import http, { IncomingMessage } from 'http'
import fs from 'fs'
import path from 'path'
import crypto from 'node:crypto'
import { fileURLToPath } from 'url'
// import Docker from 'dockerode'
import cron from 'node-cron'
import loginUser, { getUser } from './helpers/resolve-user'
import { authCall, callNewChat, ollamaInp, schedInp } from './helpers/ollamaCalls'

const DEFAULT_TZ = "America/New_York"

const openApiSpec = {
	openapi: '3.0.1',
	info: {
		title: 'Scheduler API',
		description: 'API for managing scheduled prompts. Cron expressions run in America/New_York (EST).',
		version: '1.0.0'
	},
	servers: [
		{
			url: '/',
			description: 'Current server'
		}
	],
	paths: {
		'/api/schedules': {
			get: {
				summary: 'List schedules',
				security: [{ BearerAuth: [] }],
				responses: {
					200: {
						description: 'Successful response',
						content: {
							'application/json': {
								schema: {
									type: 'object',
									properties: {
										ok: { type: 'boolean', example: true },
										items: {
											type: 'array',
											items: { $ref: '#/components/schemas/Schedule' }
										}
									}
								}
							}
						}
					},
					401: { $ref: '#/components/responses/Unauthorized' }
				}
			},
				post: {
					summary: 'Create or replace a schedule',
					security: [{ BearerAuth: [] }],
				requestBody: {
					required: true,
					content: {
						'application/json': {
							schema: { $ref: '#/components/schemas/ScheduleInput' }
						}
					}
				},
				responses: {
					201: {
						description: 'Schedule created or updated',
						content: {
							'application/json': {
								schema: {
									type: 'object',
									properties: {
										ok: { type: 'boolean', example: true }
									}
								}
							}
						}
					},
					400: { $ref: '#/components/responses/BadRequest' },
					401: { $ref: '#/components/responses/Unauthorized' }
				}
			}
		},
		'/api/schedules/{name}': {
			delete: {
				summary: 'Delete a schedule',
				security: [{ BearerAuth: [] }],
				parameters: [
					{
						name: 'name',
						in: 'path',
						description: 'Schedule name (raw or scoped)',
						required: true,
						schema: { type: 'string' }
					}
				],
				responses: {
					204: { description: 'Schedule deleted' },
					401: { $ref: '#/components/responses/Unauthorized' },
					403: { $ref: '#/components/responses/Forbidden' },
					404: { $ref: '#/components/responses/NotFound' }
				}
			}
		}
	},
	components: {
		securitySchemes: {
			BearerAuth: {
				type: 'http',
				scheme: 'bearer',
				bearerFormat: 'JWT'
			}
		},
		schemas: {
			Schedule: {
				type: 'object',
				properties: {
					name: { type: 'string', description: 'Scoped identifier used internally' },
					displayName: { type: 'string' },
					userId: { type: 'string' },
					schedules: {
						type: 'array',
						items: { type: 'string', description: 'Cron expression' }
					},
					startAt: { type: 'string', format: 'date-time', nullable: true },
					oneShot: { type: 'boolean' },
					templateRef: { $ref: '#/components/schemas/TemplateRef' },
					prompt: { type: 'string' },
						model: { type: 'string' },
						tools: { type: 'array', items: { type: 'string' } },
						features: {
							type: 'object',
							additionalProperties: { type: 'boolean' }
						},
						files: {
							type: 'array',
							items: {
								type: 'object',
								properties: {
									fname: { type: 'string' },
									fkey: { type: 'string' }
								}
							}
						}
					},
					required: ['name', 'userId', 'schedules', 'oneShot']
			},
			ScheduleInput: {
				type: 'object',
				properties: {
					name: { type: 'string' },
					when: { $ref: '#/components/schemas/ScheduleWhen' },
					oneShot: { type: 'boolean', default: false },
					template: { $ref: '#/components/schemas/TemplateInput' },
					parameters: {
						type: 'object',
						additionalProperties: true
					},
					files: {
						type: 'array',
						items: {
							type: 'object',
							properties: {
								fname: { type: 'string' },
								fkey: {
									type: 'string',
									description: 'Optional previously stored file reference'
								},
								content: {
									type: 'string',
									description: 'Base64 encoded file contents'
								}
							},
							required: ['fname']
						}
					},
					prompt: { type: 'string' },
					model: { type: 'string' },
					tools: { type: 'array', items: { type: 'string' } },
					features: {
						type: 'object',
						additionalProperties: { type: 'boolean' }
					}
				},
				required: ['name', 'when', 'template', 'parameters', 'prompt', 'model', 'tools']
			},
			ScheduleWhen: {
				type: 'object',
				properties: {
					cron: {
						type: 'string',
						description: '5-field cron expression evaluated in America/New_York'
					},
					start: {
						type: 'string',
						format: 'date-time',
						description: 'Optional start gate; required when oneShot is true'
					}
				},
				required: []
			},
			TemplateInput: {
				type: 'object',
				properties: {
					name: { type: 'string' },
					clusterScope: { type: 'boolean', default: false }
				},
				required: ['name']
			},
			TemplateRef: {
				type: 'object',
				properties: {
					name: { type: 'string' },
					clusterScope: { type: 'boolean' }
				},
				required: ['name']
			}
		},
		responses: {
			Unauthorized: {
				description: 'Missing or invalid credentials'
			},
			BadRequest: {
				description: 'Invalid request payload',
				content: {
					'application/json': {
						schema: {
							type: 'object',
							properties: {
								ok: { type: 'boolean', example: false },
								error: { type: 'string' }
							}
						}
					}
				}
			},
			Forbidden: {
				description: 'Schedule exists but belongs to another user'
			},
			NotFound: {
				description: 'Schedule not found'
			}
		}
	}
} as const;

const __filename = fileURLToPath(import.meta.url),
	__dirname = path.dirname(__filename),

	// folders/files
	DATA_DIR = process.env.DATA_DIR || path.join(__dirname, 'data'),
	SCHEDULES_FILE = path.join(DATA_DIR, 'schedules.json'),
	TEMPLATES_FILE = process.env.TEMPLATES_FILE || path.join(__dirname, 'templates.json'),
	FILES_DIR_PREFERRED = process.env.FILES_DIR || '/app/data/files',
	FILES_DIR_FALLBACK = path.join(DATA_DIR, 'files');

let FILES_DIR = FILES_DIR_PREFERRED;

	// defaults
	PORT = Number(process.env.PORT) || 12253

// connect to docker (via local socket by default)
// const docker = new Docker({ socketPath: process.env.DOCKER_SOCKET || '/var/run/docker.sock' })

// in-memory schedule registry
const tasks = new Map() // key -> { task, def }

export const readBodyJson = (req: http.IncomingMessage): Promise<any> => new Promise((resolve, reject) => {
	let d = ''; req.on('data', c => d += c)
	req.on('end', () => { try { resolve(JSON.parse(d || '{}')) } catch (e) { reject(e) } })
	req.on('error', reject)
});

const ensureDir = (p: string) => { try { fs.mkdirSync(p, { recursive: true }) } catch { } },
	readJsonFile = (p: string, fallback: any = null) => { try { return JSON.parse(fs.readFileSync(p, 'utf8')) } catch { return fallback } },
	writeJsonFile = (p: string, obj: object) => fs.writeFileSync(p, JSON.stringify(obj, null, 2))

// build cron string from an iso timestamp (treated as America/New_York)
const cronFromISO = (iso?: string) => {
	if (!iso) return;
	const dt = new Date(iso);
	if (Number.isNaN(dt.getTime())) return;
	const parts: { year: number, month: number, day: number, hour: number, minute: number } = new Intl.DateTimeFormat('en-US', {
		timeZone: DEFAULT_TZ, year: 'numeric', month: 'numeric', day: 'numeric',
		hour: 'numeric', minute: '2-digit', hour12: false
	}).formatToParts(dt).reduce((a, p) => (a[p.type] = Number(p.value), a), {} as any);

	return `${parts.minute} ${parts.hour} ${parts.day} ${parts.month} *`;
}

const normalizeFeatures = (value: unknown): Record<string, boolean> => {
	if (!value || typeof value !== 'object' || Array.isArray(value)) return {};
	return Object.fromEntries(Object.entries(value as Record<string, unknown>).map(([k, v]) => [k, Boolean(v)]));
};

type IncomingFile = { fname?: string, fkey?: string, content?: string };

const sanitizeBase64 = (raw?: string) => typeof raw === 'string' ? raw.replace(/^data:[^;]+;base64,/, '') : '';

const prepareIncomingFiles = (value: unknown): { fname: string, fkey: string }[] | string => {
	if (!value) return [];
	if (!Array.isArray(value)) return 'files must be an array';

	const saved: { fname: string, fkey: string }[] = [];
	for (const entry of value as IncomingFile[]) {
		if (!entry || typeof entry !== 'object') return 'invalid file entry';
		const fname = typeof entry.fname === 'string' ? entry.fname.trim() : '';
		if (!fname) return 'file entries require fname';

		if (entry.content && typeof entry.content === 'string') {
			const b64 = sanitizeBase64(entry.content);
			if (!b64) return `file ${fname} is missing content`;
			const fkey = crypto.randomUUID();
			const target = path.join(FILES_DIR, fkey);
			try {
				fs.writeFileSync(target, Buffer.from(b64, 'base64'));
			} catch (err) {
				console.error('failed to store file', fname, err);
				return `failed to store file ${fname}`;
			}
			saved.push({ fname, fkey });
			continue;
		}

		if (entry.fkey && typeof entry.fkey === 'string' && entry.fkey.trim()) {
			saved.push({ fname, fkey: entry.fkey.trim() });
			continue;
		}

		return `file ${fname} is missing content or fkey`;
	}

	return saved;
};

// derive a docker-safe, user-scoped name and preserve a human display name
const scopedName = (name: string, userId: string) => {
	const base = String(name).toLowerCase().replace(/[^a-z0-9-]+/g, '-').replace(/^-+|-+$/g, '').slice(0, 40),
		suffix = String(userId).toLowerCase().replace(/[^a-z0-9]+/g, '').slice(0, 8) || 'anon';

	return `${base}--u-${suffix}`;
}

const fetchUserID = async (req: IncomingMessage) => {
	const authheader = String(req.headers['authorization'] || '').trim();
	if (!authheader) throw Object.assign(new Error('Missing authorization header'), { status: 401 });
	if (!authheader.startsWith('Bearer')) throw Object.assign(new Error('Invalid token'), { status: 401 });

	try {
		const token = authheader.split(' ')[1],
			user = await authCall(token);
		return user.id;
	}
	catch {
		throw Object.assign(new Error('Invalid token'), { status: 401 });
	}
}

// load templates (maps "name" -> { image, command?, args?, env? })
const loadTemplates = () => readJsonFile(TEMPLATES_FILE, { items: [] }).items || [];

// persistence of schedules (for restart durability)
ensureDir(DATA_DIR)
ensureDir(FILES_DIR)
if (!fs.existsSync(FILES_DIR)) {
	FILES_DIR = FILES_DIR_FALLBACK;
	ensureDir(FILES_DIR);
}
const persist = () => {
	const defs = [...tasks.values()].map(v => v.def)
	writeJsonFile(SCHEDULES_FILE, { items: defs })
};

const restore = () => {
	const saved = readJsonFile(SCHEDULES_FILE, { items: [] }).items || [];
	for (const def of saved) scheduleOrReplace(def);
};

// schedule management (create/update)
function scheduleOrReplace(defInput: ollamaInp) {
	const def: ollamaInp = { ...defInput, features: normalizeFeatures(defInput?.features) };

	// stop existing
	const key = def.name
	if (tasks.has(key)) { try { tasks.get(key).task.stop() } catch { } tasks.delete(key) }

    const startTs = def.startAt ? new Date(def.startAt).getTime() : null;

	// forbid overlapping runs per schedule (like argo's Forbid)
	let running = false
	const task = cron.schedule(def.schedule, async () => {
		if (running) return;
		if (startTs && Date.now() < startTs) return;

		running = true
		try {
			await callNewChat(def);

			// one-shot: stop after first success
			if (def.oneShot) {
				try { task.stop() } catch { }
				tasks.delete(key)
				persist()
			}
		} catch (err) {
			// TODO: collect errors here
			console.error(err);

			// this failed, stop the task now
			try { task.stop() } catch { }
			try { tasks.delete(key) } catch { }
			persist()
		} finally {
			running = false
		}
	}, { timezone: DEFAULT_TZ })

	tasks.set(key, { task, def })
	task.start()
	persist()
}

// also does validation
const toScheduleDef = ({ name, when, oneShot = false, template = { name: '' }, parameters = {}, prompt, userId, model, tools, features = {}, files = [] }: schedInp): ollamaInp | string => {
	const normalizedFeatures = normalizeFeatures(features);
	const startAt = when.start?.trim() || '';
	const hasStartAt = Boolean(startAt);
	const processedFiles = prepareIncomingFiles(files);
	if (typeof processedFiles === 'string') return processedFiles;

	if (oneShot) {
		if (!hasStartAt) return "One-shot schedules require a start date";
		const schedule = cronFromISO(startAt);
		if (!schedule) return "Invalid start date";
		const startDate = new Date(startAt);
		if (startDate.getTime() < Date.now()) return "Date can not be in the past";
		return {
			name: scopedName(name, userId),
			displayName: name,
			userId,
			schedule,
			startAt,
			oneShot: true,
			template,
			parameters,
			prompt,
			model,
			tools,
			features: normalizedFeatures,
			cookie: '',
			files: processedFiles
		};
	}

	const schedule = when.cron?.trim();
	if (!schedule) return "Cron expression is required";

	if (hasStartAt) {
		const startDate = new Date(startAt);
		if (Number.isNaN(startDate.getTime())) return "Invalid start date";
		if (startDate.getTime() < Date.now()) return "Start date can not be in the past";
	}

	return {
		name: scopedName(name, userId),
		displayName: name,
		userId,
		schedule,
		startAt: hasStartAt ? startAt : undefined,
		oneShot: false,
		template,
		parameters,
		prompt,
		model,
		tools,
		features: normalizedFeatures,
		cookie: '',
		files: processedFiles
	};
}

const publicDir = path.join(__dirname, 'public');

function reqToURL(req: IncomingMessage) {
	let pathname = '/';
	try {
		pathname = new URL(req.url!, `http://${req.headers.host || 'localhost'}`).pathname;
	} catch {
		pathname = req.url || '/';
	}

	return pathname;
}

// http server
const server = http.createServer(async (req, res) => {
	try {
		// very light cors
		const origin = req.headers.origin || '*'
		res.setHeader('access-control-allow-origin', origin)
		res.setHeader('vary', 'origin')
		res.setHeader('access-control-allow-headers', 'content-type, x-user-id')
		res.setHeader('access-control-allow-methods', 'GET, POST, DELETE, OPTIONS')
		if (req.method === 'OPTIONS') return res.writeHead(204).end()

		const pathname = reqToURL(req),
			allowed = ['/', ...fs.readdirSync(publicDir).map(f => `/${f}`)];

		if (req.method === 'GET' && pathname === '/openapi.json') {
			return res.writeHead(200, { 'content-type': 'application/json' }).end(JSON.stringify(openApiSpec, null, 2));
		}

		// list schedules for the calling user
		if (req.method === 'GET' && pathname === '/api/schedules') {
			const userId = await fetchUserID(req),
				items = [...tasks.values()]
					.map(v => v.def)
					.filter(d => d.userId === userId)
					.map(d => ({
						name: d.name,
						displayName: d.displayName,
						userId: d.userId,
						schedules: [d.schedule],
						startAt: d.startAt,
						oneShot: d.oneShot,
						templateRef: d.template,
						prompt: d.prompt,
						model: d.model,
						tools: d.tools,
						features: d.features,
						files: d.files
					}));

			return res.writeHead(200, { 'content-type': 'application/json' }).end(JSON.stringify({ ok: true, items }))
		}

		// list "workflow templates" => just expose templates.json names
		if (req.method === 'GET' && pathname === '/api/workflowtemplates') {
			const items = loadTemplates().map((t: { name: string }) => ({ name: t.name }))
			return res.writeHead(200, { 'content-type': 'application/json' }).end(JSON.stringify({ ok: true, items }))
		}

		if (req.method === 'GET' && allowed.includes(pathname)) {
			try {
				const fileName = pathname === '/' ? 'index.html' : pathname.slice(1),
					filePath = path.join(publicDir, fileName),
					ext = path.extname(fileName).toLowerCase(),
					type = ext === '.js' ? 'application/javascript' : ext === '.css' ? 'text/css' : 'text/html; charset=utf-8',
					content = fs.readFileSync(filePath, 'utf8')
				return res.writeHead(200, { 'content-type': type }).end(content);
			} catch {
				return res.writeHead(404).end('ui not found');
			}
		}


		// create/update a user-scoped schedule
		if (req.method === 'POST' && pathname === '/api/schedules') {
			const userId = await fetchUserID(req),
				input = await readBodyJson(req),
				def = toScheduleDef({ ...input, userId });

			if (typeof def === 'string') {
				return res.writeHead(400, { 'content-type': 'application/json' })
					.end(JSON.stringify({ error: def, ok: false }));
			}

			def.cookie = req.headers['authorization'].split(' ')[1];
			scheduleOrReplace(def);
			return res.writeHead(201, { 'content-type': 'application/json' }).end(JSON.stringify({ ok: true }));
		}

		if (req.method === 'POST' && pathname.startsWith('/login')) {
			return await loginUser(req, res).catch((err) => {
				console.error(err);
				res.writeHead(500).end();
			});
		}

		if (req.method === 'GET' && pathname.startsWith('/api/me')) {
			return await getUser(req, res).catch((err) => {
				console.error(err);
				res.writeHead(500).end();
			});
		}

		// delete a schedule owned by the calling user
		if (req.method === 'DELETE' && pathname.startsWith('/api/schedules/')) {
			const paramRaw = pathname.split('/').pop();
			if (!paramRaw) {
				return res.writeHead(400).end({ error: "missing schedule ID" });
			}

			const userId = await fetchUserID(req),
				nameParam = decodeURIComponent(paramRaw),
				// stored names are already scoped; accept either raw or scoped
				key = tasks.has(nameParam) ? nameParam : scopedName(nameParam, userId),
				existing = tasks.get(key)?.def;

			if (!existing) {
				return res.writeHead(404, {
					'content-type': 'application/json'
				}).end(JSON.stringify({
					ok: false,
					error: 'not found'
				}));
			}

			if (existing.userId !== userId) {
				return res.writeHead(403, {
					'content-type': 'application/json'
				}).end(JSON.stringify({
					ok: false,
					error: 'forbidden: schedule not owned by this user'
				}));
			}

			try { tasks.get(key).task.stop(); } catch { }
			tasks.delete(key);
			persist();

			return res.writeHead(204).end();
		}

		res.writeHead(404).end('not found');
	} catch (e: any) {
		console.error(e);
		const code = Number(e.status) || 500
		res.writeHead(code, { 'content-type': 'application/json' }).end(JSON.stringify({ ok: false, error: e.message || String(e) }))
	}
})

// boot
restore();
server.listen(PORT, "0.0.0.0", () => {
	const addr = server!.address();
	console.log(`schedules api listening on ${typeof addr === 'string' ? addr : addr?.address}:${PORT}`)
});