import { isDid } from "@atcute/lexicons/syntax";
import type { Component } from "svelte";
import type { SvelteHTMLElements } from "svelte/elements";
import AtSign from "$icon/at-sign";
import Ban from "$icon/ban";
import CircleDot from "$icon/circle-dot";
import GitMerge from "$icon/git-merge";
import GitPullRequestClosed from "$icon/git-pull-request-closed";
import GitPullRequestCreate from "$icon/git-pull-request-create";
import MessageSquare from "$icon/message-square";
import Star from "$icon/star";
import UserPlus from "$icon/user-plus";
import UserRoundMinus from "$icon/user-round-minus";
import UserRoundArrowForward from "#lib/components/icons/UserRoundArrowForward.svelte";
import { profileIdentifier } from "#lib/api/identity.ts";
import type {
	NotificationCategory,
	NotificationSummary,
	NotificationType
} from "#lib/components/notifications/types.ts";

type IconComponent = Component<SvelteHTMLElements["svg"]>;

export const SOCIAL_TYPES: NotificationType[] = ["repo_starred", "followed"];

const CATEGORIES: Record<NotificationType, NotificationCategory> = {
	repo_starred: "social",
	followed: "social",
	issue_created: "work",
	issue_commented: "work",
	issue_closed: "work",
	issue_reopen: "work",
	issue_assigned: "work",
	issue_unassigned: "work",
	pull_created: "work",
	pull_commented: "work",
	pull_merged: "work",
	pull_closed: "work",
	pull_reopen: "work",
	pull_assigned: "work",
	pull_unassigned: "work",
	user_mentioned: "work"
};

const ICONS: Record<NotificationType, IconComponent> = {
	repo_starred: Star,
	followed: UserPlus,
	issue_created: CircleDot,
	issue_commented: MessageSquare,
	issue_closed: Ban,
	issue_reopen: CircleDot,
	issue_assigned: UserRoundArrowForward,
	issue_unassigned: UserRoundMinus,
	pull_created: GitPullRequestCreate,
	pull_commented: MessageSquare,
	pull_merged: GitMerge,
	pull_closed: GitPullRequestClosed,
	pull_reopen: GitPullRequestCreate,
	pull_assigned: UserRoundArrowForward,
	pull_unassigned: UserRoundMinus,
	user_mentioned: AtSign
};

// the design system has no purple, and a merged pull already reads as info on
// TicketStatePill, so merges land on the same token here.
const TONES: Record<NotificationType, string> = {
	repo_starred: "text-foreground-warning",
	followed: "text-foreground-muted",
	issue_created: "text-foreground-success",
	issue_commented: "text-foreground-muted",
	issue_closed: "text-foreground-muted",
	issue_reopen: "text-foreground-success",
	issue_assigned: "text-foreground-info",
	issue_unassigned: "text-foreground-muted",
	pull_created: "text-foreground-success",
	pull_commented: "text-foreground-muted",
	pull_merged: "text-foreground-info",
	pull_closed: "text-foreground-danger",
	pull_reopen: "text-foreground-success",
	pull_assigned: "text-foreground-info",
	pull_unassigned: "text-foreground-muted",
	user_mentioned: "text-foreground-info"
};

const PHRASES: Record<NotificationType, string> = {
	repo_starred: "starred",
	followed: "followed you",
	issue_created: "opened an issue",
	issue_commented: "commented on an issue",
	issue_closed: "closed an issue",
	issue_reopen: "reopened an issue",
	issue_assigned: "assigned you to an issue",
	issue_unassigned: "unassigned you from an issue",
	pull_created: "created a PR",
	pull_commented: "commented on a PR",
	pull_merged: "merged a PR",
	pull_closed: "closed a PR",
	pull_reopen: "reopened a PR",
	pull_assigned: "assigned you to a PR",
	pull_unassigned: "unassigned you from a PR",
	user_mentioned: "mentioned you"
};

export const notificationCategory = (type: NotificationType): NotificationCategory =>
	CATEGORIES[type];

export const notificationIcon = (type: NotificationType): IconComponent => ICONS[type];

export const notificationTone = (type: NotificationType): string => TONES[type];

const basePhrase = (notification: NotificationSummary): string => {
	if (notification.type === "user_mentioned" && notification.subject) {
		return notification.subject.kind === "issue"
			? "mentioned you on an issue"
			: "mentioned you on a pull request";
	}
	return PHRASES[notification.type];
};

const preposition = (type: NotificationType): string => {
	if (type === "repo_starred") return "";
	return type === "user_mentioned" ? " in" : " on";
};

export const notificationPhrase = (
	notification: NotificationSummary,
	leadingRepo = false
): string => {
	const phrase = basePhrase(notification);
	return leadingRepo && notification.repo ? phrase + preposition(notification.type) : phrase;
};

export const notificationTarget = (
	notification: NotificationSummary,
	includingOwner = true
): string => {
	const repo = notification.repo;
	if (!repo) return "";
	return includingOwner ? `${repo.ownerHandle}/${repo.name}` : repo.name;
};

export const notificationHref = (notification: NotificationSummary): string => {
	if (notification.type === "followed")
		return `/${profileIdentifier(notification.actor.handle, notification.actor.did)}`;
	const repo = notification.repo;
	if (!repo) return `/${profileIdentifier(notification.actor.handle, notification.actor.did)}`;
	// did-addressed repos have no name to route on; the did is their address, and
	// issues/pulls under them can't be addressed either
	if (isDid(repo.name)) return `/${repo.name}`;
	const base = `/${repo.ownerHandle}/${repo.name}`;
	const subject = notification.subject;
	if (!subject) return base;
	return `${base}/${subject.kind === "issue" ? "issues" : "pulls"}/${subject.number}`;
};