/**
 * Zod validation schemas for all API routes.
 * Centralizes input validation so every route has consistent,
 * type-safe request body parsing with XSS protection.
 */
import { z } from "zod/v4"

// ── XSS Sanitization ─────────────────────────────────────────────────────

/**
 * Strip dangerous HTML/script patterns from user input.
 * Allows basic text but removes script tags, event handlers, and data URIs.
 */
function sanitizeHtml(input: string): string {
    return input
        // Remove script tags and their content
        .replace(/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi, '')
        // Remove event handlers (onclick, onerror, etc.)
        .replace(/\s*on\w+\s*=\s*["'][^"']*["']/gi, '')
        .replace(/\s*on\w+\s*=\s*[^\s>]*/gi, '')
        // Remove javascript: and data: URIs
        .replace(/javascript\s*:/gi, '')
        .replace(/data\s*:\s*text\/html/gi, '')
        // Remove iframe, object, embed tags
        .replace(/<(iframe|object|embed|applet|form)\b[^>]*>/gi, '')
        .replace(/<\/(iframe|object|embed|applet|form)>/gi, '')
}

/** Zod transform that sanitizes string input */
const sanitizedString = (maxLen: number) =>
    z.string().max(maxLen).transform(sanitizeHtml)

const sanitizedText = (maxLen: number) =>
    z.string().max(maxLen).transform(sanitizeHtml)

// ── Prompts ──────────────────────────────────────────────────────────────

const validCategories = ["Content", "Development", "Marketing", "Business", "Education", "Creative", "Research"] as const

export const createPromptSchema = z.object({
    title: z.string().min(1).max(200).transform(sanitizeHtml),
    description: sanitizedText(2000).optional(),
    template: z.string().min(1).max(50000), // Template is code — don't sanitize (rendered in code blocks)
    schema: z.record(z.string(), z.unknown()).optional(),
    category: z.enum(validCategories).optional(),
    tags: z.array(z.string().max(50).transform(sanitizeHtml)).max(20).optional(),
    modelDefault: z.string().max(100).optional(),
    visibility: z.enum(["public", "unlisted", "private"]).optional(),
})

// ── Collections ──────────────────────────────────────────────────────────

export const createCollectionSchema = z.object({
    name: z.string().min(1).max(200).transform(sanitizeHtml),
    description: sanitizedText(2000).optional(),
    isPublic: z.boolean().optional(),
})

export const updateCollectionSchema = z.object({
    id: z.string().min(1),
    name: z.string().min(1).max(200).transform(sanitizeHtml).optional(),
    description: sanitizedText(2000).optional(),
    isPublic: z.boolean().optional(),
})

// ── Profile ──────────────────────────────────────────────────────────────

export const updateProfileSchema = z.object({
    name: sanitizedString(100).optional(),
    username: z.string().min(3).max(40).regex(/^[a-zA-Z0-9_-]+$/, "Username can only contain letters, numbers, hyphens, underscores").optional(),
    bio: sanitizedText(500).optional(),
    socialLinks: z.record(z.string(), z.string().url()).optional(),
    image: z.string().url().max(2000).optional(),
    notifyEmail: z.boolean().optional(),
    notifyStars: z.boolean().optional(),
    notifyRemixes: z.boolean().optional(),
})

export const syncProfileSchema = z.object({
    id: z.string().min(1),
    email: z.string().email(),
    name: sanitizedString(100).optional(),
    image: z.string().url().max(2000).optional(),
})

// ── Votes ────────────────────────────────────────────────────────────────

export const voteSchema = z.object({
    targetType: z.enum(["imagePrompt", "character"]),
    targetId: z.string().min(1),
    value: z.number().int().min(-1).max(1).optional().default(1),
})

// ── Comments ─────────────────────────────────────────────────────────────

export const createCommentSchema = z.object({
    promptId: z.string().min(1),
    content: z.string().min(1).max(5000).transform(sanitizeHtml),
    parentId: z.string().optional(),
})

export const updateCommentSchema = z.object({
    commentId: z.string().min(1),
    action: z.enum(["like", "unlike", "edit"]),
    content: z.string().min(1).max(5000).transform(sanitizeHtml).optional(),
})

// ── Engagement ───────────────────────────────────────────────────────────

export const engagementSchema = z.object({
    targetType: z.enum(["prompt", "imagePrompt", "character", "workflow"]),
    targetId: z.string().min(1),
    action: z.enum(["view", "use", "save", "share", "copy"]),
})

// ── Forum ────────────────────────────────────────────────────────────────

const forumCategories = ["general", "help", "showcase", "feature-request", "tips"] as const

export const createForumPostSchema = z.object({
    title: z.string().min(1).max(300).transform(sanitizeHtml),
    content: z.string().min(1).max(20000).transform(sanitizeHtml),
    category: z.enum(forumCategories),
})

// ── Messages ─────────────────────────────────────────────────────────────

export const sendMessageSchema = z.object({
    recipientId: z.string().min(1),
    content: z.string().min(1).max(5000).transform(sanitizeHtml),
})

// ── Search ───────────────────────────────────────────────────────────────

export const searchSchema = z.object({
    q: z.string().min(2).max(500),
    category: z.string().optional(),
    model: z.string().optional(),
    semantic: z.coerce.boolean().optional(),
    limit: z.coerce.number().int().min(1).max(100).optional().default(20),
    offset: z.coerce.number().int().min(0).optional().default(0),
})

// ── Run ──────────────────────────────────────────────────────────────────

export const runSchema = z.object({
    prompt: z.string().min(1).max(100000),
    promptId: z.string().optional(),
    model: z.string().max(100).optional(),
    variables: z.record(z.string(), z.unknown()).optional(),
    turnstileToken: z.string().optional(),
    ollamaUrl: z.string().url().optional(),
})

// ── Workflows ────────────────────────────────────────────────────────────

export const createWorkflowSchema = z.object({
    name: z.string().min(1).max(200).transform(sanitizeHtml),
    description: sanitizedText(2000).optional(),
    steps: z.array(z.record(z.string(), z.unknown())).min(1),
    variables: z.record(z.string(), z.unknown()).optional(),
    visibility: z.enum(["public", "unlisted", "private"]).optional(),
})

// ── Utility: safe parse helper ───────────────────────────────────────────

import { NextResponse } from "next/server"

/**
 * Parse request body with a Zod schema, returning a typed NextResponse error on failure.
 */
export function parseBody<T extends z.ZodType>(
    schema: T,
    data: unknown
): { success: true; data: z.infer<T> } | { success: false; response: NextResponse } {
    const result = schema.safeParse(data)
    if (!result.success) {
        return {
            success: false,
            response: NextResponse.json(
                {
                    error: "Validation failed",
                    details: result.error.issues.map((i) => ({
                        path: i.path.join("."),
                        message: i.message,
                    })),
                },
                { status: 400 }
            ),
        }
    }
    return { success: true, data: result.data }
}

/**
 * Parse URL search params with a Zod schema.
 */
export function parseSearchParams<T extends z.ZodType>(
    schema: T,
    searchParams: URLSearchParams
): { success: true; data: z.infer<T> } | { success: false; response: NextResponse } {
    const obj: Record<string, string> = {}
    searchParams.forEach((value, key) => {
        obj[key] = value
    })
    return parseBody(schema, obj)
}