package llamaswap

import (
	"context"
	"encoding/base64"
	"errors"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"gitea.stevedudenhoeffer.com/steve/majordomo/llm"
	"gitea.stevedudenhoeffer.com/steve/majordomo/videogen"
)

func TestVideoGenerate(t *testing.T) {
	var gotPath, gotContentType string
	var gotForm map[string]string
	var gotFrame []byte
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		gotPath = r.URL.Path
		gotContentType = r.Header.Get("Content-Type")
		if err := r.ParseMultipartForm(32 << 20); err != nil {
			t.Errorf("parse form: %v", err)
			return
		}
		gotForm = map[string]string{}
		for k, v := range r.MultipartForm.Value {
			gotForm[k] = v[0]
		}
		if f, _, err := r.FormFile("input_reference"); err == nil {
			gotFrame, _ = io.ReadAll(f)
			f.Close()
		}
		w.Header().Set("Content-Type", "video/mp4")
		_, _ = w.Write([]byte("fake-mp4-bytes"))
	}))
	defer srv.Close()

	p := New(WithBaseURL(srv.URL), WithHTTPClient(srv.Client()))
	vm, err := p.VideoModel("videogen-wan")
	if err != nil {
		t.Fatalf("VideoModel: %v", err)
	}

	frame, _ := base64.StdEncoding.DecodeString(onePixelPNG)
	res, err := vm.Generate(context.Background(),
		videogen.Request{Prompt: "a cat surfing", InitImage: &videogen.Image{MIME: "image/png", Data: frame}},
		videogen.WithSize("1280x704"),
		videogen.WithNumFrames(81),
		videogen.WithFPS(16),
		videogen.WithSteps(4),
		videogen.WithGuidanceScale(1.0),
		videogen.WithNegativePrompt("blurry"),
		videogen.WithSeed(42),
	)
	if err != nil {
		t.Fatalf("Generate: %v", err)
	}
	if string(res.Video.Data) != "fake-mp4-bytes" || res.Video.MIME != "video/mp4" {
		t.Fatalf("video = %d bytes, MIME %q", len(res.Video.Data), res.Video.MIME)
	}

	if gotPath != "/v1/videos/sync" {
		t.Errorf("path = %q", gotPath)
	}
	if !strings.HasPrefix(gotContentType, "multipart/form-data") {
		t.Errorf("content-type = %q", gotContentType)
	}
	want := map[string]string{
		"model":               "videogen-wan",
		"prompt":              "a cat surfing",
		"negative_prompt":     "blurry",
		"width":               "1280",
		"height":              "704",
		"num_frames":          "81",
		"fps":                 "16",
		"num_inference_steps": "4",
		"guidance_scale":      "1",
		"seed":                "42",
	}
	for k, v := range want {
		if gotForm[k] != v {
			t.Errorf("form[%q] = %q, want %q", k, gotForm[k], v)
		}
	}
	if string(gotFrame) != string(frame) {
		t.Errorf("input_reference = %d bytes, want %d", len(gotFrame), len(frame))
	}
}

func TestVideoGenerateOmitsUnsetOverrides(t *testing.T) {
	var gotForm map[string][]string
	var hadFrame bool
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_ = r.ParseMultipartForm(32 << 20)
		gotForm = r.MultipartForm.Value
		_, _, err := r.FormFile("input_reference")
		hadFrame = err == nil
		w.Header().Set("Content-Type", "video/mp4")
		_, _ = w.Write([]byte("v"))
	}))
	defer srv.Close()

	p := New(WithBaseURL(srv.URL), WithHTTPClient(srv.Client()))
	vm, _ := p.VideoModel("videogen-wan")
	if _, err := vm.Generate(context.Background(), videogen.Request{Prompt: "x"}); err != nil {
		t.Fatalf("Generate: %v", err)
	}
	for _, k := range []string{"negative_prompt", "width", "height", "num_frames", "fps", "num_inference_steps", "guidance_scale", "seed"} {
		if _, ok := gotForm[k]; ok {
			t.Errorf("form field %q sent, want omitted", k)
		}
	}
	if hadFrame {
		t.Error("input_reference sent, want omitted")
	}
}

func TestVideoGenerateValidation(t *testing.T) {
	p := New(WithBaseURL("http://unused.invalid"))
	vm, _ := p.VideoModel("videogen-wan")

	cases := []struct {
		name string
		req  videogen.Request
	}{
		{"empty prompt", videogen.Request{}},
		{"negative frames", videogen.Request{Prompt: "x", NumFrames: -1}},
		{"negative fps", videogen.Request{Prompt: "x", FPS: -1}},
		{"empty init image", videogen.Request{Prompt: "x", InitImage: &videogen.Image{}}},
		{"bad size", videogen.Request{Prompt: "x", Size: "banana"}},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			_, err := vm.Generate(context.Background(), tc.req)
			if !errors.Is(err, llm.ErrUnsupported) {
				t.Fatalf("err = %v, want ErrUnsupported", err)
			}
		})
	}
}

func TestVideoGenerateUpstreamError(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, `{"error":{"message":"boom"}}`, http.StatusInternalServerError)
	}))
	defer srv.Close()

	p := New(WithBaseURL(srv.URL), WithHTTPClient(srv.Client()))
	vm, _ := p.VideoModel("videogen-wan")
	_, err := vm.Generate(context.Background(), videogen.Request{Prompt: "x"})
	var apiErr *llm.APIError
	if !errors.As(err, &apiErr) {
		t.Fatalf("err = %v, want *llm.APIError", err)
	}
}

func TestVideoGenerateEmptyResponse(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "video/mp4")
	}))
	defer srv.Close()

	p := New(WithBaseURL(srv.URL), WithHTTPClient(srv.Client()))
	vm, _ := p.VideoModel("videogen-wan")
	_, err := vm.Generate(context.Background(), videogen.Request{Prompt: "x"})
	var apiErr *llm.APIError
	if !errors.As(err, &apiErr) {
		t.Fatalf("err = %v, want *llm.APIError for empty body", err)
	}
}

func TestVideoModelRequiresBaseURL(t *testing.T) {
	p := New()
	if _, err := p.VideoModel("videogen-wan"); err == nil {
		t.Fatal("VideoModel with no base URL should error")
	}
}

func TestVideoMIME(t *testing.T) {
	// A minimal ISO-BMFF prefix http.DetectContentType sniffs as video/mp4
	// (the "mp4" brand prefix must appear inside the declared ftyp box).
	mp4Magic := append([]byte{0, 0, 0, 20}, []byte("ftypmp42\x00\x00\x00\x00mp42")...)
	cases := []struct {
		contentType string
		data        []byte
		want        string
	}{
		{"video/webm", []byte("x"), "video/webm"},
		{"video/mp4; charset=binary", []byte("x"), "video/mp4"},
		{"application/octet-stream", mp4Magic, "video/mp4"},
		// Neither declared nor sniffable as video → "" (Generate errors).
		{"application/octet-stream", []byte(`{"id":"job-1"}`), ""},
		{"", []byte("x"), ""},
	}
	for _, tc := range cases {
		if got := videoMIME(tc.contentType, tc.data); got != tc.want {
			t.Errorf("videoMIME(%q, %q) = %q, want %q", tc.contentType, tc.data, got, tc.want)
		}
	}
}

func TestVideoGenerateNonVideoBodyErrors(t *testing.T) {
	// A stock async /v1/videos handler mounted at the sync path (or an HTML
	// error page behind a proxy) answers 200 with a non-video body — that
	// must be an error, never a "successful" garbage clip.
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"id":"job-1","status":"queued"}`))
	}))
	defer srv.Close()

	p := New(WithBaseURL(srv.URL), WithHTTPClient(srv.Client()))
	vm, _ := p.VideoModel("videogen-wan")
	_, err := vm.Generate(context.Background(), videogen.Request{Prompt: "x"})
	var apiErr *llm.APIError
	if !errors.As(err, &apiErr) {
		t.Fatalf("err = %v, want *llm.APIError for non-video 2xx body", err)
	}
	if !strings.Contains(apiErr.Message, "not a video") {
		t.Errorf("message = %q, want mention of non-video body", apiErr.Message)
	}
}