package main

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"testing"

	"gcy_hpc_server/internal/model"
	"gcy_hpc_server/internal/testutil/testenv"
)

// fileAPIResp mirrors server.APIResponse for file integration tests.
type fileAPIResp struct {
	Success bool            `json:"success"`
	Data    json.RawMessage `json:"data,omitempty"`
	Error   string          `json:"error,omitempty"`
}

// fileDecode parses an HTTP response body into fileAPIResp.
func fileDecode(t *testing.T, body io.Reader) fileAPIResp {
	t.Helper()
	data, err := io.ReadAll(body)
	if err != nil {
		t.Fatalf("fileDecode: read body: %v", err)
	}
	var r fileAPIResp
	if err := json.Unmarshal(data, &r); err != nil {
		t.Fatalf("fileDecode: unmarshal: %v (body: %s)", err, string(data))
	}
	return r
}

func TestIntegration_File_List(t *testing.T) {
	env := testenv.NewTestEnv(t)

	// Upload a file so the list is non-empty.
	env.UploadTestData("list_test.txt", []byte("hello list"))

	resp := env.DoRequest("GET", "/api/v1/files", nil)
	defer resp.Body.Close()

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

	r := fileDecode(t, resp.Body)
	if !r.Success {
		t.Fatalf("response not success: %s", r.Error)
	}

	var listResp model.ListFilesResponse
	if err := json.Unmarshal(r.Data, &listResp); err != nil {
		t.Fatalf("unmarshal list response: %v", err)
	}

	if len(listResp.Files) == 0 {
		t.Fatal("expected at least 1 file in list, got 0")
	}

	found := false
	for _, f := range listResp.Files {
		if f.Name == "list_test.txt" {
			found = true
			break
		}
	}
	if !found {
		t.Fatal("expected to find list_test.txt in file list")
	}

	if listResp.Total < 1 {
		t.Fatalf("expected total >= 1, got %d", listResp.Total)
	}
	if listResp.Page < 1 {
		t.Fatalf("expected page >= 1, got %d", listResp.Page)
	}
}

func TestIntegration_File_Get(t *testing.T) {
	env := testenv.NewTestEnv(t)

	fileID, _ := env.UploadTestData("get_test.txt", []byte("hello get"))

	resp := env.DoRequest("GET", fmt.Sprintf("/api/v1/files/%d", fileID), nil)
	defer resp.Body.Close()

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

	r := fileDecode(t, resp.Body)
	if !r.Success {
		t.Fatalf("response not success: %s", r.Error)
	}

	var fileResp model.FileResponse
	if err := json.Unmarshal(r.Data, &fileResp); err != nil {
		t.Fatalf("unmarshal file response: %v", err)
	}

	if fileResp.ID != fileID {
		t.Fatalf("expected file ID %d, got %d", fileID, fileResp.ID)
	}
	if fileResp.Name != "get_test.txt" {
		t.Fatalf("expected name get_test.txt, got %s", fileResp.Name)
	}
	if fileResp.Size != int64(len("hello get")) {
		t.Fatalf("expected size %d, got %d", len("hello get"), fileResp.Size)
	}
}

func TestIntegration_File_Download(t *testing.T) {
	env := testenv.NewTestEnv(t)

	content := []byte("hello world")
	fileID, _ := env.UploadTestData("download_test.txt", content)

	resp := env.DoRequest("GET", fmt.Sprintf("/api/v1/files/%d/download", fileID), nil)
	defer resp.Body.Close()

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

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("read download body: %v", err)
	}

	if string(body) != string(content) {
		t.Fatalf("downloaded content mismatch: got %q, want %q", string(body), string(content))
	}

	contentType := resp.Header.Get("Content-Type")
	if contentType == "" {
		t.Fatal("expected Content-Type header to be set")
	}
}

func TestIntegration_File_Delete(t *testing.T) {
	env := testenv.NewTestEnv(t)

	fileID, _ := env.UploadTestData("delete_test.txt", []byte("hello delete"))

	// Delete the file.
	resp := env.DoRequest("DELETE", fmt.Sprintf("/api/v1/files/%d", fileID), nil)
	defer resp.Body.Close()

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

	r := fileDecode(t, resp.Body)
	if !r.Success {
		t.Fatalf("delete response not success: %s", r.Error)
	}

	// Verify the file is gone — GET should return 500 (internal error) or 404.
	getResp := env.DoRequest("GET", fmt.Sprintf("/api/v1/files/%d", fileID), nil)
	defer getResp.Body.Close()

	if getResp.StatusCode == http.StatusOK {
		gr := fileDecode(t, getResp.Body)
		if gr.Success {
			t.Fatal("expected file to be deleted, but GET still returns success")
		}
	}
}