package ingest

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"sync/atomic"
	"testing"
	"time"
)

func TestFetchExportLimitedRetries429ThenSucceeds(t *testing.T) {
	var attempts atomic.Int32

	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		n := attempts.Add(1)

		if n <= 2 {
			w.Header().Set("Retry-After", "0")
			http.Error(w, "rate limited", http.StatusTooManyRequests)

			return
		}

		_, _ = fmt.Fprintln(w, `{"seq":1,"did":"did:plc:alice","cid":"cid1","operation":{"x":1}}`)
	}))

	defer ts.Close()

	client := NewClient(ts.URL, ClientOptions{
		MaxAttempts: 5,
		BaseDelay:   time.Millisecond,
		MaxDelay:    2 * time.Millisecond,
	})
	records, err := client.FetchExportLimited(context.Background(), 0, 0)

	if err != nil {
		t.Fatalf("fetch export: %v", err)
	}

	if len(records) != 1 {
		t.Fatalf("record count mismatch: got %d want 1", len(records))
	}

	if got := attempts.Load(); got != 3 {
		t.Fatalf("attempt count mismatch: got %d want 3", got)
	}
}

func TestFetchExportLimitedDoesNotRetry400(t *testing.T) {
	var attempts atomic.Int32

	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts.Add(1)
		http.Error(w, "bad request", http.StatusBadRequest)
	}))

	defer ts.Close()

	client := NewClient(ts.URL, ClientOptions{
		MaxAttempts: 5,
		BaseDelay:   time.Millisecond,
		MaxDelay:    2 * time.Millisecond,
	})
	_, err := client.FetchExportLimited(context.Background(), 0, 0)

	if err == nil {
		t.Fatalf("expected error for 400 response")
	}

	if got := attempts.Load(); got != 1 {
		t.Fatalf("unexpected retries on 400: got attempts=%d want 1", got)
	}
}

func TestFetchDIDLogRetries429ThenSucceeds(t *testing.T) {
	const did = "did:plc:retry429"
	var attempts atomic.Int32

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/"+did+"/log" {
			http.NotFound(w, r)

			return
		}

		n := attempts.Add(1)
		if n <= 2 {
			w.Header().Set("Retry-After", "0")
			http.Error(w, "rate limited", http.StatusTooManyRequests)

			return
		}

		_ = json.NewEncoder(w).Encode([]map[string]any{
			{
				"did":       did,
				"cid":       "bafy-retry",
				"createdAt": "2026-02-27T00:00:00Z",
				"operation": json.RawMessage(`{"did":"did:plc:retry429","sig":"x","sigPayload":"e30","rotationKeys":["did:key:z"],"verificationMethods":{"atproto":"did:key:z"}}`),
			},
		})
	}))

	defer srv.Close()

	client := NewClient(srv.URL, ClientOptions{
		MaxAttempts: 5,
		BaseDelay:   time.Millisecond,
		MaxDelay:    2 * time.Millisecond,
	})
	records, err := client.FetchDIDLog(context.Background(), did)

	if err != nil {
		t.Fatalf("fetch did log: %v", err)
	}

	if len(records) != 1 {
		t.Fatalf("record count mismatch: got %d want 1", len(records))
	}

	if got := attempts.Load(); got != 3 {
		t.Fatalf("attempt count mismatch: got %d want 3", got)
	}
}

func TestFetchDIDLogAuditFallbackRetries429ThenSucceeds(t *testing.T) {
	const did = "did:plc:auditretry"
	var auditAttempts atomic.Int32

	op := json.RawMessage(`{"did":"did:plc:auditretry","sig":"x","sigPayload":"e30","rotationKeys":["did:key:z"],"verificationMethods":{"atproto":"did:key:z"}}`)

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.URL.Path {
		case "/" + did + "/log":
			_ = json.NewEncoder(w).Encode([]json.RawMessage{op})
		case "/" + did + "/log/audit":
			n := auditAttempts.Add(1)
			if n == 1 {
				w.Header().Set("Retry-After", "0")
				http.Error(w, "rate limited", http.StatusTooManyRequests)

				return
			}

			_ = json.NewEncoder(w).Encode([]map[string]any{{
				"did":       did,
				"operation": op,
				"cid":       "bafy-audit",
				"createdAt": "2026-02-27T00:00:00Z",
			}})
		default:
			http.NotFound(w, r)
		}
	}))

	defer srv.Close()

	client := NewClient(srv.URL, ClientOptions{
		MaxAttempts: 5,
		BaseDelay:   time.Millisecond,
		MaxDelay:    2 * time.Millisecond,
	})
	records, err := client.FetchDIDLog(context.Background(), did)

	if err != nil {
		t.Fatalf("fetch did log: %v", err)
	}

	if len(records) != 1 {
		t.Fatalf("record count mismatch: got %d want 1", len(records))
	}

	if records[0].CID != "bafy-audit" {
		t.Fatalf("cid mismatch: got %q want %q", records[0].CID, "bafy-audit")
	}

	if got := auditAttempts.Load(); got != 2 {
		t.Fatalf("audit attempt count mismatch: got %d want 2", got)
	}
}