import { test, expect } from "bun:test"
import { VM } from "#vm"
import { toBytecode } from "#bytecode"
import { toValue, toNumber, toString } from "#value"

test("CALL_NATIVE - basic function call", async () => {
  const bytecode = toBytecode(`
    PUSH 5
    PUSH 10
    CALL_NATIVE add
  `)

  const vm = new VM(bytecode)

  // Register a Value-based function
  vm.registerValueFunction('add', (a, b) => {
    return toValue(toNumber(a) + toNumber(b))
  })

  const result = await vm.run()
  expect(result).toEqual({ type: 'number', value: 15 })
})

test("CALL_NATIVE - function with string manipulation", async () => {
  const bytecode = toBytecode(`
    PUSH "hello"
    PUSH "world"
    CALL_NATIVE concat
  `)

  const vm = new VM(bytecode)

  vm.registerValueFunction('concat', (a, b) => {
    const aStr = a.type === 'string' ? a.value : toString(a)
    const bStr = b.type === 'string' ? b.value : toString(b)
    return toValue(aStr + ' ' + bStr)
  })

  const result = await vm.run()
  expect(result).toEqual({ type: 'string', value: 'hello world' })
})

test("CALL_NATIVE - async function", async () => {
  const bytecode = toBytecode(`
    PUSH 42
    CALL_NATIVE asyncDouble
  `)

  const vm = new VM(bytecode)

  vm.registerValueFunction('asyncDouble', async (a) => {
    // Simulate async operation
    await new Promise(resolve => setTimeout(resolve, 1))
    return toValue(toNumber(a) * 2)
  })

  const result = await vm.run()
  expect(result).toEqual({ type: 'number', value: 84 })
})

test("CALL_NATIVE - function with no arguments", async () => {
  const bytecode = toBytecode(`
    CALL_NATIVE getAnswer
  `)

  const vm = new VM(bytecode)

  vm.registerValueFunction('getAnswer', () => {
    return toValue(42)
  })

  const result = await vm.run()
  expect(result).toEqual({ type: 'number', value: 42 })
})

test("CALL_NATIVE - function with multiple arguments", async () => {
  const bytecode = toBytecode(`
    PUSH 2
    PUSH 3
    PUSH 4
    CALL_NATIVE sum
  `)

  const vm = new VM(bytecode)

  vm.registerValueFunction('sum', (...args) => {
    const total = args.reduce((acc, val) => acc + toNumber(val), 0)
    return toValue(total)
  })

  const result = await vm.run()
  expect(result).toEqual({ type: 'number', value: 9 })
})

test("CALL_NATIVE - function returns array", async () => {
  const bytecode = toBytecode(`
    PUSH 3
    CALL_NATIVE makeRange
  `)

  const vm = new VM(bytecode)

  vm.registerValueFunction('makeRange', (n) => {
    const count = toNumber(n)
    const arr = []
    for (let i = 0; i < count; i++) {
      arr.push(toValue(i))
    }
    return { type: 'array', value: arr }
  })

  const result = await vm.run()
  expect(result.type).toBe('array')
  if (result.type === 'array') {
    expect(result.value.length).toBe(3)
    expect(result.value).toEqual([
      toValue(0),
      toValue(1),
      toValue(2)
    ])
  }
})

test("CALL_NATIVE - function not found", async () => {
  const bytecode = toBytecode(`
    CALL_NATIVE nonexistent
  `)

  const vm = new VM(bytecode)

  await expect(vm.run()).rejects.toThrow('CALL_NATIVE: function not found: nonexistent')
})

test("CALL_NATIVE - using result in subsequent operations", async () => {
  const bytecode = toBytecode(`
    PUSH 5
    CALL_NATIVE triple
    PUSH 10
    ADD
  `)

  const vm = new VM(bytecode)

  vm.registerValueFunction('triple', (n) => {
    return toValue(toNumber(n) * 3)
  })

  const result = await vm.run()
  expect(result).toEqual({ type: 'number', value: 25 })
})

test("Native function wrapping - basic sync function with native types", async () => {
  const bytecode = toBytecode(`
    PUSH 5
    PUSH 10
    CALL_NATIVE add
  `)

  const vm = new VM(bytecode)

  // Register with native TypeScript types - auto-wraps!
  vm.registerFunction('add', (a: number, b: number) => {
    return a + b
  })

  const result = await vm.run()
  expect(result).toEqual({ type: 'number', value: 15 })
})

test("Native function wrapping - async function with native types", async () => {
  const bytecode = toBytecode(`
    PUSH 42
    CALL_NATIVE asyncDouble
  `)

  const vm = new VM(bytecode)

  // Async native function
  vm.registerFunction('asyncDouble', async (n: number) => {
    await new Promise(resolve => setTimeout(resolve, 1))
    return n * 2
  })

  const result = await vm.run()
  expect(result).toEqual({ type: 'number', value: 84 })
})

test("Native function wrapping - string manipulation", async () => {
  const bytecode = toBytecode(`
    PUSH "hello"
    PUSH "world"
    CALL_NATIVE concat
  `)

  const vm = new VM(bytecode)

  // Native string function
  vm.registerFunction('concat', (a: string, b: string) => {
    return a + ' ' + b
  })

  const result = await vm.run()
  expect(result).toEqual({ type: 'string', value: 'hello world' })
})

test("Native function wrapping - with default parameters", async () => {
  const bytecode = toBytecode(`
    PUSH "/home/user"
    CALL_NATIVE ls
  `)

  const vm = new VM(bytecode)

  // Function with default parameter (like NOSE commands)
  vm.registerFunction('ls', (path: string, link = false) => {
    return link ? `listing ${path} with links` : `listing ${path}`
  })

  const result = await vm.run()
  expect(result).toEqual({ type: 'string', value: 'listing /home/user' })
})

test("Native function wrapping - returns array", async () => {
  const bytecode = toBytecode(`
    PUSH 3
    CALL_NATIVE makeRange
  `)

  const vm = new VM(bytecode)

  // Return native array - auto-converts to Value array
  vm.registerFunction('makeRange', (n: number) => {
    return Array.from({ length: n }, (_, i) => i)
  })

  const result = await vm.run()
  expect(result.type).toBe('array')
  if (result.type === 'array') {
    expect(result.value.length).toBe(3)
    expect(result.value).toEqual([
      toValue(0),
      toValue(1),
      toValue(2)
    ])
  }
})

test("Native function wrapping - returns object (becomes dict)", async () => {
  const bytecode = toBytecode(`
    PUSH "Alice"
    PUSH 30
    CALL_NATIVE makeUser
  `)

  const vm = new VM(bytecode)

  // Return plain object - auto-converts to dict
  vm.registerFunction('makeUser', (name: string, age: number) => {
    return { name, age }
  })

  const result = await vm.run()
  expect(result.type).toBe('dict')
  if (result.type === 'dict') {
    expect(result.value.get('name')).toEqual(toValue('Alice'))
    expect(result.value.get('age')).toEqual(toValue(30))
  }
})

test("Native function wrapping - mixed with manual Value functions", async () => {
  const bytecode = toBytecode(`
    PUSH 5
    CALL_NATIVE nativeAdd
    CALL_NATIVE manualDouble
  `)

  const vm = new VM(bytecode)

  // Native function (auto-wrapped by registerFunction)
  vm.registerFunction('nativeAdd', (n: number) => n + 10)

  // Manual Value function (use registerValueFunction)
  vm.registerValueFunction('manualDouble', (v) => {
    return toValue(toNumber(v) * 2)
  })

  const result = await vm.run()
  expect(result).toEqual({ type: 'number', value: 30 })
})