package ai

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

	"gitea.oblak.solutions/dimitar/gitFlow/internal/config"
	"gitea.oblak.solutions/dimitar/gitFlow/pkg/status"
)

func sampleResult() status.ScanResult {
	return status.ScanResult{
		ScannedAt: time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC),
		ParentDir: "/home/user/projects",
		Repos: []status.RepoInfo{
			{Path: "/home/user/projects/api", Name: "api", Branch: "main", Status: status.StatusClean},
			{Path: "/home/user/projects/web", Name: "web", Branch: "feat/login", Status: status.StatusModified, ModifiedFiles: []string{"a.go"}},
			{Path: "/home/user/projects/lib", Name: "lib", Branch: "main", Status: status.StatusBehind, BehindBy: 5},
		},
	}
}

func suggestionsJSON() string {
	return `[{"repo_path":"/home/user/projects/web","action":"commit","message":"commit your changes","command":"git add -A && git commit -m wip","priority":2},
	{"repo_path":"/home/user/projects/lib","action":"pull","message":"pull latest","command":"git pull","priority":1}]`
}

func TestNewProviderOpenAIRequiresKey(t *testing.T) {
	t.Setenv("GITFLOW_TEST_AI_KEY", "")
	if _, err := NewProvider(config.AIConfig{Provider: "openai", APIKeyEnv: "GITFLOW_TEST_AI_KEY"}); err == nil {
		t.Error("NewProvider(openai, no key) succeeded, want error")
	}
}

func TestNewProviderAnthropicRequiresKey(t *testing.T) {
	t.Setenv("GITFLOW_TEST_AI_KEY", "")
	if _, err := NewProvider(config.AIConfig{Provider: "anthropic", APIKeyEnv: "GITFLOW_TEST_AI_KEY"}); err == nil {
		t.Error("NewProvider(anthropic, no key) succeeded, want error")
	}
}

func TestNewProviderOllamaNeedsNoKey(t *testing.T) {
	p, err := NewProvider(config.AIConfig{Provider: "ollama"})
	if err != nil {
		t.Fatalf("NewProvider(ollama): %v", err)
	}
	if p.Name() != "ollama" {
		t.Errorf("Name = %q, want ollama", p.Name())
	}
}

func TestNewProviderUnknown(t *testing.T) {
	if _, err := NewProvider(config.AIConfig{Provider: "magic"}); err == nil {
		t.Error("NewProvider(magic) succeeded, want error")
	}
}

func TestOpenAIProvider(t *testing.T) {
	var gotReq chatRequest
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if got := r.Header.Get("Authorization"); got != "Bearer test-key" {
			t.Errorf("Authorization = %q, want Bearer test-key", got)
		}
		if got := r.URL.Path; got != "/chat/completions" {
			t.Errorf("path = %q, want /chat/completions", got)
		}
		if err := json.NewDecoder(r.Body).Decode(&gotReq); err != nil {
			t.Fatal(err)
		}
		w.Header().Set("Content-Type", "application/json")
		content := "```json\n" + suggestionsJSON() + "\n```"
		resp, _ := json.Marshal(map[string]any{
			"choices": []any{map[string]any{
				"message": map[string]any{"role": "assistant", "content": content},
			}},
		})
		_, _ = w.Write(resp)
	}))
	defer srv.Close()

	p := NewOpenAI(config.AIConfig{BaseURL: srv.URL, Model: "gpt-test"}, "test-key")
	sugs, err := p.Suggest(context.Background(), sampleResult())
	if err != nil {
		t.Fatalf("Suggest: %v", err)
	}
	if gotReq.Model != "gpt-test" {
		t.Errorf("model = %q, want gpt-test", gotReq.Model)
	}
	if len(gotReq.Messages) != 2 || gotReq.Messages[0].Role != "system" {
		t.Errorf("messages malformed: %+v", gotReq.Messages)
	}
	if len(sugs) != 2 {
		t.Fatalf("got %d suggestions, want 2", len(sugs))
	}
	if sugs[0].Action != "commit" || sugs[0].Priority != 2 || sugs[0].RepoPath != "/home/user/projects/web" {
		t.Errorf("suggestion[0] = %+v", sugs[0])
	}
}

func TestOpenAIProviderErrorBody(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"error":{"message":"insufficient quota"}}`))
	}))
	defer srv.Close()

	p := NewOpenAI(config.AIConfig{BaseURL: srv.URL, Model: "gpt-test"}, "k")
	if _, err := p.Suggest(context.Background(), sampleResult()); err == nil {
		t.Error("Suggest succeeded with API error body, want error")
	}
}

func TestOpenAIProviderHTTPFailure(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, "boom", http.StatusInternalServerError)
	}))
	defer srv.Close()

	p := NewOpenAI(config.AIConfig{BaseURL: srv.URL, Model: "gpt-test"}, "k")
	if _, err := p.Suggest(context.Background(), sampleResult()); err == nil {
		t.Error("Suggest succeeded with 500, want error")
	}
}

func TestOllamaProvider(t *testing.T) {
	var gotReq ollamaRequest
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if got := r.URL.Path; got != "/api/chat" {
			t.Errorf("path = %q, want /api/chat", got)
		}
		if err := json.NewDecoder(r.Body).Decode(&gotReq); err != nil {
			t.Fatal(err)
		}
		resp, _ := json.Marshal(map[string]any{
			"message": map[string]any{"role": "assistant", "content": suggestionsJSON()},
			"error":   "",
		})
		_, _ = w.Write(resp)
	}))
	defer srv.Close()

	p := NewOllama(config.AIConfig{BaseURL: srv.URL, Model: "llama-test"})
	sugs, err := p.Suggest(context.Background(), sampleResult())
	if err != nil {
		t.Fatalf("Suggest: %v", err)
	}
	if gotReq.Model != "llama-test" || gotReq.Format != "json" || gotReq.Stream {
		t.Errorf("request malformed: %+v", gotReq)
	}
	if len(sugs) != 2 {
		t.Errorf("got %d suggestions, want 2", len(sugs))
	}
}

func TestOllamaProviderErrorField(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = w.Write([]byte(`{"error":"model not found"}`))
	}))
	defer srv.Close()

	p := NewOllama(config.AIConfig{BaseURL: srv.URL})
	if _, err := p.Suggest(context.Background(), sampleResult()); err == nil {
		t.Error("Suggest succeeded with error field, want error")
	}
}

func TestAnthropicProvider(t *testing.T) {
	var gotReq anthropicRequest
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if got := r.Header.Get("x-api-key"); got != "test-key" {
			t.Errorf("x-api-key = %q", got)
		}
		if got := r.Header.Get("anthropic-version"); got != anthropicVersion {
			t.Errorf("anthropic-version = %q", got)
		}
		if err := json.NewDecoder(r.Body).Decode(&gotReq); err != nil {
			t.Fatal(err)
		}
		resp, _ := json.Marshal(map[string]any{
			"content": []any{map[string]any{"type": "text", "text": suggestionsJSON()}},
		})
		_, _ = w.Write(resp)
	}))
	defer srv.Close()

	p := NewAnthropic(config.AIConfig{BaseURL: srv.URL, Model: "claude-test"}, "test-key")
	sugs, err := p.Suggest(context.Background(), sampleResult())
	if err != nil {
		t.Fatalf("Suggest: %v", err)
	}
	if gotReq.MaxTokens != 1024 || gotReq.System == "" {
		t.Errorf("request malformed: %+v", gotReq)
	}
	if len(sugs) != 2 {
		t.Errorf("got %d suggestions, want 2", len(sugs))
	}
}

func TestParseSuggestions(t *testing.T) {
	plain := `[{"repo_path":"/a","action":"push","message":"m","command":"git push","priority":2}]`
	if got, err := parseSuggestions(plain); err != nil || len(got) != 1 {
		t.Errorf("plain: got %v, err %v", got, err)
	}

	fenced := "Here you go:\n```json\n" + plain + "\n```\nHope that helps!"
	if got, err := parseSuggestions(fenced); err != nil || len(got) != 1 {
		t.Errorf("fenced: got %v, err %v", got, err)
	}

	if got, err := parseSuggestions("[]"); err != nil || len(got) != 0 {
		t.Errorf("empty: got %v, err %v", got, err)
	}

	if _, err := parseSuggestions("no json here"); err == nil {
		t.Error("garbage accepted, want error")
	}

	bad := `[{"repo_path":` // truncated JSON
	if _, err := parseSuggestions(bad); err == nil {
		t.Error("truncated JSON accepted, want error")
	}
}

func TestParseSuggestionsClampsPriority(t *testing.T) {
	out, err := parseSuggestions(`[{"priority":7},{"priority":-3},{"priority":1}]`)
	if err != nil {
		t.Fatal(err)
	}
	want := []int{2, 0, 1}
	for i, w := range want {
		if out[i].Priority != w {
			t.Errorf("suggestion[%d] priority = %d, want %d", i, out[i].Priority, w)
		}
	}
}

func TestBuildPrompt(t *testing.T) {
	prompt := BuildPrompt(sampleResult())
	for _, want := range []string{
		`"/home/user/projects"`, "api", "web", "lib", "feat/login",
		"repo_path", "priority", "Return ONLY a JSON array",
	} {
		if !strings.Contains(prompt, want) {
			t.Errorf("prompt missing %q", want)
		}
	}
	if strings.Contains(prompt, "\x00") {
		t.Error("prompt contains NUL bytes")
	}
}

// TestProviderHonorsCancellation ensures a cancelled context fails fast
// instead of waiting for the upstream.
func TestProviderHonorsCancellation(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	cancel()
	p := NewOpenAI(config.AIConfig{BaseURL: "http://127.0.0.1:1"}, "k")
	if _, err := p.Suggest(ctx, sampleResult()); err == nil {
		t.Error("Suggest(cancelled ctx) succeeded, want error")
	}
}