package llm

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"os"
	"strings"
	"testing"
	"time"
)

func TestBuildOllamaRequest_OptionsAndStream(t *testing.T) {
	o := Options{Model: "codemodel", Temperature: 0, MaxTokens: 256, Stop: []string{"STOP"}}
	msgs := []Message{{Role: "user", Content: "hello"}}
	req := buildOllamaRequest(o, msgs, f64p(0.2), false)
	if req.Model != "codemodel" || req.Stream {
		t.Fatalf("model/stream mismatch: %+v", req)
	}
	if req.Options == nil {
		t.Fatalf("expected options map")
	}
	if req.Options.(map[string]any)["temperature"].(float64) != 0.2 {
		t.Fatalf("default temp not applied")
	}
	if req.Options.(map[string]any)["num_predict"].(int) != 256 {
		t.Fatalf("num_predict not applied")
	}
	if req.Options.(map[string]any)["stop"].([]string)[0] != "STOP" {
		t.Fatalf("stop not applied")
	}

	req2 := buildOllamaRequest(o, msgs, f64p(0.2), true)
	if !req2.Stream {
		t.Fatalf("expected stream=true")
	}
}

func TestBuildOllamaRequest_TempOverride(t *testing.T) {
	o := Options{Model: "m", Temperature: 0.9}
	msgs := []Message{{Role: "user", Content: "hi"}}
	req := buildOllamaRequest(o, msgs, f64p(0.2), false)
	m := req.Options.(map[string]any)
	if m["temperature"].(float64) != 0.9 {
		t.Fatalf("explicit temp should override default")
	}
}

func TestOllama_NameAndModel(t *testing.T) {
	c := newOllama("http://x", "model-x", nil).(ollamaClient)
	if c.Name() != "ollama" {
		t.Fatalf("name: %q", c.Name())
	}
	if c.DefaultModel() != "model-x" {
		t.Fatalf("default model: %q", c.DefaultModel())
	}
}

func TestOllamaChat_Success(t *testing.T) {
	if os.Getenv("HEXAI_TEST_SKIP_NET") == "1" {
		t.Skip("skip network-bound tests in restricted environments")
	}
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost || r.URL.Path != "/api/chat" {
			t.Fatalf("unexpected request: %s %s", r.Method, r.URL.Path)
		}
		w.Header().Set("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(map[string]any{"message": map[string]string{"role": "assistant", "content": "Hello"}, "done": true})
	}))
	defer ts.Close()
	c := newOllama(ts.URL, "m", f64p(0.1)).(ollamaClient)
	c.httpClient = ts.Client()
	out, err := c.Chat(context.Background(), []Message{{Role: "user", Content: "hi"}})
	if err != nil {
		t.Fatalf("unexpected err: %v", err)
	}
	if out != "Hello" {
		t.Fatalf("got %q", out)
	}
}

func TestOllamaChat_EmptyContent(t *testing.T) {
	if os.Getenv("HEXAI_TEST_SKIP_NET") == "1" {
		t.Skip("skip network-bound tests in restricted environments")
	}
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_ = json.NewEncoder(w).Encode(map[string]any{"message": map[string]string{"role": "assistant", "content": ""}, "done": true})
	}))
	defer ts.Close()
	c := newOllama(ts.URL, "m", nil).(ollamaClient)
	c.httpClient = ts.Client()
	if _, err := c.Chat(context.Background(), []Message{{Role: "user", Content: "x"}}); err == nil {
		t.Fatalf("expected error for empty content")
	}
}

func TestOllamaChat_Non2xx(t *testing.T) {
	if os.Getenv("HEXAI_TEST_SKIP_NET") == "1" {
		t.Skip("skip network-bound tests in restricted environments")
	}
	// API error string
	ts1 := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(400)
		_ = json.NewEncoder(w).Encode(map[string]any{"error": "bad"})
	}))
	defer ts1.Close()
	c1 := newOllama(ts1.URL, "m", nil).(ollamaClient)
	c1.httpClient = ts1.Client()
	if _, err := c1.Chat(context.Background(), []Message{{Role: "user", Content: "x"}}); err == nil {
		t.Fatalf("expected error for 400 with api body")
	}
	// Plain HTTP error without api message
	ts2 := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(500)
		_, _ = w.Write([]byte("{}"))
	}))
	defer ts2.Close()
	c2 := newOllama(ts2.URL, "m", nil).(ollamaClient)
	c2.httpClient = ts2.Client()
	if _, err := c2.Chat(context.Background(), []Message{{Role: "user", Content: "x"}}); err == nil {
		t.Fatalf("expected error for 500")
	}
}

type rtFunc func(*http.Request) (*http.Response, error)

func (f rtFunc) RoundTrip(r *http.Request) (*http.Response, error) { return f(r) }

func TestOllamaChat_HTTPError(t *testing.T) {
	c := newOllama("http://127.0.0.1:0", "m", nil).(ollamaClient)
	c.httpClient = &http.Client{Transport: rtFunc(func(*http.Request) (*http.Response, error) { return nil, fmt.Errorf("boom") })}
	if _, err := c.Chat(context.Background(), []Message{{Role: "user", Content: "x"}}); err == nil {
		t.Fatalf("expected http error path")
	}
}

func TestOllamaChat_DecodeError(t *testing.T) {
	if os.Getenv("HEXAI_TEST_SKIP_NET") == "1" {
		t.Skip("skip network-bound tests in restricted environments")
	}
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = w.Write([]byte("{bad json}"))
	}))
	defer ts.Close()
	c := newOllama(ts.URL, "m", nil).(ollamaClient)
	c.httpClient = ts.Client()
	if _, err := c.Chat(context.Background(), []Message{{Role: "user", Content: "x"}}); err == nil {
		t.Fatalf("expected decode error")
	}
}

func TestHandleOllamaNon2xx_OK(t *testing.T) {
	resp := &http.Response{StatusCode: 200, Body: ioNopCloser(strings.NewReader(""))}
	if err := handleOllamaNon2xx(resp, time.Now()); err != nil {
		t.Fatalf("unexpected: %v", err)
	}
}

func TestOllamaChatStream_Success(t *testing.T) {
	if os.Getenv("HEXAI_TEST_SKIP_NET") == "1" {
		t.Skip("skip network-bound tests in restricted environments")
	}
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		// two JSON objects back-to-back
		_, _ = w.Write([]byte(`{"message":{"role":"assistant","content":"Hi"},"done":false}`))
		_, _ = w.Write([]byte(`{"message":{"role":"assistant","content":"!"},"done":true}`))
	}))
	defer ts.Close()
	c := newOllama(ts.URL, "m", nil).(ollamaClient)
	c.httpClient = ts.Client()
	var got strings.Builder
	if err := c.ChatStream(context.Background(), []Message{{Role: "user", Content: "x"}}, func(s string) { got.WriteString(s) }); err != nil {
		t.Fatalf("unexpected: %v", err)
	}
	if got.String() != "Hi!" {
		t.Fatalf("got %q", got.String())
	}
}

func TestOllamaChatStream_ErrorEvent(t *testing.T) {
	if os.Getenv("HEXAI_TEST_SKIP_NET") == "1" {
		t.Skip("skip network-bound tests in restricted environments")
	}
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_ = json.NewEncoder(w).Encode(map[string]any{"error": "oops"})
	}))
	defer ts.Close()
	c := newOllama(ts.URL, "m", nil).(ollamaClient)
	c.httpClient = ts.Client()
	if err := c.ChatStream(context.Background(), []Message{{Role: "user", Content: "x"}}, func(string) {}); err == nil {
		t.Fatalf("expected stream error")
	}
}

func TestOllamaChatStream_DecodeError(t *testing.T) {
	if os.Getenv("HEXAI_TEST_SKIP_NET") == "1" {
		t.Skip("skip network-bound tests in restricted environments")
	}
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = w.Write([]byte("{not json}"))
	}))
	defer ts.Close()
	c := newOllama(ts.URL, "m", nil).(ollamaClient)
	c.httpClient = ts.Client()
	if err := c.ChatStream(context.Background(), []Message{{Role: "user", Content: "x"}}, func(string) {}); err == nil {
		t.Fatalf("expected decode error")
	}
}

// small helper to construct an io.ReadCloser without importing extra packages
type readCloser struct{ *strings.Reader }

func (readCloser) Close() error                 { return nil }
func ioNopCloser(r *strings.Reader) *readCloser { return &readCloser{r} }