package provider

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

	"haixun-backend/internal/model/ai/domain/enum"
	domai "haixun-backend/internal/model/ai/domain/usecase"
)

func TestOpenAICompatible_ListModels(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodGet || r.URL.Path != "/models" {
			t.Fatalf("unexpected request: %s %s", r.Method, r.URL.Path)
		}
		if got := r.Header.Get("Authorization"); got != "Bearer test-token" {
			t.Fatalf("unexpected auth header: %s", got)
		}
		_, _ = w.Write([]byte(`{"data":[{"id":"grok-3-fast"},{"id":"grok-3"},{"id":""}]}`))
	}))
	defer server.Close()

	p := NewOpenAICompatible(enum.ProviderXAI, server.URL)
	models, err := p.ListModels(context.Background(), domai.Credential{APIKey: "test-token"})
	if err != nil {
		t.Fatalf("ListModels() error = %v", err)
	}

	want := []string{"grok-3", "grok-3-fast"}
	if len(models) != len(want) {
		t.Fatalf("models = %v, want %v", models, want)
	}
	for i, id := range want {
		if models[i] != id {
			t.Fatalf("models[%d] = %s, want %s", i, models[i], id)
		}
	}
}

func TestOpenAICompatible_ListModels_MissingToken(t *testing.T) {
	p := NewOpenAICompatible(enum.ProviderXAI, "https://example.com")
	_, err := p.ListModels(context.Background(), domai.Credential{})
	if err == nil {
		t.Fatal("expected error for missing token")
	}
}

func TestOpenAICompatible_GenerateText_UsesContent(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost || r.URL.Path != "/chat/completions" {
			t.Fatalf("unexpected request: %s %s", r.Method, r.URL.Path)
		}
		body, _ := io.ReadAll(r.Body)
		var req chatCompletionRequest
		if err := json.Unmarshal(body, &req); err != nil {
			t.Fatalf("unmarshal request: %v", err)
		}
		if req.Stream {
			t.Fatal("expected non-stream request")
		}
		if req.Thinking == nil || req.Thinking.Type != "disabled" {
			t.Fatalf("thinking = %+v, want disabled for deepseek on opencode", req.Thinking)
		}
		if req.MaxTokens == nil || *req.MaxTokens < 2048 {
			t.Fatalf("max_tokens = %+v, want >= 2048 for deepseek on opencode", req.MaxTokens)
		}
		_, _ = w.Write([]byte(`{"choices":[{"message":{"content":"hello"},"finish_reason":"stop"}]}`))
	}))
	defer server.Close()

	p := NewOpenAICompatible(enum.ProviderOpenCode, server.URL)
	maxTokens := 256
	result, err := p.GenerateText(context.Background(), domai.GenerateRequest{
		Provider:   enum.ProviderOpenCode,
		Model:      "deepseek-v4-flash",
		Credential: domai.Credential{APIKey: "test-token"},
		Messages:   []domai.Message{{Role: "user", Content: "hi"}},
		MaxTokens:  &maxTokens,
	})
	if err != nil {
		t.Fatalf("GenerateText() error = %v", err)
	}
	if result.Text != "hello" || result.FinishReason != "stop" {
		t.Fatalf("result = %+v, want text=hello finish_reason=stop", result)
	}
}

func TestOpenAICompatible_GenerateText_FallsBackToReasoningContent(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = w.Write([]byte(`{"choices":[{"message":{"content":"","reasoning_content":"thinking only"},"finish_reason":"length"}]}`))
	}))
	defer server.Close()

	p := NewOpenAICompatible(enum.ProviderXAI, server.URL)
	result, err := p.GenerateText(context.Background(), domai.GenerateRequest{
		Model:      "deepseek-test",
		Credential: domai.Credential{APIKey: "test-token"},
		Messages:   []domai.Message{{Role: "user", Content: "hi"}},
	})
	if err != nil {
		t.Fatalf("GenerateText() error = %v", err)
	}
	if result.Text != "thinking only" {
		t.Fatalf("result.Text = %q, want thinking only", result.Text)
	}
}

func TestOpenAICompatible_StreamText_ParsesReasoningContent(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "text/event-stream")
		_, _ = w.Write([]byte("data: {\"choices\":[{\"delta\":{\"reasoning_content\":\"think\"}}]}\n\n"))
		_, _ = w.Write([]byte("data: {\"choices\":[{\"delta\":{\"content\":\"answer\"},\"finish_reason\":\"stop\"}]}\n\n"))
		_, _ = w.Write([]byte("data: [DONE]\n\n"))
	}))
	defer server.Close()

	p := NewOpenAICompatible(enum.ProviderXAI, server.URL)
	stream, err := p.StreamText(context.Background(), domai.GenerateRequest{
		Model:      "deepseek-test",
		Credential: domai.Credential{APIKey: "test-token"},
		Messages:   []domai.Message{{Role: "user", Content: "hi"}},
	})
	if err != nil {
		t.Fatalf("StreamText() error = %v", err)
	}

	var deltas []string
	var finishReason string
	for event := range stream {
		switch event.Type {
		case "delta":
			deltas = append(deltas, event.Text)
		case "done":
			finishReason = event.FinishReason
		case "error":
			t.Fatalf("stream error: %s", event.Error)
		}
	}

	if strings.Join(deltas, "") != "thinkanswer" {
		t.Fatalf("deltas = %v, want thinkanswer", deltas)
	}
	if finishReason != "stop" {
		t.Fatalf("finishReason = %q, want stop", finishReason)
	}
}

func TestBuildChatCompletionRequest_DisablesThinkingForOpenCodeDeepSeek(t *testing.T) {
	p := NewOpenAICompatible(enum.ProviderOpenCode, "https://example.com")
	maxTokens := 128
	body := p.buildChatCompletionRequest(domai.GenerateRequest{
		Provider:  enum.ProviderOpenCode,
		Model:     "deepseek-v4-flash",
		Messages:  []domai.Message{{Role: "user", Content: "hi"}},
		MaxTokens: &maxTokens,
	}, true)

	if body.Thinking == nil || body.Thinking.Type != "disabled" {
		t.Fatalf("thinking = %+v, want disabled", body.Thinking)
	}
	if body.MaxTokens == nil || *body.MaxTokens < 2048 {
		t.Fatalf("max_tokens = %+v, want >= 2048", body.MaxTokens)
	}
}

func TestExtractAssistantText_ContentArray(t *testing.T) {
	msg := assistantMessage{
		Content: json.RawMessage(`[{"type":"text","text":"array content"}]`),
	}
	if got := extractAssistantText(msg); got != "array content" {
		t.Fatalf("extractAssistantText() = %q, want array content", got)
	}
}