package wing_test

import (
	"context"
	"errors"
	"strings"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"github.com/mathiasbq/hyperguild/ingestion/internal/wing"
)

func completes(reply string, err error) wing.CompleteFunc {
	return func(_ context.Context, _, _ string) (string, error) { return reply, err }
}

func TestLLMClassifier_ParsesTheReply(t *testing.T) {
	tests := []struct {
		name    string
		reply   string
		want    wing.Suggestion
		wantErr bool
	}{
		{"bare json", `{"wing":"tapir","confidence":0.9,"reason":"video summariser"}`, wing.Suggestion{Wing: "tapir", Confidence: 0.9, Reason: "video summariser"}, false},
		{"json inside prose and fences", "Sure!\n```json\n{\"wing\":\"homelab\",\"confidence\":0.7,\"reason\":\"k3s\"}\n```\nDone.", wing.Suggestion{Wing: "homelab", Confidence: 0.7, Reason: "k3s"}, false},
		{"none means abstain", `{"wing":"none","confidence":0.2,"reason":"generic"}`, wing.Suggestion{Wing: "", Confidence: 0.2, Reason: "generic"}, false},
		{"confidence above 1 is clamped", `{"wing":"tapir","confidence":7,"reason":"x"}`, wing.Suggestion{Wing: "tapir", Confidence: 1, Reason: "x"}, false},
		{"negative confidence is clamped", `{"wing":"tapir","confidence":-1,"reason":"x"}`, wing.Suggestion{Wing: "tapir", Confidence: 0, Reason: "x"}, false},
		{"empty reply (a reasoning model that ran out of tokens)", ``, wing.Suggestion{}, true},
		{"no json at all", `I think it is tapir`, wing.Suggestion{}, true},
		{"malformed json", `{"wing":"tapir","confidence":`, wing.Suggestion{}, true},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			c := wing.NewLLMClassifier(completes(tt.reply, nil))
			got, err := c.Classify(context.Background(), "note", []string{"tapir", "homelab"})
			if tt.wantErr {
				require.Error(t, err)
				return
			}
			require.NoError(t, err)
			assert.Equal(t, tt.want, got)
		})
	}
}

func TestLLMClassifier_PropagatesTheModelError(t *testing.T) {
	boom := errors.New("model down")
	_, err := wing.NewLLMClassifier(completes("", boom)).Classify(context.Background(), "n", []string{"tapir"})
	assert.ErrorIs(t, err, boom)
}

func TestLLMClassifier_PromptListsCandidatesAndBoundsTheNote(t *testing.T) {
	var gotUser string
	c := wing.NewLLMClassifier(func(_ context.Context, _, user string) (string, error) {
		gotUser = user
		return `{"wing":"tapir","confidence":0.9,"reason":"x"}`, nil
	})
	long := strings.Repeat("word ", 5000)
	_, err := c.Classify(context.Background(), long, []string{"tapir", "homelab"})
	require.NoError(t, err)
	assert.Contains(t, gotUser, "tapir")
	assert.Contains(t, gotUser, "homelab")
	assert.Less(t, len(gotUser), 12000, "a whole transcript must not be sent as the classification input")
}