package httpapi

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"tutor/internal/config"
	"tutor/internal/interview"
	"tutor/internal/learnermemory"
	"tutor/internal/ontology"
	"tutor/internal/progression"
	"tutor/internal/teachingassets"
	"tutor/internal/workflows"
)

func TestUploadMaterialMarkdown(t *testing.T) {
	memory := learnermemory.NewService(learnermemory.NewMemoryStore())
	service := interview.NewService(interview.NewMemoryStore(), workflows.NewStubRunner(), memory)
	progress := progression.NewService(memory)
	onto := ontology.NewService(ontology.NewMemoryStore())
	assets := teachingassets.NewService(teachingassets.NewMemoryStore(), onto, "gpt-image-v2")
	handler := NewHandler(config.Config{Environment: "test"}, service, memory, progress, onto, assets)
	routes := handler.Routes()

	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)
	part, _ := w.CreateFormFile("file", "notes.md")
	io.Copy(part, strings.NewReader("# Backend notes\nIdempotent API retries need transactions."))
	w.Close()

	req := httptest.NewRequest(http.MethodPost, "/api/v1/materials/upload", &buf)
	req.Header.Set("Content-Type", w.FormDataContentType())
	rec := httptest.NewRecorder()
	routes.ServeHTTP(rec, req)

	if rec.Code != http.StatusCreated {
		t.Fatalf("status = %d, body = %s", rec.Code, rec.Body.String())
	}

	var result ontology.IngestResult
	decodeJSON(t, rec.Body, &result)
	if len(result.Snapshot.Concepts) == 0 {
		t.Fatal("expected concept candidates after md upload")
	}
}

func TestUploadMaterialPDF(t *testing.T) {
	memory := learnermemory.NewService(learnermemory.NewMemoryStore())
	service := interview.NewService(interview.NewMemoryStore(), workflows.NewStubRunner(), memory)
	progress := progression.NewService(memory)
	onto := ontology.NewService(ontology.NewMemoryStore())
	assets := teachingassets.NewService(teachingassets.NewMemoryStore(), onto, "gpt-image-v2")
	handler := NewHandler(config.Config{Environment: "test"}, service, memory, progress, onto, assets)
	routes := handler.Routes()

	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)
	part, _ := w.CreateFormFile("file", "notes.pdf")
	io.Copy(part, strings.NewReader("not a real pdf"))
	w.Close()

	req := httptest.NewRequest(http.MethodPost, "/api/v1/materials/upload", &buf)
	req.Header.Set("Content-Type", w.FormDataContentType())
	rec := httptest.NewRecorder()
	routes.ServeHTTP(rec, req)

	if rec.Code != http.StatusInternalServerError {
		t.Fatalf("expected 500 for invalid PDF, got %d: %s", rec.Code, rec.Body.String())
	}
}

func TestUploadMaterialUnsupportedFormat(t *testing.T) {
	memory := learnermemory.NewService(learnermemory.NewMemoryStore())
	service := interview.NewService(interview.NewMemoryStore(), workflows.NewStubRunner(), memory)
	progress := progression.NewService(memory)
	onto := ontology.NewService(ontology.NewMemoryStore())
	assets := teachingassets.NewService(teachingassets.NewMemoryStore(), onto, "gpt-image-v2")
	handler := NewHandler(config.Config{Environment: "test"}, service, memory, progress, onto, assets)
	routes := handler.Routes()

	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)
	part, _ := w.CreateFormFile("file", "notes.txt")
	io.Copy(part, strings.NewReader("plain text"))
	w.Close()

	req := httptest.NewRequest(http.MethodPost, "/api/v1/materials/upload", &buf)
	req.Header.Set("Content-Type", w.FormDataContentType())
	rec := httptest.NewRecorder()
	routes.ServeHTTP(rec, req)

	if rec.Code != http.StatusBadRequest {
		t.Fatalf("expected 400 for unsupported format, got %d: %s", rec.Code, rec.Body.String())
	}
}

func TestUploadMaterialMissingFile(t *testing.T) {
	memory := learnermemory.NewService(learnermemory.NewMemoryStore())
	service := interview.NewService(interview.NewMemoryStore(), workflows.NewStubRunner(), memory)
	progress := progression.NewService(memory)
	onto := ontology.NewService(ontology.NewMemoryStore())
	assets := teachingassets.NewService(teachingassets.NewMemoryStore(), onto, "gpt-image-v2")
	handler := NewHandler(config.Config{Environment: "test"}, service, memory, progress, onto, assets)
	routes := handler.Routes()

	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)
	w.Close()

	req := httptest.NewRequest(http.MethodPost, "/api/v1/materials/upload", &buf)
	req.Header.Set("Content-Type", w.FormDataContentType())
	rec := httptest.NewRecorder()
	routes.ServeHTTP(rec, req)

	if rec.Code != http.StatusBadRequest {
		t.Fatalf("expected 400 for missing file, got %d: %s", rec.Code, rec.Body.String())
	}
}

func TestUploadMaterialWithCustomTitle(t *testing.T) {
	memory := learnermemory.NewService(learnermemory.NewMemoryStore())
	service := interview.NewService(interview.NewMemoryStore(), workflows.NewStubRunner(), memory)
	progress := progression.NewService(memory)
	onto := ontology.NewService(ontology.NewMemoryStore())
	assets := teachingassets.NewService(teachingassets.NewMemoryStore(), onto, "gpt-image-v2")
	handler := NewHandler(config.Config{Environment: "test"}, service, memory, progress, onto, assets)
	routes := handler.Routes()

	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)
	w.WriteField("title", "Custom Title")
	part, _ := w.CreateFormFile("file", "notes.md")
	io.Copy(part, strings.NewReader("Cache invalidation with TTL."))
	w.Close()

	req := httptest.NewRequest(http.MethodPost, "/api/v1/materials/upload", &buf)
	req.Header.Set("Content-Type", w.FormDataContentType())
	rec := httptest.NewRecorder()
	routes.ServeHTTP(rec, req)

	if rec.Code != http.StatusCreated {
		t.Fatalf("status = %d, body = %s", rec.Code, rec.Body.String())
	}

	var result ontology.IngestResult
	decodeJSON(t, rec.Body, &result)
	if result.Material.Title != "Custom Title" {
		t.Fatalf("title = %q, want %q", result.Material.Title, "Custom Title")
	}
}

func TestUploadMaterialOntologyNotConfigured(t *testing.T) {
	handler := NewHandler(config.Config{Environment: "test"}, nil, nil, nil, nil, nil)
	routes := handler.Routes()

	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)
	part, _ := w.CreateFormFile("file", "notes.md")
	io.Copy(part, strings.NewReader("# test"))
	w.Close()

	req := httptest.NewRequest(http.MethodPost, "/api/v1/materials/upload", &buf)
	req.Header.Set("Content-Type", w.FormDataContentType())
	rec := httptest.NewRecorder()
	routes.ServeHTTP(rec, req)

	if rec.Code != http.StatusNotFound {
		t.Fatalf("expected 404, got %d: %s", rec.Code, rec.Body.String())
	}
}

func decodeJSON(t *testing.T, r io.Reader, v interface{}) {
	t.Helper()
	if err := json.NewDecoder(r).Decode(v); err != nil {
		t.Fatalf("decode error: %v", err)
	}
}

func TestUploadMaterialMarkdownFrontmatter(t *testing.T) {
	memory := learnermemory.NewService(learnermemory.NewMemoryStore())
	service := interview.NewService(interview.NewMemoryStore(), workflows.NewStubRunner(), memory)
	progress := progression.NewService(memory)
	onto := ontology.NewService(ontology.NewMemoryStore())
	assets := teachingassets.NewService(teachingassets.NewMemoryStore(), onto, "gpt-image-v2")
	handler := NewHandler(config.Config{Environment: "test"}, service, memory, progress, onto, assets)
	routes := handler.Routes()

	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)
	part, _ := w.CreateFormFile("file", "study-notes.md")
	io.Copy(part, strings.NewReader(fmt.Sprintf("---\ntitle: Study Notes\ntags:\n  - backend\n  - go\n---\n\n# HTTP Idempotency\n\nIdempotent API retries need transactions for correctness.")))
	w.Close()

	req := httptest.NewRequest(http.MethodPost, "/api/v1/materials/upload", &buf)
	req.Header.Set("Content-Type", w.FormDataContentType())
	rec := httptest.NewRecorder()
	routes.ServeHTTP(rec, req)

	if rec.Code != http.StatusCreated {
		t.Fatalf("status = %d, body = %s", rec.Code, rec.Body.String())
	}

	var result ontology.IngestResult
	decodeJSON(t, rec.Body, &result)
	if len(result.Snapshot.Concepts) == 0 {
		t.Fatal("expected concepts from markdown with frontmatter")
	}
	for _, c := range result.Snapshot.Concepts {
		if c.Concept.ID == "http-idempotency" {
			return
		}
	}
	t.Fatalf("expected http-idempotency concept, got concepts: %v", result.Snapshot.Concepts)
}