package secutools

import (
	"context"
	"encoding/json"
	"errors"
	"net/http"
	"net/http/httptest"
	"sync/atomic"
	"testing"
	"time"
)

// TestSubmitJob_HappyPath verifies the request body and headers match the
// secutools contract and the response is decoded.
func TestSubmitJob_HappyPath(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/jobs" {
			t.Errorf("unexpected path %q", r.URL.Path)
		}
		if r.Method != http.MethodPost {
			t.Errorf("unexpected method %q", r.Method)
		}
		if r.Header.Get("X-API-Key") != "key123" {
			t.Errorf("missing/incorrect X-API-Key: %q", r.Header.Get("X-API-Key"))
		}
		var got JobRequest
		if err := json.NewDecoder(r.Body).Decode(&got); err != nil {
			t.Fatalf("decode: %v", err)
		}
		if got.Type != TypeAnalyze || got.PreferredAI != "gpu" {
			t.Errorf("payload mismatch: %+v", got)
		}
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"job_id":"abc","status":"pending"}`))
	}))
	defer srv.Close()

	c := NewHTTPClient(srv.URL, "key123", srv.Client())
	resp, err := c.SubmitJob(context.Background(), &JobRequest{
		Type:        TypeAnalyze,
		Priority:    PriorityHigh,
		Prompt:      "hi",
		PreferredAI: "gpu",
	})
	if err != nil {
		t.Fatalf("SubmitJob: %v", err)
	}
	if resp.JobID != "abc" || resp.Status != "pending" {
		t.Errorf("unexpected response: %+v", resp)
	}
}

// TestSubmitJob_HTTPError surfaces non-2xx responses as errors.
func TestSubmitJob_HTTPError(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
		_, _ = w.Write([]byte("boom"))
	}))
	defer srv.Close()

	c := NewHTTPClient(srv.URL, "k", srv.Client())
	if _, err := c.SubmitJob(context.Background(), &JobRequest{Type: TypeAnalyze, Prompt: "p"}); err == nil {
		t.Fatal("expected error on HTTP 500, got nil")
	}
}

// TestWaitForResult_PollsUntilCompleted verifies the polling loop transitions
// pending → running → completed and fetches the result.
func TestWaitForResult_PollsUntilCompleted(t *testing.T) {
	var calls atomic.Int64
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		switch r.URL.Path {
		case "/api/v1/jobs/job1":
			n := calls.Add(1)
			status := "pending"
			if n >= 2 {
				status = "completed"
			}
			_, _ = w.Write([]byte(`{"job_id":"job1","status":"` + status + `","provider":"gpu"}`))
		case "/api/v1/jobs/job1/result":
			_, _ = w.Write([]byte(`{"job_id":"job1","response":"done","provider":"gpu","cost_cad":0.005}`))
		default:
			t.Errorf("unexpected path %q", r.URL.Path)
		}
	}))
	defer srv.Close()

	c := NewHTTPClient(srv.URL, "k", srv.Client())
	// Override poll cadence indirectly: short timeout proves we don't spin
	// 2s per poll; the test runs in well under 10s real time.
	res, err := c.WaitForResult(context.Background(), "job1", 30*time.Second)
	if err != nil {
		t.Fatalf("WaitForResult: %v", err)
	}
	if res.Response != "done" || res.Provider != "gpu" {
		t.Errorf("unexpected result: %+v", res)
	}
}

// TestWaitForResult_FailedJob returns ErrJobFailed when secutools reports
// terminal failure.
func TestWaitForResult_FailedJob(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"job_id":"jobX","status":"failed","error":"oom"}`))
	}))
	defer srv.Close()

	c := NewHTTPClient(srv.URL, "k", srv.Client())
	_, err := c.WaitForResult(context.Background(), "jobX", 5*time.Second)
	if !errors.Is(err, ErrJobFailed) {
		t.Errorf("expected ErrJobFailed, got %v", err)
	}
}

// TestSubmitJob_RetriesOn5xx verifies the client retries transient 500s
// and succeeds on a later attempt. Uses a tight retry delay so the test
// runs in milliseconds.
func TestSubmitJob_RetriesOn5xx(t *testing.T) {
	var calls atomic.Int64
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		n := calls.Add(1)
		if n < 3 {
			w.WriteHeader(http.StatusInternalServerError)
			_, _ = w.Write([]byte("transient"))
			return
		}
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"job_id":"ok","status":"pending"}`))
	}))
	defer srv.Close()

	c := NewHTTPClient(srv.URL, "k", srv.Client())
	c.SetRetryPolicy(3, 1*time.Millisecond)

	resp, err := c.SubmitJob(context.Background(), &JobRequest{Type: TypeAnalyze, Prompt: "p"})
	if err != nil {
		t.Fatalf("expected success after retries, got %v (calls=%d)", err, calls.Load())
	}
	if resp.JobID != "ok" {
		t.Errorf("unexpected response: %+v", resp)
	}
	if calls.Load() != 3 {
		t.Errorf("expected 3 attempts, got %d", calls.Load())
	}
}

// TestSubmitJob_DoesNotRetry4xx ensures client errors short-circuit
// without burning retries (e.g. wrong API key).
func TestSubmitJob_DoesNotRetry4xx(t *testing.T) {
	var calls atomic.Int64
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		calls.Add(1)
		w.WriteHeader(http.StatusUnauthorized)
		_, _ = w.Write([]byte("bad key"))
	}))
	defer srv.Close()

	c := NewHTTPClient(srv.URL, "k", srv.Client())
	c.SetRetryPolicy(3, 1*time.Millisecond)

	_, err := c.SubmitJob(context.Background(), &JobRequest{Type: TypeAnalyze, Prompt: "p"})
	if err == nil {
		t.Fatal("expected error on 401")
	}
	if calls.Load() != 1 {
		t.Errorf("4xx must not retry, got %d calls", calls.Load())
	}
}

// TestWaitForResult_ContextCancel exits cleanly when the parent context is
// cancelled mid-poll.
func TestWaitForResult_ContextCancel(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"job_id":"j","status":"pending"}`))
	}))
	defer srv.Close()

	ctx, cancel := context.WithCancel(context.Background())
	cancel() // cancel immediately

	c := NewHTTPClient(srv.URL, "k", srv.Client())
	_, err := c.WaitForResult(ctx, "j", 10*time.Second)
	if err == nil {
		t.Fatal("expected error from cancelled context")
	}
}