package cli_test

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"strings"
	"sync"
	"sync/atomic"
	"testing"
	"time"

	"go.uber.org/zap"

	clipkg "iop/apps/node/internal/adapters/cli"
	"iop/apps/node/internal/adapters/cli/internal/testutil"
	noderuntime "iop/apps/node/internal/runtime"
	"iop/packages/config"
)

// opencodeFakeServer is a minimal stand-in for the OpenCode HTTP/SSE server.
// Tests push SSE events through ch; the SSE handler forwards them as
// `data: <json>\n\n` lines until the channel closes.
type opencodeFakeServer struct {
	mu             sync.Mutex
	events         chan map[string]any
	abortCalls     atomic.Int32
	promptCalls    atomic.Int32
	createCalls    atomic.Int32
	lastPromptBody []byte
	createdID      string
}

func newOpencodeFakeServer(t *testing.T, sessionID string) (*opencodeFakeServer, *httptest.Server) {
	t.Helper()
	s := &opencodeFakeServer{
		events:    make(chan map[string]any, 32),
		createdID: sessionID,
	}
	mux := http.NewServeMux()
	eventHandler := func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "text/event-stream")
		w.Header().Set("Cache-Control", "no-cache")
		w.WriteHeader(http.StatusOK)
		flusher, _ := w.(http.Flusher)
		if flusher != nil {
			flusher.Flush()
		}
		for {
			select {
			case <-r.Context().Done():
				return
			case ev, ok := <-s.events:
				if !ok {
					return
				}
				b, err := json.Marshal(ev)
				if err != nil {
					continue
				}
				fmt.Fprintf(w, "data: %s\n\n", string(b))
				if flusher != nil {
					flusher.Flush()
				}
			}
		}
	}
	mux.HandleFunc("/event", eventHandler)
	mux.HandleFunc("/global/event", eventHandler)
	mux.HandleFunc("/session", func(w http.ResponseWriter, r *http.Request) {
		s.createCalls.Add(1)
		w.Header().Set("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(map[string]any{"id": s.createdID})
	})
	mux.HandleFunc("/session/", func(w http.ResponseWriter, r *http.Request) {
		// Routes: /session/{id}/prompt_async or /session/{id}/abort
		path := strings.TrimPrefix(r.URL.Path, "/session/")
		parts := strings.SplitN(path, "/", 2)
		if len(parts) != 2 {
			http.NotFound(w, r)
			return
		}
		switch parts[1] {
		case "prompt_async":
			s.promptCalls.Add(1)
			buf := make([]byte, 4096)
			n, _ := r.Body.Read(buf)
			s.mu.Lock()
			s.lastPromptBody = append([]byte(nil), buf[:n]...)
			s.mu.Unlock()
			w.WriteHeader(http.StatusAccepted)
		case "abort":
			s.abortCalls.Add(1)
			w.WriteHeader(http.StatusOK)
		default:
			http.NotFound(w, r)
		}
	})
	mux.HandleFunc("/permission/", func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	})
	srv := httptest.NewServer(mux)
	t.Cleanup(func() {
		s.mu.Lock()
		if s.events != nil {
			close(s.events)
			s.events = nil
		}
		s.mu.Unlock()
		srv.Close()
	})
	return s, srv
}

func (s *opencodeFakeServer) push(ev map[string]any) {
	s.mu.Lock()
	ch := s.events
	s.mu.Unlock()
	if ch != nil {
		ch <- ev
	}
}

func opencodeGlobalEvent(eventType string, props map[string]any) map[string]any {
	return map[string]any{
		"directory": "/tmp/iop-test",
		"payload": map[string]any{
			"id":         "evt_test",
			"type":       eventType,
			"properties": props,
		},
	}
}

func opencodeSSEProfile(attachURL string, opts ...string) config.CLIProfileConf {
	args := []string{"--attach", attachURL, "--title", "test"}
	args = append(args, opts...)
	return config.CLIProfileConf{
		Command: "/bin/true",
		Args:    args,
		Mode:    "opencode-sse",
	}
}

func TestCLIExecuteOpencodeSSE_StreamsTextDeltas(t *testing.T) {
	fake, srv := newOpencodeFakeServer(t, "ses_1")

	cfg := config.CLIConf{
		Enabled: true,
		Profiles: map[string]config.CLIProfileConf{
			"opencode": opencodeSSEProfile(srv.URL, "--model", "prov/m1", "--dangerously-skip-permissions"),
		},
	}
	c := clipkg.New(cfg, zap.NewNop())
	sink := &testutil.FakeSink{}

	done := make(chan error, 1)
	go func() {
		done <- c.Execute(context.Background(), noderuntime.ExecutionSpec{
			RunID:  "run-1",
			Target: "opencode",
			Input:  map[string]any{"prompt": "hello"},
		}, sink)
	}()

	// Wait until prompt_async has been received, then push events.
	deadline := time.Now().Add(2 * time.Second)
	for fake.promptCalls.Load() == 0 && time.Now().Before(deadline) {
		time.Sleep(5 * time.Millisecond)
	}
	if fake.promptCalls.Load() == 0 {
		t.Fatal("prompt_async was not called")
	}

	fake.push(map[string]any{
		"type": "session.next.text.delta",
		"properties": map[string]any{
			"sessionID": "ses_1",
			"delta":     "Hello ",
		},
	})
	fake.push(map[string]any{
		"type": "session.next.text.delta",
		"properties": map[string]any{
			"sessionID": "ses_1",
			"delta":     "world",
		},
	})
	fake.push(map[string]any{
		"type": "session.next.step.ended",
		"properties": map[string]any{
			"sessionID": "ses_1",
			"tokens":    map[string]any{"input": 5.0, "output": 2.0},
		},
	})
	fake.push(map[string]any{
		"type": "session.idle",
		"properties": map[string]any{
			"sessionID": "ses_1",
		},
	})

	select {
	case err := <-done:
		if err != nil {
			t.Fatalf("execute: %v", err)
		}
	case <-time.After(3 * time.Second):
		t.Fatal("execute did not return")
	}

	events := sink.Events()
	if combined := testutil.CollectDeltas(events); combined != "Hello world" {
		t.Fatalf("deltas: got %q, want %q", combined, "Hello world")
	}
	var complete *noderuntime.RuntimeEvent
	for i := range events {
		if events[i].Type == noderuntime.EventTypeComplete {
			complete = &events[i]
		}
	}
	if complete == nil {
		t.Fatal("expected complete event")
	}
	if complete.Usage == nil || complete.Usage.InputTokens != 5 || complete.Usage.OutputTokens != 2 {
		t.Fatalf("expected usage 5/2, got %+v", complete.Usage)
	}
	if fake.createCalls.Load() != 1 {
		t.Errorf("expected 1 create session call, got %d", fake.createCalls.Load())
	}

	fake.mu.Lock()
	body := append([]byte(nil), fake.lastPromptBody...)
	fake.mu.Unlock()
	var decoded struct {
		Parts []struct {
			Type string `json:"type"`
			Text string `json:"text"`
		} `json:"parts"`
		Model struct {
			ProviderID string `json:"providerID"`
			ModelID    string `json:"modelID"`
		} `json:"model"`
	}
	if err := json.Unmarshal(body, &decoded); err != nil {
		t.Fatalf("decode prompt body: %v (body=%q)", err, string(body))
	}
	if len(decoded.Parts) != 1 || decoded.Parts[0].Type != "text" || decoded.Parts[0].Text != "hello" {
		t.Errorf("parts: got %+v", decoded.Parts)
	}
	if decoded.Model.ProviderID != "prov" || decoded.Model.ModelID != "m1" {
		t.Errorf("model: got %+v", decoded.Model)
	}
}

func TestCLIExecuteOpencodeSSE_GlobalMessagePartDeltaStreamsTextOnly(t *testing.T) {
	fake, srv := newOpencodeFakeServer(t, "ses_global")

	cfg := config.CLIConf{
		Enabled: true,
		Profiles: map[string]config.CLIProfileConf{
			"opencode": opencodeSSEProfile(srv.URL),
		},
	}
	c := clipkg.New(cfg, zap.NewNop())
	sink := &testutil.FakeSink{}

	done := make(chan error, 1)
	go func() {
		done <- c.Execute(context.Background(), noderuntime.ExecutionSpec{
			RunID:  "run-global",
			Target: "opencode",
			Input:  map[string]any{"prompt": "hello"},
		}, sink)
	}()

	deadline := time.Now().Add(2 * time.Second)
	for fake.promptCalls.Load() == 0 && time.Now().Before(deadline) {
		time.Sleep(5 * time.Millisecond)
	}
	if fake.promptCalls.Load() == 0 {
		t.Fatal("prompt_async was not called")
	}

	fake.push(opencodeGlobalEvent("message.part.updated", map[string]any{
		"sessionID": "ses_global",
		"part":      map[string]any{"id": "prt_reason", "type": "reasoning", "text": ""},
	}))
	fake.push(opencodeGlobalEvent("message.part.delta", map[string]any{
		"sessionID": "ses_global",
		"partID":    "prt_reason",
		"field":     "text",
		"delta":     "thinking",
	}))
	fake.push(opencodeGlobalEvent("message.part.updated", map[string]any{
		"sessionID": "ses_global",
		"part":      map[string]any{"id": "prt_text", "type": "text", "text": ""},
	}))
	fake.push(opencodeGlobalEvent("message.part.delta", map[string]any{
		"sessionID": "ses_global",
		"partID":    "prt_text",
		"field":     "text",
		"delta":     "OK",
	}))
	fake.push(opencodeGlobalEvent("message.part.updated", map[string]any{
		"sessionID": "ses_global",
		"part": map[string]any{
			"id":     "prt_finish",
			"type":   "step-finish",
			"tokens": map[string]any{"input": 7.0, "output": 1.0},
		},
	}))
	fake.push(opencodeGlobalEvent("session.status", map[string]any{
		"sessionID": "ses_global",
		"status":    map[string]any{"type": "idle"},
	}))

	select {
	case err := <-done:
		if err != nil {
			t.Fatalf("execute: %v", err)
		}
	case <-time.After(3 * time.Second):
		t.Fatal("execute did not return")
	}

	events := sink.Events()
	if combined := testutil.CollectDeltas(events); combined != "OK" {
		t.Fatalf("deltas: got %q, want %q", combined, "OK")
	}
	var complete *noderuntime.RuntimeEvent
	for i := range events {
		if events[i].Type == noderuntime.EventTypeComplete {
			complete = &events[i]
		}
	}
	if complete == nil {
		t.Fatal("expected complete event")
	}
	if complete.Usage == nil || complete.Usage.InputTokens != 7 || complete.Usage.OutputTokens != 1 {
		t.Fatalf("expected usage 7/1, got %+v", complete.Usage)
	}
}

func TestCLIExecuteOpencodeSSE_PromptAsyncSendsModelObject(t *testing.T) {
	fake, srv := newOpencodeFakeServer(t, "ses_m")

	cfg := config.CLIConf{
		Enabled: true,
		Profiles: map[string]config.CLIProfileConf{
			"opencode": opencodeSSEProfile(srv.URL, "--model", "ollama-dgx/qwen3.6:35b-a3b-bf16"),
		},
	}
	c := clipkg.New(cfg, zap.NewNop())
	sink := &testutil.FakeSink{}

	done := make(chan error, 1)
	go func() {
		done <- c.Execute(context.Background(), noderuntime.ExecutionSpec{
			RunID:  "run-m",
			Target: "opencode",
			Input:  map[string]any{"prompt": "hello"},
		}, sink)
	}()

	deadline := time.Now().Add(2 * time.Second)
	for fake.promptCalls.Load() == 0 && time.Now().Before(deadline) {
		time.Sleep(5 * time.Millisecond)
	}
	if fake.promptCalls.Load() == 0 {
		t.Fatal("prompt_async was not called")
	}
	fake.push(map[string]any{
		"type":       "session.idle",
		"properties": map[string]any{"sessionID": "ses_m"},
	})
	select {
	case err := <-done:
		if err != nil {
			t.Fatalf("execute: %v", err)
		}
	case <-time.After(3 * time.Second):
		t.Fatal("execute did not return")
	}

	fake.mu.Lock()
	body := append([]byte(nil), fake.lastPromptBody...)
	fake.mu.Unlock()
	var decoded struct {
		Model map[string]any `json:"model"`
	}
	if err := json.Unmarshal(body, &decoded); err != nil {
		t.Fatalf("decode body: %v (body=%q)", err, string(body))
	}
	if decoded.Model["providerID"] != "ollama-dgx" {
		t.Errorf("providerID: got %v", decoded.Model["providerID"])
	}
	if decoded.Model["modelID"] != "qwen3.6:35b-a3b-bf16" {
		t.Errorf("modelID: got %v", decoded.Model["modelID"])
	}
}

func TestCLIExecuteOpencodeSSE_InvalidModelEmitsError(t *testing.T) {
	_, srv := newOpencodeFakeServer(t, "ses_bad")

	cfg := config.CLIConf{
		Enabled: true,
		Profiles: map[string]config.CLIProfileConf{
			"opencode": opencodeSSEProfile(srv.URL, "--model", "missing-slash"),
		},
	}
	c := clipkg.New(cfg, zap.NewNop())
	sink := &testutil.FakeSink{}

	err := c.Execute(context.Background(), noderuntime.ExecutionSpec{
		RunID:  "run-bad",
		Target: "opencode",
		Input:  map[string]any{"prompt": "hi"},
	}, sink)
	if err == nil {
		t.Fatal("expected error for invalid model, got nil")
	}
	if !strings.Contains(err.Error(), "missing provider/model separator") {
		t.Fatalf("unexpected error: %v", err)
	}
	var sawErr bool
	for _, e := range sink.Events() {
		if e.Type == noderuntime.EventTypeError && strings.Contains(e.Error, "missing provider/model separator") {
			sawErr = true
		}
	}
	if !sawErr {
		t.Fatal("expected error event with model parse failure")
	}
}

func TestCLIExecuteOpencodeSSE_SessionStatusObjectIdleCompletes(t *testing.T) {
	fake, srv := newOpencodeFakeServer(t, "ses_obj")

	cfg := config.CLIConf{
		Enabled: true,
		Profiles: map[string]config.CLIProfileConf{
			"opencode": opencodeSSEProfile(srv.URL),
		},
	}
	c := clipkg.New(cfg, zap.NewNop())
	sink := &testutil.FakeSink{}

	done := make(chan error, 1)
	go func() {
		done <- c.Execute(context.Background(), noderuntime.ExecutionSpec{
			RunID:  "run-obj",
			Target: "opencode",
			Input:  map[string]any{"prompt": "hi"},
		}, sink)
	}()

	deadline := time.Now().Add(2 * time.Second)
	for fake.promptCalls.Load() == 0 && time.Now().Before(deadline) {
		time.Sleep(5 * time.Millisecond)
	}

	fake.push(map[string]any{
		"type": "session.next.text.delta",
		"properties": map[string]any{
			"sessionID": "ses_obj",
			"delta":     "done",
		},
	})
	fake.push(map[string]any{
		"type": "session.status",
		"properties": map[string]any{
			"sessionID": "ses_obj",
			"status":    map[string]any{"type": "idle"},
		},
	})

	select {
	case err := <-done:
		if err != nil {
			t.Fatalf("execute: %v", err)
		}
	case <-time.After(3 * time.Second):
		t.Fatal("execute did not return")
	}
	var sawComplete bool
	for _, e := range sink.Events() {
		if e.Type == noderuntime.EventTypeComplete {
			sawComplete = true
		}
	}
	if !sawComplete {
		t.Fatal("expected complete event after object-idle session.status")
	}
}

func TestCLIExecuteOpencodeSSE_RequireExistingWithoutSessionErrors(t *testing.T) {
	_, srv := newOpencodeFakeServer(t, "ses_1")

	cfg := config.CLIConf{
		Enabled: true,
		Profiles: map[string]config.CLIProfileConf{
			"opencode": opencodeSSEProfile(srv.URL),
		},
	}
	c := clipkg.New(cfg, zap.NewNop())
	sink := &testutil.FakeSink{}

	err := c.Execute(context.Background(), noderuntime.ExecutionSpec{
		RunID:       "run-x",
		Target:      "opencode",
		SessionID:   "abs",
		SessionMode: noderuntime.SessionModeRequireExisting,
		Input:       map[string]any{"prompt": "hi"},
	}, sink)
	if err == nil {
		t.Fatal("expected error when SessionModeRequireExisting and no cached session")
	}
	if !strings.Contains(err.Error(), "no persistent session") {
		t.Fatalf("unexpected error: %v", err)
	}
}

func TestCLIExecuteOpencodeSSE_SessionErrorEmitsRuntimeError(t *testing.T) {
	fake, srv := newOpencodeFakeServer(t, "ses_1")

	cfg := config.CLIConf{
		Enabled: true,
		Profiles: map[string]config.CLIProfileConf{
			"opencode": opencodeSSEProfile(srv.URL),
		},
	}
	c := clipkg.New(cfg, zap.NewNop())
	sink := &testutil.FakeSink{}

	done := make(chan error, 1)
	go func() {
		done <- c.Execute(context.Background(), noderuntime.ExecutionSpec{
			RunID:  "run-err",
			Target: "opencode",
			Input:  map[string]any{"prompt": "hi"},
		}, sink)
	}()

	deadline := time.Now().Add(2 * time.Second)
	for fake.promptCalls.Load() == 0 && time.Now().Before(deadline) {
		time.Sleep(5 * time.Millisecond)
	}

	fake.push(map[string]any{
		"type": "session.error",
		"properties": map[string]any{
			"sessionID": "ses_1",
			"error": map[string]any{
				"name": "ModelError",
				"data": map[string]any{"message": "Model not found: foo/bar"},
			},
		},
	})

	select {
	case err := <-done:
		if err == nil {
			t.Fatal("expected error, got nil")
		}
		if !strings.Contains(err.Error(), "Model not found: foo/bar") {
			t.Fatalf("unexpected error: %v", err)
		}
	case <-time.After(3 * time.Second):
		t.Fatal("execute did not return")
	}

	var gotErr string
	for _, e := range sink.Events() {
		if e.Type == noderuntime.EventTypeError {
			gotErr = e.Error
		}
	}
	if gotErr != "Model not found: foo/bar" {
		t.Fatalf("expected runtime error event, got %q", gotErr)
	}
}

func TestCLIExecuteOpencodeSSE_ContextCancelAbortsSession(t *testing.T) {
	fake, srv := newOpencodeFakeServer(t, "ses_1")

	cfg := config.CLIConf{
		Enabled: true,
		Profiles: map[string]config.CLIProfileConf{
			"opencode": opencodeSSEProfile(srv.URL),
		},
	}
	c := clipkg.New(cfg, zap.NewNop())
	sink := &testutil.FakeSink{}

	ctx, cancel := context.WithCancel(context.Background())
	done := make(chan error, 1)
	go func() {
		done <- c.Execute(ctx, noderuntime.ExecutionSpec{
			RunID:  "run-cancel",
			Target: "opencode",
			Input:  map[string]any{"prompt": "hi"},
		}, sink)
	}()

	deadline := time.Now().Add(2 * time.Second)
	for fake.promptCalls.Load() == 0 && time.Now().Before(deadline) {
		time.Sleep(5 * time.Millisecond)
	}
	cancel()

	select {
	case err := <-done:
		if err != noderuntime.ErrRunCancelled {
			t.Fatalf("expected ErrRunCancelled, got %v", err)
		}
	case <-time.After(3 * time.Second):
		t.Fatal("execute did not return after cancel")
	}

	var cancelEvent bool
	var msg string
	for _, e := range sink.Events() {
		if e.Type == noderuntime.EventTypeCancelled {
			cancelEvent = true
			msg = e.Message
		}
	}
	if !cancelEvent {
		t.Fatal("expected cancelled event")
	}
	if msg != "user-cancel" {
		t.Fatalf("expected user-cancel, got %q", msg)
	}

	// Allow a short window for the abort POST to arrive.
	deadline = time.Now().Add(1 * time.Second)
	for fake.abortCalls.Load() == 0 && time.Now().Before(deadline) {
		time.Sleep(10 * time.Millisecond)
	}
	if fake.abortCalls.Load() == 0 {
		t.Fatal("expected /session/{id}/abort to be called")
	}
}