// ---------------------------------------------------------------------------
// Workflow discovery: snapshot IDs, build agent outcome, extract IDs from messages
// ---------------------------------------------------------------------------

import type { InstanceAiAgentNode, InstanceAiMessage } from '@n8n/api-types';

import type { N8nClient, WorkflowResponse } from '../clients/n8n-client';
import type { AgentOutcome, EventOutcome, ExecutionSummary, WorkflowSummary } from '../types';

// ---------------------------------------------------------------------------
// Tool names whose results contain workflow IDs
// ---------------------------------------------------------------------------

const WORKFLOW_TOOLS = new Set([
	'build-workflow',
	'submit-workflow',
	'patch-workflow',
	'build-workflow-with-agent',
]);

// ---------------------------------------------------------------------------
// snapshotWorkflowIds -- call before the run to know what existed prior
// ---------------------------------------------------------------------------

export async function snapshotWorkflowIds(client: N8nClient): Promise<Set<string>> {
	try {
		const workflows = await client.listWorkflows();
		return new Set(workflows.map((wf) => wf.id));
	} catch {
		return new Set();
	}
}

// ---------------------------------------------------------------------------
// buildAgentOutcome
// ---------------------------------------------------------------------------

export async function buildAgentOutcome(
	client: N8nClient,
	eventOutcome: EventOutcome,
	preRunWorkflowIds?: Set<string>,
	claimedWorkflowIds?: Set<string>,
): Promise<AgentOutcome> {
	const workflowsCreated: WorkflowSummary[] = [];
	const workflowJsons: WorkflowResponse[] = [];
	const executionsRun: ExecutionSummary[] = [];

	// Collect workflow IDs from events
	const knownWfIds = new Set(eventOutcome.workflowIds);

	// Mark event-based workflow IDs as claimed so concurrent runs skip them
	if (claimedWorkflowIds) {
		for (const id of knownWfIds) {
			claimedWorkflowIds.add(id);
		}
	}

	// Diff against pre-run snapshot to find workflows created by background tasks
	// that didn't surface in the SSE events we parsed.
	// When running concurrently, skip workflows already claimed by another run.
	if (preRunWorkflowIds) {
		try {
			const currentWorkflows = await client.listWorkflows();
			for (const wf of currentWorkflows) {
				if (
					!preRunWorkflowIds.has(wf.id) &&
					!knownWfIds.has(wf.id) &&
					!claimedWorkflowIds?.has(wf.id)
				) {
					knownWfIds.add(wf.id);
					claimedWorkflowIds?.add(wf.id);
				}
			}
		} catch {
			// Non-fatal -- fall back to event-based IDs only
		}
	}

	// Fetch workflow details
	for (const wfId of knownWfIds) {
		try {
			const wf = await client.getWorkflow(wfId);
			workflowsCreated.push({
				id: wfId,
				name: wf.name,
				nodeCount: wf.nodes.length,
				active: wf.active,
			});
			workflowJsons.push(wf);
		} catch {
			// Workflow may have been deleted or is inaccessible
			workflowsCreated.push({
				id: wfId,
				name: '(fetch failed)',
				nodeCount: 0,
				active: false,
			});
		}
	}

	// Fetch execution details
	for (const execId of eventOutcome.executionIds) {
		try {
			const executions = await client.listExecutions();
			const match = executions.find((e) => e.id === execId);
			if (match) {
				executionsRun.push({
					id: match.id,
					workflowId: match.workflowId,
					status: match.status,
				});
			} else {
				executionsRun.push({
					id: execId,
					workflowId: 'unknown',
					status: 'not-found',
				});
			}
		} catch {
			executionsRun.push({
				id: execId,
				workflowId: 'unknown',
				status: 'fetch-failed',
			});
		}
	}

	return {
		workflowsCreated,
		executionsRun,
		dataTablesCreated: eventOutcome.dataTableIds,
		finalText: eventOutcome.finalText,
		workflowJsons,
	};
}

// ---------------------------------------------------------------------------
// extractWorkflowIdsFromMessages
//
// Extracts workflow IDs from agent tree targetResource fields AND from
// tool call results (build-workflow, submit-workflow, etc.).
// Thread-scoped -- avoids cross-run workflow attribution.
// ---------------------------------------------------------------------------

export function extractWorkflowIdsFromMessages(messages: InstanceAiMessage[]): string[] {
	const ids = new Set<string>();

	for (const message of messages) {
		if (message.role === 'assistant' && message.agentTree) {
			collectWorkflowIds(message.agentTree, ids);
		}
	}

	return [...ids];
}

// ---------------------------------------------------------------------------
// Internal helpers
// ---------------------------------------------------------------------------

function collectWorkflowIds(node: InstanceAiAgentNode, ids: Set<string>): void {
	if (node.targetResource?.type === 'workflow' && node.targetResource.id) {
		ids.add(node.targetResource.id);
	}

	// Extract workflow IDs from tool call results
	for (const tc of node.toolCalls) {
		if (WORKFLOW_TOOLS.has(tc.toolName)) {
			const id = extractIdFromResult(tc.result);
			if (id) ids.add(id);
		}
	}

	for (const child of node.children) {
		collectWorkflowIds(child, ids);
	}
}

function isRecord(value: unknown): value is Record<string, unknown> {
	return typeof value === 'object' && value !== null && !Array.isArray(value);
}

function extractIdFromResult(result: unknown): string | undefined {
	const keys = ['workflowId', 'id'];

	if (!isRecord(result)) {
		if (typeof result === 'string') {
			try {
				const parsed: unknown = JSON.parse(result);
				if (isRecord(parsed)) {
					return extractIdFromRecord(parsed, keys);
				}
			} catch {
				return undefined;
			}
		}
		return undefined;
	}
	return extractIdFromRecord(result, keys);
}

function extractIdFromRecord(record: Record<string, unknown>, keys: string[]): string | undefined {
	for (const key of keys) {
		const value = record[key];
		if (typeof value === 'string' && value.length > 0) {
			return value;
		}
		if (typeof value === 'number') {
			return String(value);
		}
	}
	return undefined;
}