import { log } from "@clack/prompts";

import { command, flag, option, optional, string } from "cmd-ts";

import { glob } from "glob";

import * as fs from "node:fs/promises";

import * as path from "node:path";

import {

	findConfig,

	loadConfig,

	loadState,

	DEFAULT_PUBLISHER_CONFIG,

} from "../lib/config";

export const injectCommand = command({

	name: "inject",

	description: "Inject site.standard.document link tags into built HTML files",

	args: {

		outputDir: option({

			long: "output",

			short: "o",

			description: "Output directory to scan for HTML files",

			type: optional(string),

		}),

		dryRun: flag({

			long: "dry-run",

			short: "n",

			description: "Preview what would be injected without making changes",

		}),

	},

	handler: async ({ outputDir: outputDirArg, dryRun }) => {

		// Load config

		const configPath = await findConfig();

		if (!configPath) {

			log.error("No sequoia.json found. Run 'sequoia init' first.");

			process.exit(1);

		}

		const config = await loadConfig(configPath);

		const configDir = path.dirname(configPath);

		// Determine output directory

		const outputDir =

			outputDirArg || config.outputDir || DEFAULT_PUBLISHER_CONFIG.outputDir;

		const resolvedOutputDir = path.isAbsolute(outputDir)

			? outputDir

			: path.join(configDir, outputDir);

		log.info(`Scanning for HTML files in: ${resolvedOutputDir}`);

		// Load state to get atUri mappings

		const state = await loadState(configDir);

		// Build a map of slug to atUri from state

		// The slug is stored in state by the publish command, using the configured slug options

		const slugToAtUri = new Map<string, string>();

		for (const [filePath, postState] of Object.entries(state.posts)) {

			if (postState.atUri && postState.slug) {

				// Use the slug stored in state (computed by publish with config options)

				slugToAtUri.set(postState.slug, postState.atUri);

				// Also add the last segment for simpler matching

				// e.g., "other/my-other-post" -> also map "my-other-post"

				const lastSegment = postState.slug.split("/").pop();

				if (lastSegment && lastSegment !== postState.slug) {

					slugToAtUri.set(lastSegment, postState.atUri);

				}

			} else if (postState.atUri) {

				// Fallback for older state files without slug field

				// Extract slug from file path (e.g., ./content/blog/my-post.md -> my-post)

				const basename = path.basename(filePath, path.extname(filePath));

				slugToAtUri.set(basename.toLowerCase(), postState.atUri);

			}

		}

		if (slugToAtUri.size === 0) {

			log.warn(

				"No published posts found in state. Run 'sequoia publish' first.",

			);

			return;

		}

		log.info(`Found ${slugToAtUri.size} slug mappings from published posts`);

		// Scan for HTML files

		const htmlFiles = await glob("**/*.html", {

			cwd: resolvedOutputDir,

			absolute: false,

		});

		if (htmlFiles.length === 0) {

			log.warn(`No HTML files found in ${resolvedOutputDir}`);

			return;

		}

		log.info(`Found ${htmlFiles.length} HTML files`);

		let injectedCount = 0;

		let skippedCount = 0;

		let alreadyHasCount = 0;

		for (const file of htmlFiles) {

			const htmlPath = path.join(resolvedOutputDir, file);

			// Try to match this HTML file to a published post

			const relativePath = file;

			const htmlDir = path.dirname(relativePath);

			const htmlBasename = path.basename(relativePath, ".html");

			// Try different matching strategies

			let atUri: string | undefined;

			// Strategy 1: Direct basename match (e.g., my-post.html -> my-post)

			atUri = slugToAtUri.get(htmlBasename);

			// Strategy 2: For index.html, try the directory path

			// e.g., posts/40th-puzzle-box/what-a-gift/index.html -> 40th-puzzle-box/what-a-gift

			if (!atUri && htmlBasename === "index" && htmlDir !== ".") {

				// Try full directory path (for nested subdirectories)

				atUri = slugToAtUri.get(htmlDir);

				// Also try just the last directory segment

				if (!atUri) {

					const lastDir = path.basename(htmlDir);

					atUri = slugToAtUri.get(lastDir);

				}

			}

			// Strategy 3: Full path match (e.g., blog/my-post.html -> blog/my-post)

			if (!atUri && htmlDir !== ".") {

				atUri = slugToAtUri.get(`${htmlDir}/${htmlBasename}`);

			}

			if (!atUri) {

				skippedCount++;

				continue;

			}

			// Read the HTML file

			let content = await fs.readFile(htmlPath, "utf-8");

			// Inject the tags

			const injected = injectLinkTags(

				dryRun,

				relativePath,

				content,

				atUri,

				config.publicationUri,

			);

			switch (injected) {

				case Injected.AlreadyPresent:

					alreadyHasCount++;

					continue;

				case Injected.Skipped:

					skippedCount++;

					continue;

				case Injected.Faked:

					injectedCount++;

					continue;

				default:

					content = injected;

			}

			await fs.writeFile(htmlPath, content);

			log.success(`  Injected into: ${relativePath}`);

			injectedCount++;

		}

		// Summary

		log.message("\n---");

		if (dryRun) {

			log.info("Dry run complete. No changes made.");

		}

		log.info(`Injected: ${injectedCount}`);

		log.info(`Already has tag: ${alreadyHasCount}`);

		log.info(`Skipped (no match): ${skippedCount}`);

		if (skippedCount > 0 && !dryRun) {

			log.info(

				"\nTip: Skipped files had no matching published post. This is normal for non-post pages.",

			);

		}

	},

});

export enum Injected {

	AlreadyPresent = 0,

	Skipped,

	Faked,

}

export function injectLinkTags(

	dryRun: boolean,

	relativePath: string,

	content: string,

	atUri: string,

	publicationUri: string,

): string | Injected {

	// Check if link tags already exist

	let documentLinkTag: string | undefined =

		`<link rel="site.standard.document" href="${atUri}">`;

	let publicationLinkTag: string | undefined =

		`<link rel="site.standard.publication" href="${publicationUri}">`;

	if (content.includes('rel="site.standard.document"')) {

		documentLinkTag = undefined;

	}

	if (content.includes('rel="site.standard.publication"')) {

		publicationLinkTag = undefined;

	}

	if (!documentLinkTag && !publicationLinkTag) {

		return Injected.AlreadyPresent;

	}

	// Find </head> and inject before it

	const headCloseIndex = content.indexOf("</head>");

	if (headCloseIndex === -1) {

		log.warn(`  No </head> found in ${relativePath}, skipping`);

		return Injected.Skipped;

	}

	if (dryRun) {

		log.message(`  Would inject into: ${relativePath}`);

		if (documentLinkTag) {

			log.message(`    ${documentLinkTag}`);

		}

		if (publicationLinkTag) {

			log.message(`    ${publicationLinkTag}`);

		}

		return Injected.Faked;

	}

	// Inject the link tags

	const indent = "  "; // Standard indentation

	const after = content.slice(headCloseIndex);

	content = content.slice(0, headCloseIndex);

	if (documentLinkTag) {

		content += `${indent}${documentLinkTag}\n${indent}`;

	}

	if (publicationLinkTag) {

		content += `${indent}${publicationLinkTag}\n${indent}`;

	}

	content += after;

	return content;

}