/**
 * Intent Analyzer — Analyzer
 *
 * Keyword-based intent detection.
 */

import type {
	Intent,
	IntentConfidence,
	IntentKind,
	IntentRule,
	IntentSignal,
} from "./types.js";

const INTENT_RULES: IntentRule[] = [
	{
		kind: "bug_fix",
		keywords: [
			"fix",
			"bug",
			"error",
			"crash",
			"fail",
			"broken",
			"issue",
			"defect",
			"patch",
			"hotfix",
		],
		weight: 2,
		confidence: "high",
	},
	{
		kind: "feature",
		keywords: ["add", "implement", "new", "create", "build", "introduce"],
		weight: 2,
		confidence: "high",
	},
	{
		kind: "refactor",
		keywords: [
			"refactor",
			"rename",
			"move",
			"extract",
			"restructure",
			"cleanup",
			"simplify",
			"rewrite",
		],
		weight: 2,
		confidence: "high",
	},
	{
		kind: "code_review",
		keywords: [
			"review",
			"check code",
			"audit",
			"critique",
			"evaluate",
			"assess",
		],
		weight: 2,
		confidence: "high",
	},
	{
		kind: "deployment",
		keywords: [
			"deploy",
			"release",
			"publish",
			"ship",
			"launch",
			"rollout",
			"promote",
		],
		weight: 2,
		confidence: "high",
	},
	{
		kind: "testing",
		keywords: [
			"test",
			"spec",
			"coverage",
			"unit test",
			"integration test",
			"e2e",
			"specify",
		],
		weight: 2,
		confidence: "high",
	},
	{
		kind: "documentation",
		keywords: [
			"doc",
			"readme",
			"comment",
			"document",
			"guide",
			"changelog",
			"spec",
		],
		weight: 1,
		confidence: "medium",
	},
	{
		kind: "migration",
		keywords: [
			"migrate",
			"convert",
			"port",
			"upgrade",
			"move to",
			"transition",
		],
		weight: 2,
		confidence: "high",
	},
	{
		kind: "security",
		keywords: [
			"security",
			"vulnerability",
			"exploit",
			"auth",
			"permission",
			"cve",
			"secret",
			"token",
		],
		weight: 2,
		confidence: "high",
	},
	{
		kind: "performance",
		keywords: [
			"performance",
			"speed",
			"optimize",
			"fast",
			"slow",
			"latency",
			"benchmark",
		],
		weight: 2,
		confidence: "high",
	},
	{
		kind: "architecture",
		keywords: [
			"architecture",
			"design",
			"structure",
			"system design",
			"pattern",
			"abstraction",
			"component",
		],
		weight: 2,
		confidence: "medium",
	},
	{
		kind: "research",
		keywords: [
			"research",
			"investigate",
			"explore",
			"analyze",
			"study",
			"understand",
		],
		weight: 1,
		confidence: "medium",
	},
	{
		kind: "learning",
		keywords: [
			"learn",
			"teach",
			"explain",
			"how does",
			"understand",
			"what is",
		],
		weight: 1,
		confidence: "low",
	},
];

function tokenize(text: string): string[] {
	return text
		.toLowerCase()
		.replace(/[^a-z0-9\s]/g, " ")
		.split(/\s+/)
		.filter(Boolean);
}

export class IntentAnalyzer {
	private rules: IntentRule[];

	constructor(rules: IntentRule[] = INTENT_RULES) {
		this.rules = rules;
	}

	analyze(text: string): Intent {
		const lower = text.toLowerCase();
		const tokens = tokenize(text);

		const matchedSignals: IntentSignal[] = [];
		let topKind: IntentKind = "general";
		let topScore = 0;
		let topConfidence: IntentConfidence = "low";

		for (const rule of this.rules) {
			let ruleScore = 0;
			const matchedKeywords: string[] = [];

			for (const keyword of rule.keywords) {
				if (lower.includes(keyword)) {
					ruleScore += rule.weight;
					matchedKeywords.push(keyword);
				}
			}

			if (ruleScore > topScore) {
				topScore = ruleScore;
				topKind = rule.kind;
				topConfidence = rule.confidence;
			}

			for (const kw of matchedKeywords) {
				matchedSignals.push({
					keyword: kw,
					weight: rule.weight,
					matched: true,
				});
			}
		}

		if (topScore === 0) {
			topKind = "general";
			topConfidence = "low";
		}

		return {
			kind: topKind,
			confidence: topConfidence,
			signals: matchedSignals,
			originalText: text,
		};
	}

	analyzeBatch(texts: string[]): Intent[] {
		return texts.map((t) => this.analyze(t));
	}
}