package ai.dynamixs.mcp;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import jakarta.json.Json;
import jakarta.json.JsonObject;
import jakarta.json.JsonObjectBuilder;

/**
 * Represents an MCP Tool based on Imixs-Workflow BPMN models.
 * 
 * MCP Tools represent functions that can be called by the MCP client. Each tool
 * corresponds to a workflow task/event combination.
 */
public class MCPTool implements Serializable {

    private static final long serialVersionUID = 1L;

    // MCP Standard Fields
    private String name;                        // Tool name/identifier
    private String description;                 // Tool description
    private JsonObject inputSchema;             // JSON Schema for input parameters

    // Imixs-specific fields
    private String modelVersion;
    private int taskId;
    private int eventId;
    private List<String> tags;
    private List<String> examples;

    // Constructors
    public MCPTool() {
        this.tags = new ArrayList<>();
        this.examples = new ArrayList<>();
    }

    public MCPTool(String modelVersion, int taskId, int eventId) {
        this();
        this.modelVersion = modelVersion;
        this.taskId = taskId;
        this.eventId = eventId;
        this.name = createToolName(modelVersion, taskId, eventId);
    }

    /**
     * Creates a tool name from Imixs workflow components
     */
    public static String createToolName(String modelVersion, int taskId, int eventId) {
        if (modelVersion == null || modelVersion.trim().isEmpty()) {
            throw new IllegalArgumentException("Model version cannot be null or empty");
        }
        return String.format("%s_%d_%d", modelVersion.replace("-", "_"), taskId, eventId);
    }

    /**
     * Parses model version from tool name
     */
    public String getModelVersionFromName() {
        if (name == null || !name.contains("_")) {
            throw new IllegalStateException("Invalid tool name format: " + name);
        }
        return name.substring(0, name.lastIndexOf('_', name.lastIndexOf('_') - 1)).replace("_", "-");
    }

    /**
     * Parses task ID from tool name
     */
    public int getTaskIdFromName() {
        if (name == null || !name.contains("_")) {
            throw new IllegalStateException("Invalid tool name format: " + name);
        }
        String[] parts = name.split("_");
        if (parts.length < 3) {
            throw new IllegalStateException("Invalid tool name format: " + name);
        }
        try {
            return Integer.parseInt(parts[parts.length - 2]);
        } catch (NumberFormatException e) {
            throw new IllegalStateException("Invalid task ID in tool name: " + name, e);
        }
    }

    /**
     * Parses event ID from tool name
     */
    public int getEventIdFromName() {
        if (name == null || !name.contains("_")) {
            throw new IllegalStateException("Invalid tool name format: " + name);
        }
        String[] parts = name.split("_");
        if (parts.length < 3) {
            throw new IllegalStateException("Invalid tool name format: " + name);
        }
        try {
            return Integer.parseInt(parts[parts.length - 1]);
        } catch (NumberFormatException e) {
            throw new IllegalStateException("Invalid event ID in tool name: " + name, e);
        }
    }

    /**
     * Creates a default input schema for workflow tools
     */
    public JsonObject createDefaultInputSchema() {
        return Json.createObjectBuilder()
                .add("type", "object")
                .add("properties", Json.createObjectBuilder()
                        .add("workitem", Json.createObjectBuilder()
                                .add("type", "object")
                                .add("description", "Workflow item data")
                                .add("properties", Json.createObjectBuilder()
                                        .add("$modelversion", Json.createObjectBuilder()
                                                .add("type", "string")
                                                .add("description", "Workflow model version")
                                                .build())
                                        .add("$taskid", Json.createObjectBuilder()
                                                .add("type", "integer")
                                                .add("description", "Task ID")
                                                .build())
                                        .add("$eventid", Json.createObjectBuilder()
                                                .add("type", "integer")
                                                .add("description", "Event ID")
                                                .build())
                                        .build())
                                .add("required", Json.createArrayBuilder()
                                        .add("$modelversion")
                                        .add("$taskid")
                                        .add("$eventid")
                                        .build())
                                .build())
                        .build())
                .add("required", Json.createArrayBuilder()
                        .add("workitem")
                        .build())
                .build();
    }

    /**
     * Converts this tool to MCP JSON format
     */
    public JsonObject toJsonObject() {
        JsonObjectBuilder builder = Json.createObjectBuilder()
                .add("name", name != null ? name : "")
                .add("description", description != null ? description : "");

        // Input schema
        if (inputSchema != null) {
            builder.add("inputSchema", inputSchema);
        } else {
            builder.add("inputSchema", createDefaultInputSchema());
        }

        return builder.build();
    }

    /**
     * Creates an MCPTool from a JsonObject
     */
    public static MCPTool fromJsonObject(JsonObject jsonObject) {
        MCPTool tool = new MCPTool();

        tool.setName(jsonObject.getString("name", ""));
        tool.setDescription(jsonObject.getString("description", ""));

        if (jsonObject.containsKey("inputSchema")) {
            tool.setInputSchema(jsonObject.getJsonObject("inputSchema"));
        }

        return tool;
    }

    /**
     * Validates this tool for MCP compliance
     */
    public boolean isValid() {
        if (name == null || name.trim().isEmpty()) {
            return false;
        }

        if (description == null || description.trim().isEmpty()) {
            return false;
        }

        // Validate tool name format
        try {
            getModelVersionFromName();
            getTaskIdFromName();
            getEventIdFromName();
        } catch (Exception e) {
            return false;
        }

        return true;
    }

    // Getters and Setters
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public JsonObject getInputSchema() {
        return inputSchema;
    }

    public void setInputSchema(JsonObject inputSchema) {
        this.inputSchema = inputSchema;
    }

    public String getModelVersion() {
        return modelVersion;
    }

    public void setModelVersion(String modelVersion) {
        this.modelVersion = modelVersion;
    }

    public int getTaskId() {
        return taskId;
    }

    public void setTaskId(int taskId) {
        this.taskId = taskId;
    }

    public int getEventId() {
        return eventId;
    }

    public void setEventId(int eventId) {
        this.eventId = eventId;
    }

    public List<String> getTags() {
        return tags;
    }

    public void setTags(List<String> tags) {
        this.tags = tags != null ? tags : new ArrayList<>();
    }

    public List<String> getExamples() {
        return examples;
    }

    public void setExamples(List<String> examples) {
        this.examples = examples != null ? examples : new ArrayList<>();
    }

    @Override
    public String toString() {
        return String.format("MCPTool{name='%s', description='%s', modelVersion='%s', taskId=%d, eventId=%d}",
                name, description, modelVersion, taskId, eventId);
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null || getClass() != obj.getClass())
            return false;
        MCPTool that = (MCPTool) obj;
        return name != null ? name.equals(that.name) : that.name == null;
    }

    @Override
    public int hashCode() {
        return name != null ? name.hashCode() : 0;
    }
}