package extract_test

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"github.com/netcell-it/deklarix/internal/extract"
	"github.com/netcell-it/deklarix/internal/rules"
)

// toolUseResponse baut eine minimale Anthropic-Messages-API-Antwort mit
// genau einem tool_use-Block, wie sie extract.Client erwartet.
func toolUseResponse(t *testing.T, toolName string, args any) []byte {
	t.Helper()
	input, err := json.Marshal(args)
	if err != nil {
		t.Fatalf("marshal args: %v", err)
	}
	body := map[string]any{
		"content": []map[string]any{
			{"type": "tool_use", "name": toolName, "input": json.RawMessage(input)},
		},
	}
	data, err := json.Marshal(body)
	if err != nil {
		t.Fatalf("marshal response: %v", err)
	}
	return data
}

func newTestClient(t *testing.T, handler http.HandlerFunc) *extract.Client {
	t.Helper()
	server := httptest.NewServer(handler)
	t.Cleanup(server.Close)
	c, err := extract.NewClient("test-key", extract.WithBaseURL(server.URL))
	if err != nil {
		t.Fatalf("NewClient: %v", err)
	}
	return c
}

func TestNewClientRejectsEmptyAPIKey(t *testing.T) {
	if _, err := extract.NewClient(""); err == nil {
		t.Fatal("expected error for empty apiKey, got nil")
	}
}

func TestExtractRejectsEmptyInput(t *testing.T) {
	called := false
	c := newTestClient(t, func(w http.ResponseWriter, r *http.Request) {
		called = true
	})
	_, err := c.Extract(context.Background(), extract.Input{Platform: "instagram"})
	if err == nil {
		t.Fatal("expected error for empty caption+image, got nil")
	}
	if called {
		t.Fatal("expected no HTTP call for invalid input, but the server was called")
	}
}

func TestExtractSuccess(t *testing.T) {
	var gotBody map[string]any
	c := newTestClient(t, func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/v1/messages" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		if got := r.Header.Get("x-api-key"); got != "test-key" {
			t.Errorf("x-api-key = %q, want test-key", got)
		}
		if err := json.NewDecoder(r.Body).Decode(&gotBody); err != nil {
			t.Fatalf("decode request body: %v", err)
		}
		w.WriteHeader(http.StatusOK)
		w.Write(toolUseResponse(t, "extrahiere_fakten", map[string]any{
			"gegenleistung":              "bezahlt",
			"kennzeichnung_vorhanden":    true,
			"kennzeichnung_wortlaut":     "Werbung",
			"kennzeichnung_vor_kuerzung": false,
		}))
	})

	got, err := c.Extract(context.Background(), extract.Input{
		Platform:       "instagram",
		Jurisdiction:   "DE",
		Caption:        "Schaut euch dieses Produkt an! Werbung wegen ...",
		ImageMediaType: "image/jpeg",
		ImageData:      []byte("fake-jpeg-bytes"),
	})
	if err != nil {
		t.Fatalf("Extract: %v", err)
	}

	want := rules.Facts{
		Platform:            "instagram",
		Jurisdiction:        "DE",
		Consideration:       rules.ConsiderationPaid,
		DisclosurePresent:   true,
		DisclosureWording:   "Werbung",
		DisclosureBeforeCut: false,
	}
	if got != want {
		t.Fatalf("Extract() = %+v, want %+v", got, want)
	}

	toolChoice, _ := gotBody["tool_choice"].(map[string]any)
	if toolChoice["name"] != "extrahiere_fakten" {
		t.Errorf("tool_choice.name = %v, want extrahiere_fakten", toolChoice["name"])
	}
	if gotBody["system"] == nil || gotBody["system"] == "" {
		t.Error("expected a non-empty system prompt in the request")
	}
}

func TestExtractPassesThroughUnclear(t *testing.T) {
	c := newTestClient(t, func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write(toolUseResponse(t, "extrahiere_fakten", map[string]any{
			"gegenleistung":              "unklar",
			"kennzeichnung_vorhanden":    false,
			"kennzeichnung_wortlaut":     "",
			"kennzeichnung_vor_kuerzung": false,
		}))
	})

	got, err := c.Extract(context.Background(), extract.Input{Platform: "tiktok", Caption: "..."})
	if err != nil {
		t.Fatalf("Extract: %v", err)
	}
	if got.Consideration != rules.ConsiderationUnclear {
		t.Fatalf("Consideration = %q, want unklar", got.Consideration)
	}
}

func TestExtractRejectsInvalidConsiderationValue(t *testing.T) {
	c := newTestClient(t, func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write(toolUseResponse(t, "extrahiere_fakten", map[string]any{
			"gegenleistung":              "vielleicht", // nicht im Enum
			"kennzeichnung_vorhanden":    false,
			"kennzeichnung_wortlaut":     "",
			"kennzeichnung_vor_kuerzung": false,
		}))
	})

	if _, err := c.Extract(context.Background(), extract.Input{Platform: "instagram", Caption: "x"}); err == nil {
		t.Fatal("expected error for out-of-enum gegenleistung value, got nil")
	}
}

func TestExtractRejectsMissingToolUseBlock(t *testing.T) {
	c := newTestClient(t, func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte(`{"content":[{"type":"text","text":"kein tool_use hier"}]}`))
	})

	if _, err := c.Extract(context.Background(), extract.Input{Platform: "instagram", Caption: "x"}); err == nil {
		t.Fatal("expected error when response has no tool_use block, got nil")
	}
}

func TestExtractRejectsMalformedToolInput(t *testing.T) {
	c := newTestClient(t, func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte(`{"content":[{"type":"tool_use","name":"extrahiere_fakten","input":"not-an-object"}]}`))
	})

	if _, err := c.Extract(context.Background(), extract.Input{Platform: "instagram", Caption: "x"}); err == nil {
		t.Fatal("expected error for malformed tool input, got nil")
	}
}

func TestExtractPropagatesAPIError(t *testing.T) {
	c := newTestClient(t, func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusTooManyRequests)
		w.Write([]byte(`{"error":{"type":"rate_limit_error","message":"too many requests"}}`))
	})

	_, err := c.Extract(context.Background(), extract.Input{Platform: "instagram", Caption: "x"})
	if err == nil {
		t.Fatal("expected error for non-200 status, got nil")
	}
	if got := err.Error(); !strings.Contains(got, "too many requests") {
		t.Fatalf("error %q does not mention API message", got)
	}
}