package openai

import (
	"encoding/json"
	"testing"

	"nex/backend/internal/conversion"
	"nex/backend/internal/conversion/canonical"

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

func TestDecodeEmbeddingRequest(t *testing.T) {
	body := []byte(`{"model":"text-embedding-3-small","input":"hello world","encoding_format":"float","dimensions":256}`)
	req, err := decodeEmbeddingRequest(body)
	require.NoError(t, err)
	assert.Equal(t, "text-embedding-3-small", req.Model)
	assert.Equal(t, "hello world", req.Input)
	assert.Equal(t, "float", req.EncodingFormat)
	require.NotNil(t, req.Dimensions)
	assert.Equal(t, 256, *req.Dimensions)
}

func TestDecodeEmbeddingRequest_ArrayInput(t *testing.T) {
	body := []byte(`{"model":"text-embedding","input":["hello","world"]}`)
	req, err := decodeEmbeddingRequest(body)
	require.NoError(t, err)
	assert.Equal(t, "text-embedding", req.Model)
	inputArr, ok := req.Input.([]any)
	require.True(t, ok)
	assert.Len(t, inputArr, 2)
}

func TestDecodeEmbeddingRequest_InvalidJSON(t *testing.T) {
	_, err := decodeEmbeddingRequest([]byte(`invalid`))
	assert.Error(t, err)
}

func TestDecodeEmbeddingResponse(t *testing.T) {
	body := []byte(`{
		"object": "list",
		"data": [{"index": 0, "embedding": [0.1, 0.2, 0.3]}],
		"model": "text-embedding-3-small",
		"usage": {"prompt_tokens": 5, "total_tokens": 5}
	}`)
	resp, err := decodeEmbeddingResponse(body)
	require.NoError(t, err)
	assert.Equal(t, "text-embedding-3-small", resp.Model)
	assert.Len(t, resp.Data, 1)
	assert.Equal(t, 0, resp.Data[0].Index)
	assert.Equal(t, 5, resp.Usage.PromptTokens)
}

func TestDecodeRerankRequest(t *testing.T) {
	topN := 3
	returnDocs := true
	body := []byte(`{"model":"rerank-1","query":"what is AI","documents":["doc1","doc2"],"top_n":3,"return_documents":true}`)
	req, err := decodeRerankRequest(body)
	require.NoError(t, err)
	assert.Equal(t, "rerank-1", req.Model)
	assert.Equal(t, "what is AI", req.Query)
	assert.Equal(t, []string{"doc1", "doc2"}, req.Documents)
	require.NotNil(t, req.TopN)
	assert.Equal(t, topN, *req.TopN)
	require.NotNil(t, req.ReturnDocuments)
	assert.Equal(t, returnDocs, *req.ReturnDocuments)
}

func TestDecodeRerankResponse(t *testing.T) {
	doc := "relevant doc"
	body := []byte(`{
		"results": [{"index": 0, "relevance_score": 0.95, "document": "relevant doc"}],
		"model": "rerank-1"
	}`)
	resp, err := decodeRerankResponse(body)
	require.NoError(t, err)
	assert.Equal(t, "rerank-1", resp.Model)
	assert.Len(t, resp.Results, 1)
	assert.Equal(t, 0, resp.Results[0].Index)
	assert.InDelta(t, 0.95, resp.Results[0].RelevanceScore, 0.001)
	require.NotNil(t, resp.Results[0].Document)
	assert.Equal(t, doc, *resp.Results[0].Document)
}

func TestDecodeModelInfoResponse(t *testing.T) {
	body := []byte(`{"id":"gpt-4","object":"model","created":1700000000,"owned_by":"openai"}`)
	info, err := decodeModelInfoResponse(body)
	require.NoError(t, err)
	assert.Equal(t, "gpt-4", info.ID)
	assert.Equal(t, int64(1700000000), info.Created)
	assert.Equal(t, "openai", info.OwnedBy)
}

func TestEncodeEmbeddingRequest(t *testing.T) {
	req := &canonical.CanonicalEmbeddingRequest{
		Model:          "text-embedding-3-small",
		Input:          "hello",
		EncodingFormat: "float",
	}
	provider := conversion.NewTargetProvider("", "key", "my-embedding-model")

	body, err := encodeEmbeddingRequest(req, provider)
	require.NoError(t, err)

	var result map[string]any
	require.NoError(t, json.Unmarshal(body, &result))
	assert.Equal(t, "my-embedding-model", result["model"])
	assert.Equal(t, "hello", result["input"])
	assert.Equal(t, "float", result["encoding_format"])
}

func TestEncodeEmbeddingRequest_WithDimensions(t *testing.T) {
	dims := 256
	req := &canonical.CanonicalEmbeddingRequest{
		Model:      "text-embedding",
		Input:      "test",
		Dimensions: &dims,
	}
	provider := conversion.NewTargetProvider("", "key", "model")

	body, err := encodeEmbeddingRequest(req, provider)
	require.NoError(t, err)

	var result map[string]any
	require.NoError(t, json.Unmarshal(body, &result))
	assert.Equal(t, float64(256), result["dimensions"])
}

func TestEncodeEmbeddingResponse(t *testing.T) {
	resp := &canonical.CanonicalEmbeddingResponse{
		Data:  []canonical.EmbeddingData{{Index: 0, Embedding: []float64{0.1, 0.2}}},
		Model: "text-embedding",
		Usage: canonical.EmbeddingUsage{PromptTokens: 3, TotalTokens: 3},
	}

	body, err := encodeEmbeddingResponse(resp)
	require.NoError(t, err)

	var result map[string]any
	require.NoError(t, json.Unmarshal(body, &result))
	assert.Equal(t, "list", result["object"])
	assert.Equal(t, "text-embedding", result["model"])
}

func TestEncodeRerankRequest(t *testing.T) {
	topN := 5
	req := &canonical.CanonicalRerankRequest{
		Model:     "rerank-1",
		Query:     "what is AI",
		Documents: []string{"doc1", "doc2"},
		TopN:      &topN,
	}
	provider := conversion.NewTargetProvider("", "key", "my-rerank-model")

	body, err := encodeRerankRequest(req, provider)
	require.NoError(t, err)

	var result map[string]any
	require.NoError(t, json.Unmarshal(body, &result))
	assert.Equal(t, "my-rerank-model", result["model"])
	assert.Equal(t, "what is AI", result["query"])
}

func TestEncodeRerankResponse(t *testing.T) {
	doc := "relevant passage"
	resp := &canonical.CanonicalRerankResponse{
		Results: []canonical.RerankResult{
			{Index: 0, RelevanceScore: 0.95, Document: &doc},
		},
		Model: "rerank-1",
	}

	body, err := encodeRerankResponse(resp)
	require.NoError(t, err)

	var result map[string]any
	require.NoError(t, json.Unmarshal(body, &result))
	assert.Equal(t, "rerank-1", result["model"])
	results := result["results"].([]any)
	assert.Len(t, results, 1)
}

func TestEncodeModelInfoResponse(t *testing.T) {
	info := &canonical.CanonicalModelInfo{
		ID:      "gpt-4",
		Name:    "GPT-4",
		Created: 1700000000,
		OwnedBy: "openai",
	}

	body, err := encodeModelInfoResponse(info)
	require.NoError(t, err)

	var result map[string]any
	require.NoError(t, json.Unmarshal(body, &result))
	assert.Equal(t, "gpt-4", result["id"])
	assert.Equal(t, "model", result["object"])
}

func TestDecodeEmbeddingResponse_InvalidJSON(t *testing.T) {
	_, err := decodeEmbeddingResponse([]byte(`invalid`))
	assert.Error(t, err)
}

func TestDecodeRerankRequest_InvalidJSON(t *testing.T) {
	_, err := decodeRerankRequest([]byte(`invalid`))
	assert.Error(t, err)
}

func TestDecodeRerankResponse_InvalidJSON(t *testing.T) {
	_, err := decodeRerankResponse([]byte(`invalid`))
	assert.Error(t, err)
}

func TestDecodeModelInfoResponse_InvalidJSON(t *testing.T) {
	_, err := decodeModelInfoResponse([]byte(`invalid`))
	assert.Error(t, err)
}

func TestDecodeRequest_ThinkingNone(t *testing.T) {
	body := []byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"reasoning_effort":"none"}`)
	req, err := decodeRequest(body)
	require.NoError(t, err)
	require.NotNil(t, req.Thinking)
	assert.Equal(t, "disabled", req.Thinking.Type)
}

func TestDecodeRequest_ThinkingMinimal(t *testing.T) {
	body := []byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"reasoning_effort":"minimal"}`)
	req, err := decodeRequest(body)
	require.NoError(t, err)
	require.NotNil(t, req.Thinking)
	assert.Equal(t, "enabled", req.Thinking.Type)
	assert.Equal(t, "low", req.Thinking.Effort)
}

func TestDecodeRequest_OutputFormat_Text(t *testing.T) {
	body := []byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"response_format":{"type":"text"}}`)
	req, err := decodeRequest(body)
	require.NoError(t, err)
	assert.Nil(t, req.OutputFormat)
}

func TestDecodeRequest_DeprecatedFunctionCall(t *testing.T) {
	body := []byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"function_call":"auto","functions":[{"name":"fn1","parameters":{}}]}`)
	req, err := decodeRequest(body)
	require.NoError(t, err)
	assert.Equal(t, "auto", req.ToolChoice.Type)
	assert.Len(t, req.Tools, 1)
}

func TestDecodeRequest_FunctionMessage(t *testing.T) {
	body := []byte(`{
		"model": "gpt-4",
		"messages": [
			{"role": "user", "content": "hi"},
			{"role": "function", "name": "get_weather", "content": "sunny"}
		]
	}`)
	req, err := decodeRequest(body)
	require.NoError(t, err)
	assert.Len(t, req.Messages, 2)
	assert.Equal(t, canonical.RoleTool, req.Messages[1].Role)
}

func TestDecodeRequest_StopString(t *testing.T) {
	body := []byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"stop":"END"}`)
	req, err := decodeRequest(body)
	require.NoError(t, err)
	assert.Equal(t, []string{"END"}, req.Parameters.StopSequences)
}

func TestDecodeRequest_StopEmptyString(t *testing.T) {
	body := []byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"stop":""}`)
	req, err := decodeRequest(body)
	require.NoError(t, err)
	assert.Nil(t, req.Parameters.StopSequences)
}

func TestDecodeResponse_EmptyChoices(t *testing.T) {
	body := []byte(`{"id":"resp-1","model":"gpt-4","choices":[],"usage":{"prompt_tokens":0,"completion_tokens":0,"total_tokens":0}}`)
	resp, err := decodeResponse(body)
	require.NoError(t, err)
	assert.Equal(t, "resp-1", resp.ID)
	assert.Len(t, resp.Content, 1)
	assert.Equal(t, "", resp.Content[0].Text)
}

func TestDecodeResponse_FunctionCallFinishReason(t *testing.T) {
	body := []byte(`{
		"id":"r1","model":"gpt-4",
		"choices":[{"index":0,"message":{"role":"assistant","content":"ok"},"finish_reason":"function_call"}],
		"usage":{"prompt_tokens":1,"completion_tokens":1,"total_tokens":2}
	}`)
	resp, err := decodeResponse(body)
	require.NoError(t, err)
	assert.Equal(t, canonical.StopReasonToolUse, *resp.StopReason)
}

func TestEncodeRequest_DisabledThinking(t *testing.T) {
	req := &canonical.CanonicalRequest{
		Model:    "gpt-4",
		Messages: []canonical.CanonicalMessage{{Role: canonical.RoleUser, Content: []canonical.ContentBlock{canonical.NewTextBlock("hi")}}},
		Thinking: &canonical.ThinkingConfig{Type: "disabled"},
	}
	provider := conversion.NewTargetProvider("", "key", "model")

	body, err := encodeRequest(req, provider)
	require.NoError(t, err)

	var result map[string]any
	require.NoError(t, json.Unmarshal(body, &result))
	assert.Equal(t, "none", result["reasoning_effort"])
}

func TestEncodeRequest_OutputFormat_JSONObject(t *testing.T) {
	req := &canonical.CanonicalRequest{
		Model:        "gpt-4",
		Messages:     []canonical.CanonicalMessage{{Role: canonical.RoleUser, Content: []canonical.ContentBlock{canonical.NewTextBlock("hi")}}},
		OutputFormat: &canonical.OutputFormat{Type: "json_object"},
	}
	provider := conversion.NewTargetProvider("", "key", "model")

	body, err := encodeRequest(req, provider)
	require.NoError(t, err)

	var result map[string]any
	require.NoError(t, json.Unmarshal(body, &result))
	rf, ok := result["response_format"].(map[string]any)
	require.True(t, ok)
	assert.Equal(t, "json_object", rf["type"])
}

func TestEncodeRequest_PublicFields(t *testing.T) {
	parallel := true
	req := &canonical.CanonicalRequest{
		Model:           "gpt-4",
		Messages:        []canonical.CanonicalMessage{{Role: canonical.RoleUser, Content: []canonical.ContentBlock{canonical.NewTextBlock("hi")}}},
		UserID:          "user-123",
		ParallelToolUse: &parallel,
	}
	provider := conversion.NewTargetProvider("", "key", "model")

	body, err := encodeRequest(req, provider)
	require.NoError(t, err)

	var result map[string]any
	require.NoError(t, json.Unmarshal(body, &result))
	assert.Equal(t, "user-123", result["user"])
	assert.Equal(t, true, result["parallel_tool_calls"])
}

func TestEncodeResponse_UsageWithCacheAndReasoning(t *testing.T) {
	cache := 80
	reasoning := 20
	sr := canonical.StopReasonEndTurn
	resp := &canonical.CanonicalResponse{
		ID:      "r1",
		Model:   "gpt-4",
		Content: []canonical.ContentBlock{canonical.NewTextBlock("ok")},
		StopReason: &sr,
		Usage: canonical.CanonicalUsage{
			InputTokens:     100,
			OutputTokens:    50,
			CacheReadTokens: &cache,
			ReasoningTokens: &reasoning,
		},
	}

	body, err := encodeResponse(resp)
	require.NoError(t, err)

	var result map[string]any
	require.NoError(t, json.Unmarshal(body, &result))
	usage := result["usage"].(map[string]any)
	assert.Equal(t, float64(100), usage["prompt_tokens"])
	ptd, ok := usage["prompt_tokens_details"].(map[string]any)
	require.True(t, ok)
	assert.Equal(t, float64(80), ptd["cached_tokens"])
	ctd, ok := usage["completion_tokens_details"].(map[string]any)
	require.True(t, ok)
	assert.Equal(t, float64(20), ctd["reasoning_tokens"])
}

func TestEncodeResponse_StopReasons(t *testing.T) {
	tests := []struct {
		name       string
		stopReason canonical.StopReason
		want       string
	}{
		{"end_turn→stop", canonical.StopReasonEndTurn, "stop"},
		{"max_tokens→length", canonical.StopReasonMaxTokens, "length"},
		{"tool_use→tool_calls", canonical.StopReasonToolUse, "tool_calls"},
		{"content_filter→content_filter", canonical.StopReasonContentFilter, "content_filter"},
		{"stop_sequence→stop", canonical.StopReasonStopSequence, "stop"},
		{"refusal→stop", canonical.StopReasonRefusal, "stop"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			sr := tt.stopReason
			resp := &canonical.CanonicalResponse{
				ID:         "r1",
				Model:      "gpt-4",
				Content:    []canonical.ContentBlock{canonical.NewTextBlock("ok")},
				StopReason: &sr,
				Usage:      canonical.CanonicalUsage{},
			}
			body, err := encodeResponse(resp)
			require.NoError(t, err)

			var result map[string]any
			require.NoError(t, json.Unmarshal(body, &result))
			choices := result["choices"].([]any)
			choice := choices[0].(map[string]any)
			assert.Equal(t, tt.want, choice["finish_reason"])
		})
	}
}

func TestMapErrorCode_AllCodes(t *testing.T) {
	assert.Equal(t, "invalid_request_error", mapErrorCode(conversion.ErrorCodeInvalidInput))
	assert.Equal(t, "invalid_request_error", mapErrorCode(conversion.ErrorCodeMissingRequiredField))
	assert.Equal(t, "invalid_request_error", mapErrorCode(conversion.ErrorCodeIncompatibleFeature))
	assert.Equal(t, "invalid_request_error", mapErrorCode(conversion.ErrorCodeFieldMappingFailure))
	assert.Equal(t, "invalid_request_error", mapErrorCode(conversion.ErrorCodeToolCallParseError))
	assert.Equal(t, "invalid_request_error", mapErrorCode(conversion.ErrorCodeJSONParseError))
	assert.Equal(t, "invalid_request_error", mapErrorCode(conversion.ErrorCodeProtocolConstraint))
	assert.Equal(t, "server_error", mapErrorCode(conversion.ErrorCodeStreamStateError))
	assert.Equal(t, "server_error", mapErrorCode(conversion.ErrorCodeUTF8DecodeError))
	assert.Equal(t, "server_error", mapErrorCode(conversion.ErrorCodeEncodingFailure))
	assert.Equal(t, "server_error", mapErrorCode(conversion.ErrorCodeInterfaceNotSupported))
}