package httpapi

import (
	"bytes"
	"encoding/json"
	"mime/multipart"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"
)

func TestCreateScratchTTLQueryOmitUsesDefault(t *testing.T) {
	t.Parallel()

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      15 * time.Minute,
		rateLimitEnable: false,
	})

	before := time.Now().UTC()
	req := httptest.NewRequest(http.MethodPost, "/api/scratch", bytes.NewBufferString("omit-ttl"))
	req.Header.Set("Content-Type", "text/plain; charset=utf-8")
	req.RemoteAddr = "127.0.0.1:8101"
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)
	if rec.Code != http.StatusCreated {
		t.Fatalf("status = %d, want %d body=%q", rec.Code, http.StatusCreated, rec.Body.String())
	}

	var payload map[string]any
	if err := json.Unmarshal(rec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("decode payload: %v", err)
	}
	expiresAt, err := time.Parse(time.RFC3339Nano, payload["expires_at"].(string))
	if err != nil {
		// JSON may marshal as RFC3339
		expiresAt, err = time.Parse(time.RFC3339, payload["expires_at"].(string))
		if err != nil {
			t.Fatalf("parse expires_at %v (%T): %v", payload["expires_at"], payload["expires_at"], err)
		}
	}
	delta := expiresAt.Sub(before)
	if delta < 14*time.Minute || delta > 16*time.Minute {
		t.Fatalf("expires delta = %s, want ~15m", delta)
	}
}

func TestCreateScratchTTLQueryMinMaxAndInvalid(t *testing.T) {
	t.Parallel()

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      15 * time.Minute,
		rateLimitEnable: false,
	})

	cases := []struct {
		name       string
		ttl        string
		wantStatus int
		wantDelta  time.Duration
		deltaSlack time.Duration
	}{
		{name: "min", ttl: "1m", wantStatus: http.StatusCreated, wantDelta: time.Minute, deltaSlack: 15 * time.Second},
		{name: "max", ttl: "24h", wantStatus: http.StatusCreated, wantDelta: 24 * time.Hour, deltaSlack: time.Minute},
		{name: "custom", ttl: "2h", wantStatus: http.StatusCreated, wantDelta: 2 * time.Hour, deltaSlack: 30 * time.Second},
		{name: "below-min", ttl: "30s", wantStatus: http.StatusBadRequest},
		{name: "above-max", ttl: "25h", wantStatus: http.StatusBadRequest},
		{name: "invalid", ttl: "not-a-duration", wantStatus: http.StatusBadRequest},
		{name: "zero", ttl: "0s", wantStatus: http.StatusBadRequest},
		{name: "negative", ttl: "-5m", wantStatus: http.StatusBadRequest},
	}

	for _, tc := range cases {
		tc := tc
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			before := time.Now().UTC()
			req := httptest.NewRequest(http.MethodPost, "/api/scratch?ttl="+tc.ttl, bytes.NewBufferString("body-"+tc.name))
			req.Header.Set("Content-Type", "text/plain; charset=utf-8")
			req.RemoteAddr = "127.0.0.1:8200"
			rec := httptest.NewRecorder()
			handler.ServeHTTP(rec, req)
			if rec.Code != tc.wantStatus {
				t.Fatalf("status = %d, want %d body=%q", rec.Code, tc.wantStatus, rec.Body.String())
			}
			if tc.wantStatus != http.StatusCreated {
				if !strings.Contains(rec.Body.String(), "ttl") {
					t.Fatalf("expected ttl error message, got %q", rec.Body.String())
				}
				return
			}
			var payload map[string]any
			if err := json.Unmarshal(rec.Body.Bytes(), &payload); err != nil {
				t.Fatalf("decode payload: %v", err)
			}
			expiresRaw, _ := payload["expires_at"].(string)
			expiresAt, err := time.Parse(time.RFC3339Nano, expiresRaw)
			if err != nil {
				expiresAt, err = time.Parse(time.RFC3339, expiresRaw)
				if err != nil {
					t.Fatalf("parse expires_at %q: %v", expiresRaw, err)
				}
			}
			delta := expiresAt.Sub(before)
			if delta < tc.wantDelta-tc.deltaSlack || delta > tc.wantDelta+tc.deltaSlack {
				t.Fatalf("expires delta = %s, want ~%s", delta, tc.wantDelta)
			}
		})
	}
}

func TestCreateScratchTTLMultipartFormField(t *testing.T) {
	t.Parallel()

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      15 * time.Minute,
		rateLimitEnable: false,
	})

	var body bytes.Buffer
	writer := multipart.NewWriter(&body)
	file, err := writer.CreateFormFile("file", "ttl.txt")
	if err != nil {
		t.Fatalf("CreateFormFile: %v", err)
	}
	if _, err := file.Write([]byte("multipart-ttl")); err != nil {
		t.Fatalf("write file: %v", err)
	}
	if err := writer.WriteField("ttl", "5m"); err != nil {
		t.Fatalf("WriteField ttl: %v", err)
	}
	if err := writer.Close(); err != nil {
		t.Fatalf("close writer: %v", err)
	}

	before := time.Now().UTC()
	req := httptest.NewRequest(http.MethodPost, "/api/scratch", &body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.RemoteAddr = "127.0.0.1:8301"
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)
	if rec.Code != http.StatusCreated {
		t.Fatalf("status = %d, want %d body=%q", rec.Code, http.StatusCreated, rec.Body.String())
	}

	var payload map[string]any
	if err := json.Unmarshal(rec.Body.Bytes(), &payload); err != nil {
		t.Fatalf("decode payload: %v", err)
	}
	expiresRaw, _ := payload["expires_at"].(string)
	expiresAt, err := time.Parse(time.RFC3339Nano, expiresRaw)
	if err != nil {
		expiresAt, err = time.Parse(time.RFC3339, expiresRaw)
		if err != nil {
			t.Fatalf("parse expires_at %q: %v", expiresRaw, err)
		}
	}
	delta := expiresAt.Sub(before)
	if delta < 4*time.Minute || delta > 6*time.Minute {
		t.Fatalf("expires delta = %s, want ~5m", delta)
	}
}

func TestCreateScratchTTLMultipartInvalid(t *testing.T) {
	t.Parallel()

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  1024,
		defaultTTL:      15 * time.Minute,
		rateLimitEnable: false,
	})

	var body bytes.Buffer
	writer := multipart.NewWriter(&body)
	file, _ := writer.CreateFormFile("file", "bad-ttl.txt")
	_, _ = file.Write([]byte("x"))
	_ = writer.WriteField("ttl", "forever")
	_ = writer.Close()

	req := httptest.NewRequest(http.MethodPost, "/api/scratch", &body)
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.RemoteAddr = "127.0.0.1:8302"
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)
	if rec.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want %d body=%q", rec.Code, http.StatusBadRequest, rec.Body.String())
	}
}

func TestGetUIConfigExposesMaxTTL(t *testing.T) {
	t.Parallel()

	handler := newTestHandler(t, testServerOptions{
		maxUploadBytes:  2048,
		defaultTTL:      15 * time.Minute,
		rateLimitEnable: false,
	})

	// DefaultTTL string is empty in test helper; set via direct server call already covered.
	// Hit routed /api/config and ensure max_ttl is present.
	req := httptest.NewRequest(http.MethodGet, "/api/config", nil)
	req.RemoteAddr = "127.0.0.1:8401"
	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
	}
	body := rec.Body.String()
	if !strings.Contains(body, `"max_ttl"`) {
		t.Fatalf("expected max_ttl in body: %q", body)
	}
}