import { Enumeration, Num, OpenAPIRoute } from "chanfana";
import { z } from "zod";
import { type AppContext } from "../types";

export class CondenseTextEndpoint extends OpenAPIRoute {
	schema = {
		tags: ["Processing"],
		summary: "Condense a given text based on a directive",
		security: [
			{
				apiKey: [],
			},
		],
		request: {
			body: {
				content: {
					"application/json": {
						schema: z.object({
							text: z.string({
								description: "The text to be condensed.",
								required_error:
									"Text is required for condensation.",
							}).min(1, "Text cannot be empty."),
							mediaType: z.enum(["video", "image"], {
								description:
									"The type of media being described",
								required_error: "Media type is required.",
							}),
						}),
					},
				},
			},
		},
		responses: {
			"200": {
				description: "Returns the condensed text",
				content: {
					"application/json": {
						schema: z.object({
							success: z.boolean(),
							condensedText: z.string().nullable(),
							error: z.string().optional(),
						}),
					},
				},
			},
			"500": {
				description:
					"Internal Server Error - Issue with Cloud Function or API call",
				content: {
					"application/json": {
						schema: z.object({
							success: z.boolean(),
							message: z.string(),
						}),
					},
				},
			},
		},
	};

	async handle(c: AppContext) {
		const data = await this.getValidatedData<typeof this.schema>();
		const { text, mediaType } = data.body;

		const targetLength = c.env.MAX_ALT_TEXT_LENGTH - 100;

		try {
			const res = await c.var.gemini.models.generateContent({
				// * Original cloud function used "gemini-2.0-flash", but I think the lite version should work fine too.
				model: "gemini-2.0-flash-lite",
				contents: [{
					parts: [
						{
							text:
								`You are an expert at writing concise, informative alt text. Please condense the following ${mediaType} description to be no more than ${targetLength} characters while preserving the most important details. The description needs to be accessible and useful for screen readers:`,
						},
						{ text: text },
					],
				}],
				config: {
					temperature: 0.2,
					maxOutputTokens: 1024,
				},
			});

			const condensedText = res.candidates?.[0]?.content?.parts?.[0]
				?.text;
			if (!condensedText) {
				return {
					success: false,
					error: "Failed to condense text.",
				};
			}

			return {
				success: true,
				altText: condensedText,
			};
		} catch (e) {
			return {
				success: false,
				message: e,
			};
		}
	}
}