package gitea

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

func TestGetPullRequest(t *testing.T) {
	pr := PullRequest{
		Title: "Add feature X",
		Body:  "This adds feature X.",
	}
	pr.Head.Sha = "abc123"

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/repos/owner/repo/pulls/1" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		if r.Header.Get("Authorization") != "token test-token" {
			t.Errorf("unexpected auth header: %s", r.Header.Get("Authorization"))
		}
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(pr)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	got, err := client.GetPullRequest(context.Background(), "owner", "repo", 1)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if got.Title != "Add feature X" {
		t.Errorf("expected title %q, got %q", "Add feature X", got.Title)
	}
	if got.Body != "This adds feature X." {
		t.Errorf("expected body %q, got %q", "This adds feature X.", got.Body)
	}
	if got.Head.Sha != "abc123" {
		t.Errorf("expected sha %q, got %q", "abc123", got.Head.Sha)
	}
}

func TestGetPullRequestDiff(t *testing.T) {
	expectedDiff := "diff --git a/file.go b/file.go\n--- a/file.go\n+++ b/file.go\n@@ -1 +1 @@\n-old\n+new\n"

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/repos/owner/repo/pulls/5.diff" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		w.Write([]byte(expectedDiff))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	got, err := client.GetPullRequestDiff(context.Background(), "owner", "repo", 5)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if got != expectedDiff {
		t.Errorf("expected diff %q, got %q", expectedDiff, got)
	}
}

func TestGetCommitStatuses(t *testing.T) {
	statuses := []CommitStatus{
		{Status: "success", Context: "ci/test", Description: "All tests passed"},
		{Status: "failure", Context: "ci/lint", Description: "Lint failed"},
	}

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/repos/owner/repo/commits/abc123/statuses" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(statuses)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	got, err := client.GetCommitStatuses(context.Background(), "owner", "repo", "abc123")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(got) != 2 {
		t.Fatalf("expected 2 statuses, got %d", len(got))
	}
	if got[0].Status != "success" {
		t.Errorf("expected first status %q, got %q", "success", got[0].Status)
	}
	if got[1].Status != "failure" {
		t.Errorf("expected second status %q, got %q", "failure", got[1].Status)
	}
}

func TestPostReview(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != "POST" {
			t.Errorf("expected POST, got %s", r.Method)
		}
		if r.URL.Path != "/api/v1/repos/owner/repo/pulls/3/reviews" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		if r.Header.Get("Content-Type") != "application/json" {
			t.Errorf("unexpected content type: %s", r.Header.Get("Content-Type"))
		}

		var payload struct {
			Body  string `json:"body"`
			Event string `json:"event"`
		}
		if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
			t.Fatalf("failed to decode payload: %v", err)
		}
		if payload.Body != "LGTM" {
			t.Errorf("expected body %q, got %q", "LGTM", payload.Body)
		}
		if payload.Event != "APPROVED" {
			t.Errorf("expected event %q, got %q", "APPROVED", payload.Event)
		}

		w.WriteHeader(http.StatusOK)
		w.Write([]byte(`{"id":100,"user":{"login":"review-bot"},"state":"APPROVED","stale":false}`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	review, err := client.PostReview(context.Background(), "owner", "repo", 3, "APPROVED", "LGTM", nil)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if review.ID != 100 {
		t.Errorf("expected review ID 100, got %d", review.ID)
	}
	if review.User.Login != "review-bot" {
		t.Errorf("expected user login %q, got %q", "review-bot", review.User.Login)
	}
}

func TestGetPullRequest_Non200(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusNotFound)
		w.Write([]byte(`{"message":"not found"}`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	_, err := client.GetPullRequest(context.Background(), "owner", "repo", 999)
	if err == nil {
		t.Fatal("expected error for 404, got nil")
	}
}

func TestGetPullRequest_BadJSON(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte(`not json`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	_, err := client.GetPullRequest(context.Background(), "owner", "repo", 1)
	if err == nil {
		t.Fatal("expected error for bad JSON, got nil")
	}
}

func TestPostReview_Non200(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusForbidden)
		w.Write([]byte(`{"message":"forbidden"}`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	_, err := client.PostReview(context.Background(), "owner", "repo", 1, "APPROVED", "test", nil)
	if err == nil {
		t.Fatal("expected error for 403, got nil")
	}
}

func TestGetFileContent(t *testing.T) {
	expected := "# Conventions\n- Be nice\n"

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/repos/owner/repo/raw/CONVENTIONS.md" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		w.Write([]byte(expected))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	got, err := client.GetFileContent(context.Background(), "owner", "repo", "CONVENTIONS.md")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if got != expected {
		t.Errorf("expected %q, got %q", expected, got)
	}
}

func TestGetPullRequestFiles(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/repos/owner/repo/pulls/1/files" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`[{"filename":"main.go","status":"modified"},{"filename":"old.go","status":"removed"}]`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	files, err := client.GetPullRequestFiles(context.Background(), "owner", "repo", 1)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(files) != 2 {
		t.Fatalf("expected 2 files, got %d", len(files))
	}
	if files[0].Filename != "main.go" || files[0].Status != "modified" {
		t.Errorf("unexpected first file: %+v", files[0])
	}
}

func TestGetFileContentRef(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/repos/owner/repo/raw/main.go" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		if r.URL.Query().Get("ref") != "feature-branch" {
			t.Errorf("unexpected ref: %s", r.URL.Query().Get("ref"))
		}
		w.Write([]byte("package main\n"))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	content, err := client.GetFileContentRef(context.Background(), "owner", "repo", "main.go", "feature-branch")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if content != "package main\n" {
		t.Errorf("unexpected content: %q", content)
	}
}

func TestListContents(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/repos/owner/repo/contents/docs" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		w.Header().Set("Content-Type", "application/json")
		fmt.Fprintf(w, `[{"name":"guide.md","path":"docs/guide.md","type":"file"},{"name":"sub","path":"docs/sub","type":"dir"}]`)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	entries, err := client.ListContents(context.Background(), "owner", "repo", "docs")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(entries) != 2 {
		t.Fatalf("expected 2 entries, got %d", len(entries))
	}
	if entries[0].Type != "file" || entries[0].Path != "docs/guide.md" {
		t.Errorf("unexpected first entry: %+v", entries[0])
	}
	if entries[1].Type != "dir" {
		t.Errorf("expected dir type, got %s", entries[1].Type)
	}
}

func TestListContents_DotPath(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// "." should be normalized to empty path, which hits the root contents endpoint
		if r.URL.Path != "/api/v1/repos/owner/repo/contents" {
			t.Errorf("expected root contents path, got: %s", r.URL.Path)
		}
		w.Header().Set("Content-Type", "application/json")
		fmt.Fprintf(w, `[{"name":"README.md","path":"README.md","type":"file"}]`)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	entries, err := client.ListContents(context.Background(), "owner", "repo", ".")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(entries) != 1 {
		t.Fatalf("expected 1 entry, got %d", len(entries))
	}
	if entries[0].Name != "README.md" {
		t.Errorf("expected README.md, got %s", entries[0].Name)
	}
}

func TestListContents_FilePath(t *testing.T) {
	// Gitea returns a single object (not an array) when path is a file
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/repos/owner/repo/contents/README.md" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		w.Header().Set("Content-Type", "application/json")
		// Single object, not an array
		fmt.Fprintf(w, `{"name":"README.md","path":"README.md","type":"file"}`)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	entries, err := client.ListContents(context.Background(), "owner", "repo", "README.md")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(entries) != 1 {
		t.Fatalf("expected 1 entry, got %d", len(entries))
	}
	if entries[0].Name != "README.md" {
		t.Errorf("expected README.md, got %s", entries[0].Name)
	}
	if entries[0].Type != "file" {
		t.Errorf("expected type file, got %s", entries[0].Type)
	}
}

func TestGetAllFilesInPath_File(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path == "/api/v1/repos/owner/repo/contents/README.md" {
			// Gitea returns a single object (not array) when path is a file
			w.Header().Set("Content-Type", "application/json")
			fmt.Fprintf(w, `{"name":"README.md","path":"README.md","type":"file"}`)
			return
		}
		if r.URL.Path == "/api/v1/repos/owner/repo/raw/README.md" {
			fmt.Fprintf(w, "# Hello")
			return
		}
		http.NotFound(w, r)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	files, err := client.GetAllFilesInPath(context.Background(), "owner", "repo", "README.md")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(files) != 1 {
		t.Fatalf("expected 1 file, got %d", len(files))
	}
	if files["README.md"] != "# Hello" {
		t.Errorf("unexpected content: %q", files["README.md"])
	}
}

func TestEscapePath(t *testing.T) {
	tests := []struct {
		name  string
		input string
		want  string
	}{
		{"simple", "src/main.go", "src/main.go"},
		{"spaces", "my dir/my file.go", "my%20dir/my%20file.go"},
		{"special chars", "path/file#1.txt", "path/file%231.txt"},
		{"empty", "", ""},
		{"single segment", "README.md", "README.md"},
		{"nested deep", "a/b/c/d.md", "a/b/c/d.md"},
		{"already encoded", "path/file%20name.go", "path/file%2520name.go"},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := escapePath(tt.input)
			if got != tt.want {
				t.Errorf("escapePath(%q) = %q, want %q", tt.input, got, tt.want)
			}
		})
	}
}

func TestListReviews(t *testing.T) {
	pageCount := 0
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/repos/owner/repo/pulls/5/reviews" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		if r.URL.Query().Get("limit") != "50" {
			t.Errorf("expected limit=50, got %s", r.URL.Query().Get("limit"))
		}
		pageCount++
		w.Header().Set("Content-Type", "application/json")
		// Return 2 results (less than page size) to signal end
		w.Write([]byte(`[{"id":10,"user":{"login":"bot-a"},"state":"APPROVED","stale":false},{"id":11,"user":{"login":"bot-b"},"state":"REQUEST_CHANGES","stale":true}]`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	reviews, err := client.ListReviews(context.Background(), "owner", "repo", 5)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(reviews) != 2 {
		t.Fatalf("expected 2 reviews, got %d", len(reviews))
	}
	if reviews[0].User.Login != "bot-a" {
		t.Errorf("expected bot-a, got %s", reviews[0].User.Login)
	}
	if pageCount != 1 {
		t.Errorf("expected 1 page fetch (results < page size), got %d", pageCount)
	}
}

func TestListReviews_Pagination(t *testing.T) {
	pageCount := 0
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		pageCount++
		page := r.URL.Query().Get("page")
		w.Header().Set("Content-Type", "application/json")
		if page == "1" {
			// Return exactly 50 items to trigger next page fetch
			items := "["
			for i := 0; i < 50; i++ {
				if i > 0 {
					items += ","
				}
				items += fmt.Sprintf(`{"id":%d,"user":{"login":"bot"},"state":"APPROVED","stale":false}`, i+1)
			}
			items += "]"
			w.Write([]byte(items))
		} else {
			// Page 2: return fewer than 50 to signal end
			w.Write([]byte(`[{"id":51,"user":{"login":"bot"},"state":"APPROVED","stale":false}]`))
		}
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	reviews, err := client.ListReviews(context.Background(), "owner", "repo", 5)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(reviews) != 51 {
		t.Fatalf("expected 51 reviews across 2 pages, got %d", len(reviews))
	}
	if pageCount != 2 {
		t.Errorf("expected 2 page fetches, got %d", pageCount)
	}
}

func TestDeleteReview(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/repos/owner/repo/pulls/5/reviews/10" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		if r.Method != "DELETE" {
			t.Errorf("expected DELETE, got %s", r.Method)
		}
		w.WriteHeader(http.StatusNoContent)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	err := client.DeleteReview(context.Background(), "owner", "repo", 5, 10)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
}

func TestDeleteReview_Forbidden(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusForbidden)
		w.Write([]byte(`{"message":"forbidden"}`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	err := client.DeleteReview(context.Background(), "owner", "repo", 5, 10)
	if err == nil {
		t.Fatal("expected error for 403, got nil")
	}
}

func TestEditComment(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPatch {
			t.Errorf("expected PATCH, got %s", r.Method)
		}
		if r.URL.Path != "/api/v1/repos/owner/repo/issues/comments/42" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}

		var payload struct {
			Body string `json:"body"`
		}
		json.NewDecoder(r.Body).Decode(&payload)
		if payload.Body != "updated body" {
			t.Errorf("unexpected body: %s", payload.Body)
		}

		w.WriteHeader(http.StatusOK)
		w.Write([]byte(`{"id": 42, "body": "updated body"}`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	err := client.EditComment(context.Background(), "owner", "repo", 42, "updated body")
	if err != nil {
		t.Fatalf("EditComment() error = %v", err)
	}
}

func TestEditComment_Forbidden(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusForbidden)
		w.Write([]byte(`{"message": "not allowed"}`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	err := client.EditComment(context.Background(), "owner", "repo", 42, "new body")
	if err == nil {
		t.Fatal("expected error for 403 response")
	}
}

func TestGetTimelineReviewCommentID(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/repos/owner/repo/issues/5/timeline" {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		w.Write([]byte(`[
			{"id": 100, "type": "comment", "body": "random"},
			{"id": 200, "type": "review", "body": "other review <!-- review-bot:gpt -->"},
			{"id": 300, "type": "review", "body": "our review <!-- review-bot:sonnet -->"}
		]`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	id, err := client.GetTimelineReviewCommentID(context.Background(), "owner", "repo", 5, "<!-- review-bot:sonnet -->")
	if err != nil {
		t.Fatalf("GetTimelineReviewCommentID() error = %v", err)
	}
	if id != 300 {
		t.Errorf("got id=%d, want 300", id)
	}
}

func TestGetTimelineReviewCommentID_NotFound(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte(`[{"id": 100, "type": "review", "body": "no match"}]`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	_, err := client.GetTimelineReviewCommentID(context.Background(), "owner", "repo", 5, "<!-- review-bot:sonnet -->")
	if err == nil {
		t.Fatal("expected error when sentinel not found")
	}
}

func TestGetAllFilesInPath_404FallsBackToFile(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.URL.Path {
		case "/api/v1/repos/owner/repo/contents/README.md":
			// Contents API returns 404 for files (not a directory)
			w.WriteHeader(http.StatusNotFound)
			w.Write([]byte(`{"message":"not found"}`))
		case "/api/v1/repos/owner/repo/raw/README.md":
			w.Write([]byte("# Hello\n"))
		default:
			w.WriteHeader(http.StatusNotFound)
			w.Write([]byte(`{"message":"not found"}`))
		}
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	files, err := client.GetAllFilesInPath(context.Background(), "owner", "repo", "README.md")
	if err != nil {
		t.Fatalf("expected fallback to file on 404, got error: %v", err)
	}
	if len(files) != 1 {
		t.Fatalf("expected 1 file, got %d", len(files))
	}
	if files["README.md"] != "# Hello\n" {
		t.Errorf("unexpected content: %q", files["README.md"])
	}
}

func TestGetAllFilesInPath_500Propagates(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Simulate a server error from ListContents
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte(`{"message":"internal server error"}`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	_, err := client.GetAllFilesInPath(context.Background(), "owner", "repo", "somepath")
	if err == nil {
		t.Fatal("expected error to propagate for 500, got nil")
	}
	// Should NOT fall back to file fetch — error should propagate
	var apiErr *APIError
	if !errors.As(err, &apiErr) {
		t.Fatalf("expected APIError in chain, got: %v", err)
	}
	if apiErr.StatusCode != http.StatusInternalServerError {
		t.Errorf("expected status 500, got %d", apiErr.StatusCode)
	}
}

func TestGetAllFilesInPath_403Propagates(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusForbidden)
		w.Write([]byte(`{"message":"token has insufficient scope"}`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	_, err := client.GetAllFilesInPath(context.Background(), "owner", "repo", "private/stuff")
	if err == nil {
		t.Fatal("expected error to propagate for 403, got nil")
	}
	var apiErr *APIError
	if !errors.As(err, &apiErr) {
		t.Fatalf("expected APIError in chain, got: %v", err)
	}
	if apiErr.StatusCode != http.StatusForbidden {
		t.Errorf("expected status 403, got %d", apiErr.StatusCode)
	}
}

func TestIsNotFound(t *testing.T) {
	tests := []struct {
		name string
		err  error
		want bool
	}{
		{"nil error", nil, false},
		{"non-API error", fmt.Errorf("network timeout"), false},
		{"404 APIError", &APIError{StatusCode: 404, Body: "not found"}, true},
		{"500 APIError", &APIError{StatusCode: 500, Body: "server error"}, false},
		{"wrapped 404", fmt.Errorf("list contents: %w", &APIError{StatusCode: 404, Body: "not found"}), true},
		{"wrapped 500", fmt.Errorf("list contents: %w", &APIError{StatusCode: 500, Body: "err"}), false},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := IsNotFound(tt.err)
			if got != tt.want {
				t.Errorf("IsNotFound(%v) = %v, want %v", tt.err, got, tt.want)
			}
		})
	}
}

func TestGetAuthenticatedUser(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/v1/user" {
			t.Errorf("unexpected path: %s", r.URL.Path)
			http.NotFound(w, r)
			return
		}
		if r.Header.Get("Authorization") != "token test-token" {
			t.Error("missing or wrong auth header")
		}
		w.Header().Set("Content-Type", "application/json")
		fmt.Fprint(w, `{"login":"my-bot","id":42}`)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	login, err := client.GetAuthenticatedUser(context.Background())
	if err != nil {
		t.Fatalf("GetAuthenticatedUser() error = %v", err)
	}
	if login != "my-bot" {
		t.Errorf("login = %q, want %q", login, "my-bot")
	}
}

func TestRequestReviewer(t *testing.T) {
	var gotBody []byte
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost {
			t.Errorf("expected POST, got %s", r.Method)
		}
		expected := "/api/v1/repos/owner/repo/pulls/7/requested_reviewers"
		if r.URL.Path != expected {
			t.Errorf("path = %q, want %q", r.URL.Path, expected)
		}
		gotBody, _ = io.ReadAll(r.Body)
		w.WriteHeader(http.StatusCreated)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	err := client.RequestReviewer(context.Background(), "owner", "repo", 7, "bot-user")
	if err != nil {
		t.Fatalf("RequestReviewer() error = %v", err)
	}
	if !strings.Contains(string(gotBody), `"bot-user"`) {
		t.Errorf("body = %s, want to contain bot-user", gotBody)
	}
}

func TestRequestReviewer_204(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusNoContent)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	err := client.RequestReviewer(context.Background(), "owner", "repo", 1, "user")
	if err != nil {
		t.Fatalf("RequestReviewer() should accept 204, got error = %v", err)
	}
}

func TestRequestReviewer_Error(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusForbidden)
		fmt.Fprint(w, "no permission")
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	err := client.RequestReviewer(context.Background(), "owner", "repo", 1, "user")
	if err == nil {
		t.Fatal("expected error for 403 response")
	}
	if !strings.Contains(err.Error(), "403") {
		t.Errorf("error should mention status code: %v", err)
	}
}

func TestListReviewComments(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if !strings.Contains(r.URL.Path, "/pulls/1/reviews/42/comments") {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		w.Header().Set("Content-Type", "application/json")
		fmt.Fprint(w, `[{"id":100,"path":"main.go","new_position":5,"body":"finding"},{"id":101,"path":"lib.go","new_position":10,"body":"another"}]`)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	comments, err := client.ListReviewComments(context.Background(), "owner", "repo", 1, 42)
	if err != nil {
		t.Fatalf("ListReviewComments() error = %v", err)
	}
	if len(comments) != 2 {
		t.Fatalf("got %d comments, want 2", len(comments))
	}
	if comments[0].ID != 100 {
		t.Errorf("comments[0].ID = %d, want 100", comments[0].ID)
	}
	if comments[1].Path != "lib.go" {
		t.Errorf("comments[1].Path = %q, want %q", comments[1].Path, "lib.go")
	}
}

func TestResolveComment(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost {
			t.Errorf("expected POST, got %s", r.Method)
		}
		if !strings.Contains(r.URL.Path, "/pulls/comments/99/resolve") {
			t.Errorf("unexpected path: %s", r.URL.Path)
		}
		w.WriteHeader(http.StatusOK)
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	err := client.ResolveComment(context.Background(), "owner", "repo", 99)
	if err != nil {
		t.Fatalf("ResolveComment() error = %v", err)
	}
}

func TestResolveComment_Error(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusNotFound)
		fmt.Fprint(w, "not found")
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	err := client.ResolveComment(context.Background(), "owner", "repo", 99)
	if err == nil {
		t.Fatal("expected error for 404 response")
	}
}

func TestIsServerError(t *testing.T) {
	tests := []struct {
		name string
		err  error
		want bool
	}{
		{"nil error", nil, false},
		{"non-API error", fmt.Errorf("network timeout"), false},
		{"404 APIError", &APIError{StatusCode: 404, Body: "not found"}, false},
		{"500 APIError", &APIError{StatusCode: 500, Body: "server error"}, true},
		{"502 APIError", &APIError{StatusCode: 502, Body: "bad gateway"}, true},
		{"503 APIError", &APIError{StatusCode: 503, Body: "unavailable"}, true},
		{"599 APIError", &APIError{StatusCode: 599, Body: "edge case"}, true},
		{"600 not server error", &APIError{StatusCode: 600, Body: "edge"}, false},
		{"400 not server error", &APIError{StatusCode: 400, Body: "bad request"}, false},
		{"wrapped 500", fmt.Errorf("fetch: %w", &APIError{StatusCode: 500, Body: "err"}), true},
		{"wrapped 404", fmt.Errorf("fetch: %w", &APIError{StatusCode: 404, Body: "err"}), false},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := IsServerError(tt.err)
			if got != tt.want {
				t.Errorf("IsServerError(%v) = %v, want %v", tt.err, got, tt.want)
			}
		})
	}
}

func TestDoGet_RetriesOn500(t *testing.T) {
	attempts := 0
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		if attempts < 3 {
			w.WriteHeader(http.StatusInternalServerError)
			w.Write([]byte(`{"message":"transient error"}`))
			return
		}
		w.WriteHeader(http.StatusOK)
		w.Write([]byte(`{"data":"success"}`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	// Use short backoff for fast tests
	client.RetryBackoff = []time.Duration{1 * time.Millisecond, 1 * time.Millisecond}

	body, err := client.doGet(context.Background(), server.URL+"/test")
	if err != nil {
		t.Fatalf("expected success after retry, got error: %v", err)
	}
	if string(body) != `{"data":"success"}` {
		t.Errorf("body = %q, want %q", string(body), `{"data":"success"}`)
	}
	if attempts != 3 {
		t.Errorf("attempts = %d, want 3", attempts)
	}
}

func TestDoGet_FailsAfterMaxRetries(t *testing.T) {
	attempts := 0
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte(`{"message":"persistent error"}`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	// Use short backoff for fast tests
	client.RetryBackoff = []time.Duration{1 * time.Millisecond, 1 * time.Millisecond}

	_, err := client.doGet(context.Background(), server.URL+"/test")
	if err == nil {
		t.Fatal("expected error after max retries")
	}
	var apiErr *APIError
	if !errors.As(err, &apiErr) {
		t.Fatalf("expected APIError, got: %v", err)
	}
	if apiErr.StatusCode != http.StatusInternalServerError {
		t.Errorf("status = %d, want 500", apiErr.StatusCode)
	}
	if attempts != 3 {
		t.Errorf("attempts = %d, want 3 (max retries)", attempts)
	}
}

func TestDoGet_NoRetryOn4xx(t *testing.T) {
	attempts := 0
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		w.WriteHeader(http.StatusForbidden)
		w.Write([]byte(`{"message":"forbidden"}`))
	}))
	defer server.Close()

	client := NewClient(server.URL, "test-token")
	_, err := client.doGet(context.Background(), server.URL+"/test")
	if err == nil {
		t.Fatal("expected error for 403")
	}
	var apiErr *APIError
	if !errors.As(err, &apiErr) {
		t.Fatalf("expected APIError, got: %v", err)
	}
	if apiErr.StatusCode != http.StatusForbidden {
		t.Errorf("status = %d, want 403", apiErr.StatusCode)
	}
	if attempts != 1 {
		t.Errorf("attempts = %d, want 1 (no retry on 4xx)", attempts)
	}
}

func TestDoGet_RespectsContextCancellation(t *testing.T) {
	attempts := 0
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte(`{"message":"error"}`))
	}))
	defer server.Close()

	ctx, cancel := context.WithCancel(context.Background())

	client := NewClient(server.URL, "test-token")
	// Use longer backoff to give us time to cancel during the wait
	client.RetryBackoff = []time.Duration{100 * time.Millisecond, 100 * time.Millisecond}

	// Cancel after first attempt returns and retry begins
	go func() {
		time.Sleep(20 * time.Millisecond)
		cancel()
	}()

	_, err := client.doGet(ctx, server.URL+"/test")
	if err == nil {
		t.Fatal("expected error on context cancellation")
	}
	// Should have made 1 attempt, then context cancelled during backoff
	if attempts != 1 {
		t.Errorf("attempts = %d, expected 1 before context cancel during backoff", attempts)
	}
}


// mockTransport is a test helper that returns errors for the first N calls,
// then delegates to a real server.
type mockTransport struct {
	failCount    int32 // number of failures remaining (atomic)
	failErr      error // error to return on failure
	realServer   *httptest.Server
	attemptsMade atomic.Int32 // tracks total attempts
}

func (m *mockTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	m.attemptsMade.Add(1)
	remaining := atomic.AddInt32(&m.failCount, -1)
	if remaining >= 0 {
		// Still have failures to return
		return nil, m.failErr
	}
	// Redirect to real server
	req.URL.Host = m.realServer.Listener.Addr().String()
	req.URL.Scheme = "http"
	return http.DefaultTransport.RoundTrip(req)
}

func TestDoGet_RetriesOnTemporaryNetError(t *testing.T) {
	// Real server that will handle successful requests
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte(`{"status":"ok"}`))
	}))
	defer server.Close()

	// Mock transport: fail twice with ECONNREFUSED, then succeed
	mt := &mockTransport{
		failCount:  2,
		failErr:    &net.OpError{Op: "dial", Net: "tcp", Err: syscall.ECONNREFUSED},
		realServer: server,
	}

	client := NewClient("http://fake-host/", "test-token")
	client.SetHTTPClient(&http.Client{Transport: mt})
	client.RetryBackoff = []time.Duration{1 * time.Millisecond, 1 * time.Millisecond}

	body, err := client.doGet(context.Background(), "http://fake-host/test")
	if err != nil {
		t.Fatalf("expected success after retries, got error: %v", err)
	}
	if string(body) != `{"status":"ok"}` {
		t.Errorf("body = %q, want %q", string(body), `{"status":"ok"}`)
	}

	// Should have made exactly 3 attempts: 2 failures + 1 success
	if got := mt.attemptsMade.Load(); got != 3 {
		t.Errorf("attempts = %d, want 3 (2 failures + 1 success)", got)
	}
}

func TestIsTemporaryNetError(t *testing.T) {
	tests := []struct {
		name string
		err  error
		want bool
	}{
		{"nil error", nil, false},
		{"plain error", fmt.Errorf("some error"), false},
		// OpError with retriable syscall errors
		{"OpError ECONNREFUSED", &net.OpError{Op: "dial", Err: syscall.ECONNREFUSED}, true},
		{"OpError ECONNRESET", &net.OpError{Op: "read", Err: syscall.ECONNRESET}, true},
		{"OpError ENETUNREACH", &net.OpError{Op: "dial", Err: syscall.ENETUNREACH}, true},
		{"OpError EHOSTUNREACH", &net.OpError{Op: "dial", Err: syscall.EHOSTUNREACH}, true},
		{"OpError ETIMEDOUT", &net.OpError{Op: "dial", Err: syscall.ETIMEDOUT}, true},
		// OpError with permanent syscall errors — should NOT retry
		{"OpError EACCES", &net.OpError{Op: "dial", Err: syscall.EACCES}, false},
		{"OpError EPERM", &net.OpError{Op: "dial", Err: syscall.EPERM}, false},
		// OpError with unknown inner error — conservative retry
		{"OpError unknown inner", &net.OpError{Op: "dial", Err: fmt.Errorf("unknown")}, true},
		// DNS errors
		{"DNS timeout", &net.DNSError{IsTimeout: true}, true},
		{"DNS no such host", &net.DNSError{IsTimeout: false, Name: "bad.host"}, false},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := isTemporaryNetError(tt.err)
			if got != tt.want {
				t.Errorf("isTemporaryNetError(%v) = %v, want %v", tt.err, got, tt.want)
			}
		})
	}
}

func TestIsRetriableSyscallError(t *testing.T) {
	tests := []struct {
		name string
		err  error
		want bool
	}{
		{"nil", nil, false},
		{"ECONNREFUSED", syscall.ECONNREFUSED, true},
		{"ECONNRESET", syscall.ECONNRESET, true},
		{"ENETUNREACH", syscall.ENETUNREACH, true},
		{"EHOSTUNREACH", syscall.EHOSTUNREACH, true},
		{"ETIMEDOUT", syscall.ETIMEDOUT, true},
		{"EACCES (permanent)", syscall.EACCES, false},
		{"EPERM (permanent)", syscall.EPERM, false},
		{"ENOENT (permanent)", syscall.ENOENT, false},
		{"unknown error", fmt.Errorf("something"), true}, // conservative retry
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := isRetriableSyscallError(tt.err)
			if got != tt.want {
				t.Errorf("isRetriableSyscallError(%v) = %v, want %v", tt.err, got, tt.want)
			}
		})
	}
}

func TestRedactURL(t *testing.T) {
	tests := []struct {
		name  string
		input string
		want  string
	}{
		{
			name:  "no query params",
			input: "https://gitea.example.com/api/v1/repos/owner/repo/pulls/1",
			want:  "https://gitea.example.com/api/v1/repos/owner/repo/pulls/1",
		},
		{
			name:  "with query params - redacts",
			input: "https://gitea.example.com/api/v1/repos/owner/repo/raw/file?ref=main",
			want:  "https://gitea.example.com/api/v1/repos/owner/repo/raw/file?[redacted]",
		},
		{
			name:  "multiple query params",
			input: "https://example.com/path?token=secret&page=1",
			want:  "https://example.com/path?[redacted]",
		},
		{
			name:  "invalid URL",
			input: "://invalid",
			want:  "[invalid URL]",
		},
		{
			name:  "empty string",
			input: "",
			want:  "",
		},
		{
			name:  "with userinfo - redacts credentials",
			input: "https://admin:secret@gitea.example.com/api/v1/repos",
			want:  "https://REDACTED@gitea.example.com/api/v1/repos",
		},
		{
			name:  "with userinfo and query params",
			input: "https://user:pass@example.com/path?token=abc",
			want:  "https://REDACTED@example.com/path?[redacted]",
		},
		{
			name:  "username only - no password",
			input: "https://user@example.com/path",
			want:  "https://REDACTED@example.com/path",
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := redactURL(tt.input)
			if got != tt.want {
				t.Errorf("redactURL(%q) = %q, want %q", tt.input, got, tt.want)
			}
		})
	}
}

func TestSanitizeErrorForLog(t *testing.T) {
	tests := []struct {
		name string
		err  error
		want string
	}{
		{
			name: "nil error",
			err:  nil,
			want: "<nil>",
		},
		{
			name: "APIError omits body",
			err:  &APIError{StatusCode: 500, Body: "internal error: database connection failed"},
			want: "HTTP 500",
		},
		{
			name: "APIError with large body still only shows status",
			err:  &APIError{StatusCode: 502, Body: strings.Repeat("x", 1000)},
			want: "HTTP 502",
		},
		{
			name: "non-API error preserved",
			err:  fmt.Errorf("connection refused"),
			want: "connection refused",
		},
		{
			name: "wrapped APIError",
			err:  fmt.Errorf("request failed: %w", &APIError{StatusCode: 503, Body: "service unavailable"}),
			want: "HTTP 503",
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := sanitizeErrorForLog(tt.err)
			if got != tt.want {
				t.Errorf("sanitizeErrorForLog() = %q, want %q", got, tt.want)
			}
		})
	}
}