import {evaluate} from '@marcbachmann/cel-js'

// Simple evaluation
evaluate('1 + 2 * 3') // 7n

// With context
const allowed = evaluate(
  'user.age >= 18 && "admin" in user.roles',
  {user: {age: 30, roles: ['admin', 'user']}}
)
// true

import {evaluate, parse} from '@marcbachmann/cel-js'

// Direct evaluation
evaluate('1 + 2') // 3n

// With variables
evaluate('name + "!"', {name: 'Alice'}) // "Alice!"

// Parse once, evaluate multiple times for better performance
const expr = parse('user.age >= minAge')
expr({user: {age: 25}, minAge: 18}) // true
expr({user: {age: 16}, minAge: 18}) // false

// Access parsed AST and type checking
console.log(expr.ast)        // AST representation
const typeCheck = expr.check() // Type check without evaluation

import {Environment} from '@marcbachmann/cel-js'
class User {
  constructor ({email, age}) {
    this.email = email
    this.age = age
  }
}

const env = new Environment()
  .registerType('User', {
    fields: {
      email: 'string',
      age: 'int'
    },
    ctor: User
  })
  .registerVariable('skipAgeCheck', 'bool')
  .registerVariable('user', 'User')
  .registerConstant('minAge', 'int', 18n)
  .registerFunction('isAdult(int): bool', age => age >= 18n)
  .registerOperator('string * int', (str, n) => str.repeat(Number(n)))

// Type-checked evaluation with constant
env.evaluate(
  'skipAgeCheck || (isAdult(user.age) && (user.age >= minAge))', {
  user: new User({age: 25n}),
  skipAgeCheck: true
})

// Custom operators
env.evaluate('"Hi" * 3') // "HiHiHi"

import {Environment} from '@marcbachmann/cel-js'

const env = new Environment()
  .registerConstant('minAge', 'int', 18n)

env.evaluate('user.age >= minAge', {user: {age: 20n}}) // true

env.registerConstant('minAge', 'int', 18n)
env.registerConstant({name: 'minAge', type: 'int', value: 18n, description: 'Minimum age'})

new Environment({
  // Treat undeclared variables as dynamic type
  unlistedVariablesAreDyn: false,
  // Require list/map literals to stay strictly homogeneous (default: true)
  homogeneousAggregateLiterals: true,
  // Enable .?key/.[?key] optional chaining and optional.* helpers (default: false)
  enableOptionalTypes: true,
  // Optional structural limits (parse time)
  limits: {
    maxAstNodes: 100000,
    maxDepth: 250,
    maxListElements: 1000,
    maxMapEntries: 1000,
    maxCallArguments: 32
  }
})

env.registerVariable('user', 'map')
env.registerVariable('user', 'map', {description: 'The current user'})
env.registerVariable('user', {type: 'map', description: 'The current user'})
env.registerVariable({name: 'user', type: 'map', description: 'The current user'})

// Passing a schema property will implicitly create a custom type and
// convert objects/maps to a new class instance. Those values then behave similar like
// explicit types that are created using a constructor.
env.registerVariable({
  name: 'user',
  schema: {
    email: 'string',
    age: 'int',
    profile: {
      tags: 'list<string>',
      avatar: 'string'
    }
  }
})

// Name + constructor class
// when fields are not provided, own properties are accessible automatically
env.registerType('Vector', Vector)

// Name + object with constructor and field types
env.registerType('Vector', {ctor: Vector, fields: {x: 'double', y: 'double'}})

// Name + object with fields only (auto-generates a wrapper class and convert function)
env.registerType('Vector', {fields: {x: 'double', y: 'double'}})

// Name + object with nested schema (registers nested types automatically)
// But this type can only be used during variable registration.
env.registerType('Vector', {schema: {x: 'double', y: 'double'}})

// Single object with name and schema
env.registerType({name: 'Vector', schema: {x: 'double', y: 'double'}})

// Single object with constructor (name inferred from constructor)
env.registerType({ctor: Vector, fields: {x: 'double', y: 'double'}})

// Signature string + handler
env.registerFunction('greet(string): string', (name) => `Hello, ${name}!`)
env.registerFunction('greet(string): string', handler, {description: 'Greets someone'})
env.registerFunction('greet(string): string', {handler, description: 'Greets someone'})

// Single object with signature string
env.registerFunction({signature: 'add(int, int): int', handler, description: 'Adds two integers'})

// Single object with signature string and named params
env.registerFunction({
  signature: 'formatDate(int, string): string',
  handler,
  description: 'Formats a timestamp',
  params: [
    {name: 'timestamp', description: 'Unix timestamp in seconds'},
    {name: 'format', description: 'Date format string'}
  ]
})

// Single object without signature string
env.registerFunction({
  name: 'multiply',
  returnType: 'int',
  handler: (a, b) => a * b,
  description: 'Multiplies two integers',
  params: [
    {name: 'a', type: 'int', description: 'First number'},
    {name: 'b', type: 'int', description: 'Second number'}
  ]
})

// Receiver method (called as 'hello'.shout())
env.registerFunction({
  name: 'shout',
  receiverType: 'string',
  returnType: 'string',
  handler: (str) => str.toUpperCase() + '!',
  params: []
})

const env = new Environment()
  .registerFunction('fetchUser(string): map', async (id) => {
    const res = await fetch(`/users/${id}`)
    return res.json()
  })

const user = await env.evaluate('fetchUser(userId)', {userId: '42'})

import assert from 'node:assert/strict'

const parent = new Environment().registerVariable('user', 'map')
const child = parent.clone()

// Parent registries is frozen once cloned
assert.throws(() => parent.registerVariable('foo', 'dyn'))

// Child stays fully extensible without deep-copy overhead
child
  .registerFunction('isAdult(map): bool', (u) => u.age >= 18n)
  .registerVariable('minAge', 'int')

child.evaluate('isAdult(user) && user.age >= minAge', {
  user: {age: 20n},
  minAge: 18n
})

import {Environment, TypeError} from '@marcbachmann/cel-js'

const env = new Environment()
  .registerVariable('age', 'int')
  .registerVariable('name', 'string')

// Check expression validity
const result = env.check('age >= 18 && name.startsWith("A")')

if (result.valid) {
  console.log(`Expression is valid, returns: ${result.type}`) // bool
  // Safe to evaluate
  const value = env.evaluate('age >= 18 && name.startsWith("A")', {
    age: 25n,
    name: 'Alice'
  })
} else {
  console.error(`Type error: ${result.error.message}`)
}

// Detect errors without evaluation
const invalid = env.check('age + name') // Invalid: can't add int + string
console.log(invalid.valid) // false
console.log(invalid.error.message) // "Operator '+' not defined for types 'int' and 'string'"

// Arithmetic
evaluate('10 + 5 - 3')     // 12n
evaluate('10 * 5 / 2')     // 25n
evaluate('10 % 3')         // 1n

// Comparison
evaluate('5 > 3')          // true
evaluate('5 >= 5')         // true
evaluate('5 == 5')         // true
evaluate('5 != 4')         // true

// Logical
evaluate('true && false')  // false
evaluate('true || false')  // true
evaluate('!false')         // true

// Ternary
evaluate('5 > 3 ? "yes" : "no"')  // "yes"

// Membership
evaluate('2 in [1, 2, 3]')        // true
evaluate('"ell" in "hello"')      // true

// Numbers (default to BigInt)
evaluate('42')           // 42n
evaluate('3.14')         // 3.14
evaluate('0xFF')         // 255n

// Strings
evaluate('"hello"')      // "hello"
evaluate('r"\\n"')       // "\\n" (raw string)
evaluate('"""multi\nline"""')  // "multi\nline\n"

// Bytes
evaluate('b"hello"')     // Uint8Array
evaluate('b"\\xFF"')     // Uint8Array [255]

// Collections
evaluate('[1, 2, 3]')           // [1n, 2n, 3n]
evaluate('{name: "Alice"}')     // {name: "Alice"}

// Other
evaluate('true')         // true
evaluate('null')         // null

// Type conversion
evaluate('string(123)')           // "123"
evaluate('int("42")')             // 42n
evaluate('double("3.14")')        // 3.14
evaluate('bytes("hello")')        // Uint8Array
evaluate('dyn(42)')               // Converts to dynamic type

// Collections
evaluate('size([1, 2, 3])')       // 3n
evaluate('size("hello")')         // 5n
evaluate('size({a: 1, b: 2})')    // 2n

// Time
evaluate('timestamp("2024-01-01T00:00:00Z")')  // Date

// Type checking
evaluate('type(42)')              // int
evaluate('type("hello")')         // string

evaluate('"hello".contains("ell")')         // true
evaluate('"hello".startsWith("he")')        // true
evaluate('"hello".endsWith("lo")')          // true
evaluate('"hello".matches("h.*o")')         // true
evaluate('"hello".size()')                  // 5n
evaluate('"hello".indexOf("ll")')           // 2n
evaluate('"hello world".indexOf("o", 5)')   // 7n (search from index 5)
evaluate('"hello".lastIndexOf("l")')        // 3n
evaluate('"hello".substring(1)')            // "ello"
evaluate('"hello".substring(1, 4)')         // "ell"

evaluate('[1, 2, 3].size()')                // 3n
evaluate('["a", "b", "c"].join()')          // "abc"
evaluate('["a", "b", "c"].join(", ")')      // "a, b, c"

evaluate('b"hello".size()')                 // 5n
evaluate('b"hello".string()')               // "hello"
evaluate('b"hello".hex()')                  // "68656c6c6f"
evaluate('b"hello".base64()')               // "aGVsbG8="
evaluate('b"{\\"x\\": 42}".json()')         // {x: 42n}
evaluate('b"hello".at(0)')                  // 104n (byte value at index)

const ctx = {t: new Date('2024-01-15T14:30:45.123Z')}

evaluate('t.getFullYear()', ctx)            // 2024n
evaluate('t.getMonth()', ctx)               // 0n (January, 0-indexed)
evaluate('t.getDayOfMonth()', ctx)          // 15n
evaluate('t.getDayOfWeek()', ctx)           // 1n (Monday, 0=Sunday)
evaluate('t.getDayOfYear()', ctx)           // 15n
evaluate('t.getHours()', ctx)               // 14n
evaluate('t.getMinutes()', ctx)             // 30n
evaluate('t.getSeconds()', ctx)             // 45n
evaluate('t.getMilliseconds()', ctx)        // 123n

// With timezone
evaluate('t.getHours("America/New_York")', ctx)  // 9n (UTC-5)

const ctx = {
  numbers: [1, 2, 3, 4, 5],
  users: [
    {name: 'Alice', admin: true},
    {name: 'Bob', admin: false}
  ]
}

// Check property exists
evaluate('has(user.email)', {user: {}})  // false

// All elements match
evaluate('numbers.all(n, n > 0)', ctx)   // true

// Any element matches
evaluate('numbers.exists(n, n > 3)', ctx)  // true

// Exactly one matches
evaluate('numbers.exists_one(n, n == 3)', ctx)  // true

// Transform
evaluate('numbers.map(n, n * 2)', ctx)
// [2n, 4n, 6n, 8n, 10n]

// Filter
evaluate('numbers.filter(n, n > 2)', ctx)
// [3n, 4n, 5n]

// Filter + Transform
evaluate('users.filter(u, u.admin).map(u, u.name)', ctx)

// Bind a temporary value within the expression
evaluate('cel.bind(total, users.map(u, u.admin, u.score).sum(), total >= 90)', ctx)

// Or using three arg form of .map
evaluate('users.map(u, u.admin, u.name)', ctx)
// ["Alice"]

import {Environment} from '@marcbachmann/cel-js'

const env = new Environment()
env.registerFunction('macro(ast): dyn', ({ast, args}) => {
  // Any parameter on this object are available as
  // the `macro` parameter within the `typeCheck` and `evaluate` functions below.
  return {
    // e.g. you can precompute values during parse time
    firstArgument: args[0],
    // Mandatory: called when the expression is type-checked
    typeCheck(checker, macro, ctx) {
      return checker.check(macro.firstArgument, ctx)
    },
    // Mandatory: called when the expression is evaluated
    evaluate(evaluator, macro, ctx) {
      return evaluator.eval(macro.firstArgument, ctx)
    }
  }
})

import {Environment} from '@marcbachmann/cel-js'

class Vector {
  constructor(x, y) {
    this.x = x
    this.y = y
  }
  add(other) {
    return new Vector(this.x + other.x, this.y + other.y)
  }
}

const env = new Environment()
  .registerType('Vector', Vector)
  .registerVariable('v1', 'Vector')
  .registerVariable('v2', 'Vector')
  .registerOperator('Vector + Vector', (a, b) => a.add(b))
  .registerFunction('magnitude(Vector): double', (v) =>
    Math.sqrt(v.x * v.x + v.y * v.y)
  )

const result = env.evaluate('magnitude(v1 + v2)', {
  v1: new Vector(3, 4),
  v2: new Vector(1, 2)
})
// 7.211102550927978

import {evaluate, ParseError, EvaluationError, TypeError} from '@marcbachmann/cel-js'

try {
  evaluate('invalid + + syntax')
} catch (error) {
  if (error instanceof ParseError) {
    console.error('Syntax error:', error.message)
  } else if (error instanceof EvaluationError) {
    console.error('Runtime error:', error.message)
  }
}

// Type checking returns errors without throwing
const env = new Environment().registerVariable('x', 'int')
const result = env.check('x + "string"')
if (!result.valid && result.error instanceof TypeError) {
  console.error('Type error:', result.error.message)
}

import {Environment} from '@marcbachmann/cel-js'

// Instantiating an environment is expensive, please do that outside hot code paths
const authEnv = new Environment()
  .registerVariable('user', 'map')
  .registerVariable('resource', 'map')

const canEdit = authEnv.parse(`
  user.isActive &&
  (user.role == "admin" ||
  user.id == resource.ownerId)
`)

canEdit({
  user: {id: 123, role: 'user', isActive: true},
  resource: {ownerId: 123}
}) // true

import {Environment} from '@marcbachmann/cel-js'

// Instantiating an environment is expensive, please do that outside hot code paths
const validator = new Environment()
  .registerVariable('email', 'string')
  .registerVariable('age', 'int')
  .registerFunction('isValidEmail(string): bool',
    email => /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email)
  )

const valid = validator.evaluate(
  'isValidEmail(email) && age >= 18 && age < 120',
  {email: 'user@example.com', age: 25n}
)

import {parse} from '@marcbachmann/cel-js'

const flags = {
  'new-dashboard': parse(
    'user.betaUser || user.id in allowedUserIds'
  ),
  'premium-features': parse(
    'user.subscription == "pro" && !user.trialExpired'
  )
}

function isEnabled(feature, context) {
  return flags[feature]?.(context) ?? false
}