import { describe, expect, test } from "bun:test"
import { toBytecode, run } from "#reef"

describe("Programmatic Bytecode API", () => {
  test("basic stack operations", async () => {
    const bytecode = toBytecode([
      ["PUSH", 42],
      ["DUP"],
      ["POP"],
      ["HALT"]
    ])

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

  test("arithmetic operations", async () => {
    const bytecode = toBytecode([
      ["PUSH", 5],
      ["PUSH", 10],
      ["ADD"],
      ["HALT"]
    ])

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

  test("variables", async () => {
    const bytecode = toBytecode([
      ["PUSH", 100],
      ["STORE", "x"],
      ["LOAD", "x"],
      ["PUSH", 50],
      ["SUB"],
      ["HALT"]
    ])

    const result = await run(bytecode)
    expect(result).toEqual({ type: "number", value: 50 })
  })

  test("labels and jumps", async () => {
    const bytecode = toBytecode([
      ["PUSH", 5],
      ["PUSH", 10],
      ["GT"],
      ["JUMP_IF_TRUE", ".skip"],
      ["PUSH", 999],
      [".skip:"],
      ["PUSH", 42],
      ["HALT"]
    ])

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

  test("loop with labels", async () => {
    const bytecode = toBytecode([
      ["PUSH", 0],
      ["STORE", "i"],
      [".loop:"],
      ["LOAD", "i"],
      ["PUSH", 3],
      ["LT"],
      ["JUMP_IF_FALSE", ".end"],
      ["LOAD", "i"],
      ["PUSH", 1],
      ["ADD"],
      ["STORE", "i"],
      ["JUMP", ".loop"],
      [".end:"],
      ["LOAD", "i"],
      ["HALT"]
    ])

    const result = await run(bytecode)
    expect(result).toEqual({ type: "number", value: 3 })
  })

  test("simple function", async () => {
    const bytecode = toBytecode([
      ["MAKE_FUNCTION", ["x", "y"], ".add_body"],
      ["STORE", "add"],
      ["JUMP", ".after_fn"],
      [".add_body:"],
      ["LOAD", "x"],
      ["LOAD", "y"],
      ["ADD"],
      ["RETURN"],
      [".after_fn:"],
      ["LOAD", "add"],
      ["PUSH", 5],
      ["PUSH", 10],
      ["PUSH", 2],
      ["PUSH", 0],
      ["CALL"],
      ["HALT"]
    ])

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

  test("function with defaults", async () => {
    const bytecode = toBytecode([
      ["MAKE_FUNCTION", ["x", "y=10"], ".fn_body"],
      ["STORE", "fn"],
      ["JUMP", ".after"],
      [".fn_body:"],
      ["LOAD", "x"],
      ["LOAD", "y"],
      ["ADD"],
      ["RETURN"],
      [".after:"],
      ["LOAD", "fn"],
      ["PUSH", 5],
      ["PUSH", 1],
      ["PUSH", 0],
      ["CALL"],
      ["HALT"]
    ])

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

  test("variadic function", async () => {
    const bytecode = toBytecode([
      ["MAKE_FUNCTION", ["...args"], ".sum_body"],
      ["STORE", "sum"],
      ["JUMP", ".after"],
      [".sum_body:"],
      ["PUSH", 0],
      ["STORE", "total"],
      ["LOAD", "args"],
      ["ARRAY_LEN"],
      ["STORE", "len"],
      ["PUSH", 0],
      ["STORE", "i"],
      [".loop:"],
      ["LOAD", "i"],
      ["LOAD", "len"],
      ["LT"],
      ["JUMP_IF_FALSE", ".done"],
      ["LOAD", "total"],
      ["LOAD", "args"],
      ["LOAD", "i"],
      ["ARRAY_GET"],
      ["ADD"],
      ["STORE", "total"],
      ["LOAD", "i"],
      ["PUSH", 1],
      ["ADD"],
      ["STORE", "i"],
      ["JUMP", ".loop"],
      [".done:"],
      ["LOAD", "total"],
      ["RETURN"],
      [".after:"],
      ["LOAD", "sum"],
      ["PUSH", 1],
      ["PUSH", 2],
      ["PUSH", 3],
      ["PUSH", 3],
      ["PUSH", 0],
      ["CALL"],
      ["HALT"]
    ])

    const result = await run(bytecode)
    expect(result).toEqual({ type: "number", value: 6 })
  })

  test("named parameters", async () => {
    const bytecode = toBytecode([
      ["MAKE_FUNCTION", ["x", "@opts"], ".fn_body"],
      ["STORE", "fn"],
      ["JUMP", ".after"],
      [".fn_body:"],
      ["LOAD", "x"],
      ["RETURN"],
      [".after:"],
      ["LOAD", "fn"],
      ["PUSH", 42],
      ["PUSH", "verbose"],
      ["PUSH", true],
      ["PUSH", 1],
      ["PUSH", 1],
      ["CALL"],
      ["HALT"]
    ])

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

  test("arrays", async () => {
    const bytecode = toBytecode([
      ["PUSH", 1],
      ["PUSH", 2],
      ["PUSH", 3],
      ["MAKE_ARRAY", 3],
      ["HALT"]
    ])

    const result = await run(bytecode)
    expect(result.type).toBe("array")
    if (result.type === "array") {
      expect(result.value).toHaveLength(3)
    }
  })

  test("dicts", async () => {
    const bytecode = toBytecode([
      ["PUSH", "name"],
      ["PUSH", "Alice"],
      ["PUSH", "age"],
      ["PUSH", 30],
      ["MAKE_DICT", 2],
      ["HALT"]
    ])

    const result = await run(bytecode)
    expect(result.type).toBe("dict")
  })

  test("exception handling", async () => {
    const bytecode = toBytecode([
      ["PUSH_TRY", ".catch"],
      ["PUSH", "error!"],
      ["THROW"],
      ["POP_TRY"],
      [".catch:"],
      ["STORE", "err"],
      ["LOAD", "err"],
      ["HALT"]
    ])

    const result = await run(bytecode)
    expect(result).toEqual({ type: "string", value: "error!" })
  })

  test("string values", async () => {
    const bytecode = toBytecode([
      ["PUSH", "hello"],
      ["HALT"]
    ])

    const result = await run(bytecode)
    expect(result).toEqual({ type: "string", value: "hello" })
  })

  test("boolean values", async () => {
    const bytecode = toBytecode([
      ["PUSH", true],
      ["NOT"],
      ["HALT"]
    ])

    const result = await run(bytecode)
    expect(result).toEqual({ type: "boolean", value: false })
  })

  test("null values", async () => {
    const bytecode = toBytecode([
      ["PUSH", null],
      ["HALT"]
    ])

    const result = await run(bytecode)
    expect(result).toEqual({ type: "null", value: null })
  })

  test("tail call", async () => {
    const bytecode = toBytecode([
      ["MAKE_FUNCTION", ["n", "acc"], ".factorial_body"],
      ["STORE", "factorial"],
      ["JUMP", ".main"],
      [".factorial_body:"],
      ["LOAD", "n"],
      ["PUSH", 0],
      ["LTE"],
      ["JUMP_IF_FALSE", ".recurse"],
      ["LOAD", "acc"],
      ["RETURN"],
      [".recurse:"],
      ["LOAD", "factorial"],
      ["LOAD", "n"],
      ["PUSH", 1],
      ["SUB"],
      ["LOAD", "n"],
      ["LOAD", "acc"],
      ["MUL"],
      ["PUSH", 2],
      ["PUSH", 0],
      ["TAIL_CALL"],
      [".main:"],
      ["LOAD", "factorial"],
      ["PUSH", 5],
      ["PUSH", 1],
      ["PUSH", 2],
      ["PUSH", 0],
      ["CALL"],
      ["HALT"]
    ])

    const result = await run(bytecode)
    expect(result).toEqual({ type: "number", value: 120 })
  })
})