package tools

import (
	"context"
	"fmt"
	"strings"
	"time"

	"github.com/modelcontextprotocol/go-sdk/mcp"

	"isphere-ai-bridge/internal/isphere"
)

const ToolNameReceiveFiles = "isphere_receive_files"

type ReceiveFilesArgs struct {
	ConversationID string `json:"conversation_id,omitempty" jsonschema:"conversation id filter for file listing"`
	MessageID      string `json:"message_id,omitempty" jsonschema:"message id filter for file listing"`
	FileID         string `json:"file_id,omitempty" jsonschema:"file id filter for file listing"`
	NameContains   string `json:"name_contains,omitempty" jsonschema:"case-insensitive filename substring filter"`
	Mode           string `json:"mode,omitempty" jsonschema:"file receive mode; C14 supports list only"`
	Limit          int    `json:"limit,omitempty" jsonschema:"maximum number of files to return; zero or negative returns all matches"`
}

func RegisterISphereFileTools(server *mcp.Server, source ReceiveMessagesSource) {
	if source == nil {
		source = isphere.EncryptedPacketLogSource{}
	}

	mcp.AddTool[ReceiveFilesArgs, map[string]any](server, &mcp.Tool{
		Name:        ToolNameReceiveFiles,
		Description: "List iSphere file metadata candidates from the configured read-only message source; download is deferred until cache mapping is validated.",
	}, func(ctx context.Context, _ *mcp.CallToolRequest, input ReceiveFilesArgs) (*mcp.CallToolResult, map[string]any, error) {
		started := time.Now().UTC()
		mode := strings.ToLower(strings.TrimSpace(input.Mode))
		if mode == "" {
			mode = "list"
		}
		if mode != "list" {
			return nil, nil, fmt.Errorf("isphere_receive_files mode %q is not available; only list is supported", input.Mode)
		}
		messages, err := source.ReceiveMessages(ctx, isphere.ReceiveMessagesQuery{Limit: 0})
		if err != nil {
			return nil, nil, err
		}
		files := isphere.ListFilesFromMessages(messages.Messages, isphere.ListFilesQuery{
			ConversationID: input.ConversationID,
			MessageID:      input.MessageID,
			FileID:         input.FileID,
			NameContains:   input.NameContains,
			Limit:          input.Limit,
		})
		return nil, receiveFilesResultToMap(files, started, time.Now().UTC()), nil
	})
}

func receiveFilesResultToMap(result isphere.ListFilesResult, started time.Time, finished time.Time) map[string]any {
	files := make([]map[string]any, 0, len(result.Files))
	for _, file := range result.Files {
		files = append(files, map[string]any{
			"file_id":         file.FileID,
			"message_id":      nullableString(file.MessageID),
			"conversation_id": nullableString(file.ConversationID),
			"file_name":       file.FileName,
			"size_bytes":      file.SizeBytes,
			"mime_type":       file.MimeType,
			"created_at":      nullableString(file.CreatedAt),
			"download_ref":    nullableString(file.DownloadRef),
			"saved_path":      nullableString(file.SavedPath),
			"sha256":          nullableString(file.SHA256),
			"source":          file.Source,
			"raw_ref":         file.RawRef,
		})
	}
	return map[string]any{
		"ok":          true,
		"mode":        "list",
		"files":       files,
		"next_cursor": nil,
		"audit": map[string]any{
			"tool":           ToolNameReceiveFiles,
			"source":         "local_readonly",
			"execution_mode": "read",
			"started_at":     started.Format(time.RFC3339Nano),
			"finished_at":    finished.Format(time.RFC3339Nano),
			"result":         "ok",
		},
	}
}

func nullableString(value string) any {
	if strings.TrimSpace(value) == "" {
		return nil
	}
	return value
}