
  return <div>{data}</div>
}
`)

	_, warnings := checkRPCErrors(dir)
	if len(warnings) != 0 {
		t.Fatalf("expected 0 warnings when error is destructured, got %d: %#v", len(warnings), warnings)
	}
}

// ─────────────────────────────────────────────
// checkRPCErrors – mutation-no-error-handler violation
// ─────────────────────────────────────────────

func TestCheckRPCErrors_MutationWithNoErrorHandler_Violation(t *testing.T) {
	dir := makeRPCDir(t)
	// No global handler, no onError, no try/catch, no toast.error
	writeRPCComponent(t, dir, "components/editor.tsx", `
import { useMutation } from '@block-ninja/api/queries'

export function Editor() {
  const saveMutation = useMutation(saveBlock)

  function handleSave() {
    saveMutation.mutate({ content: 'hello' })
  }

  return <button onClick={handleSave}>Save</button>
}
`)

	violations, _ := checkRPCErrors(dir)
	if len(violations) == 0 {
		t.Fatal("expected violation for mutation without error handler")
	}
	found := false
	for _, v := range violations {
		if v.rule == "mutation-no-error-handler" {
			found = true
		}
	}
	if !found {
		t.Fatalf("expected rule 'mutation-no-error-handler', got: %#v", violations)
	}
}

func TestCheckRPCErrors_MutationWithOnError_Clean(t *testing.T) {
	dir := makeRPCDir(t)
	writeRPCComponent(t, dir, "components/editor.tsx", `
import { useMutation } from '@block-ninja/api/queries'
import { toast } from 'sonner'

export function Editor() {
  const saveMutation = useMutation(saveBlock, {
    onError: (err) => toast.error('Save failed', { description: err.message }),
    onSuccess: () => toast.success('Saved'),
  })

  return <button onClick={() => saveMutation.mutate({})}>Save</button>
}
`)

	violations, _ := checkRPCErrors(dir)
	if len(violations) != 0 {
		t.Fatalf("expected 0 violations for mutation with onError, got %d: %#v", len(violations), violations)
	}
}

func TestCheckRPCErrors_MutationWithTryCatch_Clean(t *testing.T) {
	dir := makeRPCDir(t)
	writeRPCComponent(t, dir, "components/editor.tsx", `
import { useMutation } from '@block-ninja/api/queries'

export function Editor() {
  const saveMutation = useMutation(saveBlock)

  async function handleSave() {
    try {
      await saveMutation.mutateAsync({})
    } catch (err) {
      console.error(err)
    }
  }

  return <button onClick={handleSave}>Save</button>
}
`)

	violations, _ := checkRPCErrors(dir)
	if len(violations) != 0 {
		t.Fatalf("expected 0 violations when try/catch is present, got %d: %#v", len(violations), violations)
	}
}

func TestCheckRPCErrors_MutationWithToastError_Clean(t *testing.T) {
	dir := makeRPCDir(t)
	writeRPCComponent(t, dir, "components/editor.tsx", `
import { useMutation } from '@block-ninja/api/queries'
import { toast } from 'sonner'

export function Editor() {
  const saveMutation = useMutation(saveBlock)

  function handleSave() {
    saveMutation.mutate({}, {
      onSuccess: () => toast.success('Done'),
    })
    // fallback: toast.error happens elsewhere
  }

  function handleError(err) {
    toast.error('Failed: ' + err.message)
  }

  return <button onClick={handleSave}>Save</button>
}
`)

	violations, _ := checkRPCErrors(dir)
	if len(violations) != 0 {
		t.Fatalf("expected 0 violations when toast.error is present in file, got %d: %#v", len(violations), violations)
	}
}

func TestCheckRPCErrors_GlobalHandlerSuppressesViolation(t *testing.T) {
	dir := makeRPCDir(t)
	writeGlobalMutationHandler(t, dir)

	// Mutation with no per-mutation error handling — suppressed by global handler
	writeRPCComponent(t, dir, "components/editor.tsx", `
import { useMutation } from '@block-ninja/api/queries'

export function Editor() {
  const saveMutation = useMutation(saveBlock)
  return <button onClick={() => saveMutation.mutate({})}>Save</button>
}
`)

	violations, _ := checkRPCErrors(dir)
	if len(violations) != 0 {
		t.Fatalf("expected 0 violations when global mutation handler is present, got %d: %#v", len(violations), violations)
	}
}

// ─────────────────────────────────────────────
// checkRPCErrors – file path scoping
// ─────────────────────────────────────────────

func TestCheckRPCErrors_SkipsFilesOutsideComponentsAndRoutes(t *testing.T) {
	dir := makeRPCDir(t)
	// File is in lib/ — not components/ or routes/, should be skipped
	writeRPCComponent(t, dir, "lib/utils.tsx", `
import { useMutation } from '@block-ninja/api/queries'

export function useHelperMutation() {
  return useMutation(doSomething)
}
`)

	violations, warnings := checkRPCErrors(dir)
	if len(violations) != 0 || len(warnings) != 0 {
		t.Fatalf("expected 0 violations and 0 warnings for file outside scoped dirs, got v=%d w=%d",
			len(violations), len(warnings))
	}
}

func TestCheckRPCErrors_ChecksRouteFiles(t *testing.T) {
	dir := makeRPCDir(t)
	// File in routes/ should be checked — mutation with no handler
	writeRPCComponent(t, dir, "routes/dashboard.tsx", `
import { useMutation } from '@block-ninja/api/queries'

export function Dashboard() {
  const doThing = useMutation(action)
  return <button onClick={() => doThing.mutate({})}>Go</button>
}
`)

	violations, _ := checkRPCErrors(dir)
	if len(violations) == 0 {
		t.Fatal("expected violation for mutation in routes/ without error handler")
	}
}

// ─────────────────────────────────────────────
// checkRPCErrors – comment lines skipped
// ─────────────────────────────────────────────

func TestCheckRPCErrors_CommentedMutationSkipped(t *testing.T) {
	dir := makeRPCDir(t)
	writeRPCComponent(t, dir, "components/thing.tsx", `
export function Thing() {
  // const doThing = useMutation(action)
  return <div />
}
`)

	violations, _ := checkRPCErrors(dir)
	if len(violations) != 0 {
		t.Fatalf("expected 0 violations for commented-out mutation, got %d: %#v", len(violations), violations)
	}
}

// ─────────────────────────────────────────────
// hasGlobalMutationErrorHandler
// ─────────────────────────────────────────────

func TestHasGlobalMutationErrorHandler_Present(t *testing.T) {
	dir := makeRPCDir(t)
	writeGlobalMutationHandler(t, dir)
	if !hasGlobalMutationErrorHandler(dir) {
		t.Fatal("expected hasGlobalMutationErrorHandler to return true when handler is present")
	}
}

func TestHasGlobalMutationErrorHandler_Missing(t *testing.T) {
	dir := makeRPCDir(t)
	if hasGlobalMutationErrorHandler(dir) {
		t.Fatal("expected hasGlobalMutationErrorHandler to return false when file is absent")
	}
}

func TestHasGlobalMutationErrorHandler_PartialContent(t *testing.T) {
	dir := makeRPCDir(t)
	libDir := filepath.Join(dir, "lib")
	if err := os.MkdirAll(libDir, 0755); err != nil {
		t.Fatalf("mkdir lib: %v", err)
	}
	// Has MutationCache but no onError
	if err := os.WriteFile(filepath.Join(libDir, "query-client.ts"), []byte(`
import { MutationCache } from '@tanstack/react-query'
const cache = new MutationCache({})
`), 0644); err != nil {
		t.Fatalf("write query-client.ts: %v", err)
	}
	if hasGlobalMutationErrorHandler(dir) {
		t.Fatal("expected false when MutationCache present but onError absent")
	}
}