package server

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

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

	// Put T08 in ready first
	os.Rename(
		filepath.Join(srv.Config.TasksDir, "backlog", "T08.md"),
		filepath.Join(srv.Config.TasksDir, "ready", "T08.md"),
	)

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

	if w.Code != http.StatusForbidden {
		t.Fatalf("expected 403 for ready→active, got %d: %s", w.Code, w.Body.String())
	}
}

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

	// Put T08 in active
	os.Rename(
		filepath.Join(srv.Config.TasksDir, "backlog", "T08.md"),
		filepath.Join(srv.Config.TasksDir, "active", "T08.md"),
	)

	// Try to move active → review (agent-only)
	req := httptest.NewRequest(http.MethodPost, "/api/task/T08/move?to=review", nil)
	w := httptest.NewRecorder()
	srv.Router.ServeHTTP(w, req)

	if w.Code != http.StatusForbidden {
		t.Fatalf("expected 403 for active→review, got %d: %s", w.Code, w.Body.String())
	}
}

func TestAPIMoveTask_AllowedBacklogToReady(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 for backlog→ready, got %d: %s", w.Code, w.Body.String())
	}
}

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

	// Put T08 in review
	os.Rename(
		filepath.Join(srv.Config.TasksDir, "backlog", "T08.md"),
		filepath.Join(srv.Config.TasksDir, "review", "T08.md"),
	)

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

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

func TestAPIMoveTask_AddsTimestamp(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)

	content, _ := os.ReadFile(filepath.Join(srv.Config.TasksDir, "ready", "T08.md"))
	text := string(content)
	if !containsStr(text, "Odobren (→ready)") {
		t.Error("expected timestamp in API-moved task file")
	}
}