package server

import (
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"

	"github.com/dal/kaos/internal/config"
)

const testTask1 = `# T01: Prvi task

**Agent:** coder
**Model:** Sonnet
**Zavisi od:** —

---

## Opis

Opis prvog taska.

---
`

const testTask2 = `# T08: HTTP server

**Agent:** coder
**Model:** Sonnet
**Zavisi od:** T07

---

## Opis

Implementacija HTTP servera.

---
`

func setupTestServer(t *testing.T) *Server {
	t.Helper()
	dir := t.TempDir()

	tasksDir := filepath.Join(dir, "TASKS")
	for _, folder := range []string{"backlog", "ready", "active", "review", "done", "reports"} {
		os.MkdirAll(filepath.Join(tasksDir, folder), 0755)
	}

	os.WriteFile(filepath.Join(tasksDir, "done", "T01.md"), []byte(testTask1), 0644)
	os.WriteFile(filepath.Join(tasksDir, "backlog", "T08.md"), []byte(testTask2), 0644)

	cfg := &config.Config{
		TasksDir:    tasksDir,
		ProjectPath: dir,
		Port:        "0",
	}

	return New(cfg)
}

func TestAPIGetTasks(t *testing.T) {
	srv := setupTestServer(t)

	req := httptest.NewRequest(http.MethodGet, "/api/tasks", nil)
	w := httptest.NewRecorder()
	srv.Router.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	var tasks []taskResponse
	if err := json.Unmarshal(w.Body.Bytes(), &tasks); err != nil {
		t.Fatalf("invalid JSON: %v", err)
	}

	if len(tasks) != 2 {
		t.Fatalf("expected 2 tasks, got %d", len(tasks))
	}

	// Check that tasks have correct statuses
	statuses := map[string]string{}
	for _, task := range tasks {
		statuses[task.ID] = task.Status
	}
	if statuses["T01"] != "done" {
		t.Errorf("expected T01 status done, got %s", statuses["T01"])
	}
	if statuses["T08"] != "backlog" {
		t.Errorf("expected T08 status backlog, got %s", statuses["T08"])
	}
}

func TestAPIGetTask(t *testing.T) {
	srv := setupTestServer(t)

	req := httptest.NewRequest(http.MethodGet, "/api/task/T01", nil)
	w := httptest.NewRecorder()
	srv.Router.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}

	var detail taskDetailResponse
	if err := json.Unmarshal(w.Body.Bytes(), &detail); err != nil {
		t.Fatalf("invalid JSON: %v", err)
	}

	if detail.ID != "T01" {
		t.Errorf("expected T01, got %s", detail.ID)
	}
	if detail.Content == "" {
		t.Error("expected non-empty content")
	}
}

func TestAPIGetTask_NotFound(t *testing.T) {
	srv := setupTestServer(t)

	req := httptest.NewRequest(http.MethodGet, "/api/task/T99", nil)
	w := httptest.NewRecorder()
	srv.Router.ServeHTTP(w, req)

	if w.Code != http.StatusNotFound {
		t.Fatalf("expected 404, got %d", w.Code)
	}
}

func TestAPIMoveTask(t *testing.T) {
	srv := setupTestServer(t)

	req := httptest.NewRequest(http.MethodPost, "/api/task/T08/move?to=ready", nil)
	w := httptest.NewRecorder()
	srv.Router.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	// Verify file was moved
	if _, err := os.Stat(filepath.Join(srv.Config.TasksDir, "ready", "T08.md")); err != nil {
		t.Error("expected T08.md in ready/")
	}
	if _, err := os.Stat(filepath.Join(srv.Config.TasksDir, "backlog", "T08.md")); !os.IsNotExist(err) {
		t.Error("expected T08.md removed from backlog/")
	}
}

func TestAPIMoveTask_NotFound(t *testing.T) {
	srv := setupTestServer(t)

	req := httptest.NewRequest(http.MethodPost, "/api/task/T99/move?to=ready", nil)
	w := httptest.NewRecorder()
	srv.Router.ServeHTTP(w, req)

	if w.Code != http.StatusNotFound {
		t.Fatalf("expected 404, got %d", w.Code)
	}
}

func TestAPIMoveTask_InvalidFolder(t *testing.T) {
	srv := setupTestServer(t)

	req := httptest.NewRequest(http.MethodPost, "/api/task/T08/move?to=invalid", nil)
	w := httptest.NewRecorder()
	srv.Router.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d", w.Code)
	}
}

func TestDashboardHTML(t *testing.T) {
	srv := setupTestServer(t)

	req := httptest.NewRequest(http.MethodGet, "/", nil)
	w := httptest.NewRecorder()
	srv.Router.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}

	body := w.Body.String()
	if !containsStr(body, "KAOS Dashboard") {
		t.Error("expected 'KAOS Dashboard' in HTML")
	}
	if !containsStr(body, "T01") {
		t.Error("expected T01 in HTML")
	}
	if !containsStr(body, "T08") {
		t.Error("expected T08 in HTML")
	}
	if !containsStr(body, "BACKLOG") {
		t.Error("expected BACKLOG column in HTML")
	}
	if !containsStr(body, "DONE") {
		t.Error("expected DONE column in HTML")
	}
}

func TestTaskDetailHTML(t *testing.T) {
	srv := setupTestServer(t)

	req := httptest.NewRequest(http.MethodGet, "/task/T01", nil)
	w := httptest.NewRecorder()
	srv.Router.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}

	body := w.Body.String()
	if !containsStr(body, "T01") {
		t.Error("expected T01 in detail HTML")
	}
	if !containsStr(body, "Prvi task") {
		t.Error("expected task title in detail HTML")
	}
}

func TestTaskDetailHTML_NotFound(t *testing.T) {
	srv := setupTestServer(t)

	req := httptest.NewRequest(http.MethodGet, "/task/T99", nil)
	w := httptest.NewRecorder()
	srv.Router.ServeHTTP(w, req)

	if w.Code != http.StatusNotFound {
		t.Fatalf("expected 404, got %d", w.Code)
	}
}

func TestHTMLMoveTask(t *testing.T) {
	srv := setupTestServer(t)

	req := httptest.NewRequest(http.MethodPost, "/task/T08/move?to=ready", nil)
	w := httptest.NewRecorder()
	srv.Router.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	// Should return updated dashboard HTML
	body := w.Body.String()
	if !containsStr(body, "KAOS Dashboard") {
		t.Error("expected dashboard HTML after move")
	}
}

func containsStr(s, substr string) bool {
	return len(s) >= len(substr) && findStr(s, substr)
}

func findStr(s, substr string) bool {
	for i := 0; i <= len(s)-len(substr); i++ {
		if s[i:i+len(substr)] == substr {
			return true
		}
	}
	return false
}