/**
 * Copyright (c) 2026, Salesforce, Inc.,
 * All rights reserved.
 * For full license text, see the LICENSE.txt file
 */

import { getSessionSchema } from "./query-helpers.js";
import { formatHelp } from "../lib/query-commands.js";
import {
	loadSession,
	getNavigationContext,
	isInArgsContext,
	queryNavToSchemaPath,
	getArgsFieldPath,
	getInputSubPath,
	parseVariablePath,
} from "../lib/session.js";
import { formatPath } from "../lib/session.js";
import {
	getRootFields,
	resolveArgByName,
	resolveInputPath,
	resolvePath,
	type InputWalkerResult,
} from "../lib/walker.js";

export function queryExample(sessionId: string): void {
	const session = loadSession(sessionId);
	const ctx = getNavigationContext(session.navigationPath);
	const schema = getSessionSchema(session);

	if (ctx === "root" || session.navigationPath.length === 0) {
		console.log("At root. Navigate into query/ or variables/:");
		console.log("  cd query          — build the query projection");
		console.log("  cd variables      — manage query variables");
		return;
	}

	if (ctx === "variables") {
		const varParsed = parseVariablePath(session.navigationPath);
		if (!varParsed) {
			console.log("Define and manage query variables:");
			console.log("  define $filter AccountWhere      — create with explicit type");
			console.log("  define $limit Int 10             — with a default value");
			console.log("  define $filter @args/where       — auto-infer type from a path");
			console.log("  cd $filter                       — navigate into a complex variable");
			console.log("  assign $limit 10                 — set a scalar variable value");
			return;
		}
		const variable = session.variables.find((v) => v.name === varParsed.varName);
		if (!variable) return;
		const rawType = variable.type.replace(/[![\]]/g, "");
		const inputResult = resolveInputPath(schema, rawType, varParsed.inputSubPath);
		printInputExamples(inputResult, "assign");
		return;
	}

	if (isInArgsContext(session.navigationPath)) {
		const fieldSchemaPath = getArgsFieldPath(session.navigationPath);
		const inputSubPath = getInputSubPath(session.navigationPath);
		const wr = resolvePath(schema, session.operation, fieldSchemaPath);

		if (inputSubPath.length === 0) {
			console.log(`Arguments for field at ${formatPath(fieldSchemaPath)}:`);
			for (const arg of wr.args) {
				const isLeaf = arg.typeKind === "SCALAR" || arg.typeKind === "ENUM";
				if (isLeaf) {
					console.log(`  assign ${arg.name} <value>       — ${arg.typeName}`);
				} else {
					console.log(`  cd ${arg.name}                   — navigate into ${arg.typeName}`);
					console.log(`  assign ${arg.name} $var           — or bind a variable`);
				}
			}
			console.log("");
			console.log("  define $varName @args/where      — auto-infer type and bind");
			console.log("  define $varName                  — auto-infer from current arg (after cd)");
			return;
		}

		const argName = inputSubPath[0];
		const argInfo = resolveArgByName(schema, wr, argName);
		const rawType = argInfo.typeName;
		const remaining = inputSubPath.slice(1);
		const inputResult = resolveInputPath(schema, rawType, remaining);
		printInputExamples(inputResult, "assign");
		console.log("");
		console.log("  define $varName                  — auto-infer type and bind to this position");
		return;
	}

	const schemaPath = queryNavToSchemaPath(session.navigationPath);
	if (schemaPath.length === 0) {
		const rootFields = getRootFields(schema, session.operation);
		console.log("Navigate into a field:");
		for (const f of rootFields.slice(0, 5)) {
			console.log(`  cd ${f.name}`);
		}
		return;
	}

	const wr = resolvePath(schema, session.operation, schemaPath);

	console.log("Select leaf fields:");
	const leaves = wr.fields.filter((f) => f.typeKind === "SCALAR" || f.typeKind === "ENUM");
	for (const f of leaves.slice(0, 5)) {
		const alias = f.name.charAt(0).toLowerCase() + f.name.slice(1);
		console.log(`  select ${f.name}:${alias}`);
	}

	const dirs = wr.fields.filter((f) => f.typeKind !== "SCALAR" && f.typeKind !== "ENUM");
	if (dirs.length > 0) {
		console.log("");
		console.log("Navigate into directories:");
		for (const f of dirs.slice(0, 3)) {
			console.log(`  cd ${f.name}`);
		}
	}

	if (wr.args.length > 0) {
		console.log("");
		console.log("Configure arguments:");
		console.log("  cd @args");
	}

	console.log("");
	console.log("Create aliased instances:");
	if (wr.fields.length > 0) {
		const f = dirs[0] ?? wr.fields[0];
		console.log(`  mkdir myAlias ${f.name}`);
	}
}

export function printInputExamples(inputResult: InputWalkerResult, cmd: string): void {
	if (inputResult.isList) {
		console.log("List type — add elements with mkdir:");
		console.log("  mkdir            — add a new element");
		console.log("  cd 0             — navigate into element 0");
		return;
	}

	const leaves = inputResult.inputFields.filter(
		(f) => f.typeKind === "SCALAR" || f.typeKind === "ENUM",
	);
	const objs = inputResult.inputFields.filter(
		(f) => f.typeKind !== "SCALAR" && f.typeKind !== "ENUM",
	);

	if (leaves.length > 0) {
		console.log("Assign scalar fields:");
		for (const f of leaves.slice(0, 5)) {
			console.log(`  ${cmd} ${f.name} <value>        — ${f.typeName}`);
		}
	}
	if (objs.length > 0) {
		console.log("Navigate into nested types:");
		for (const f of objs.slice(0, 3)) {
			console.log(`  cd ${f.name}                   — ${f.typeName}`);
		}
	}
}

export function queryHelp(sessionId: string | undefined, topic?: string): void {
	if (sessionId) {
		try {
			loadSession(sessionId);
		} catch {
			// Ignore — still show help even for invalid sessions.
		}
	}
	console.log(formatHelp(topic));
}