import { test, expect } from "bun:test"
import { run } from "#index"
import { toBytecode } from "#bytecode"

test("ADD - add two numbers", async () => {
  const str = `
  PUSH 1
  PUSH 5
  ADD
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 6 })

  const str2 = `
  PUSH 100
  PUSH 500
  ADD
`
  expect(await run(toBytecode(str2))).toEqual({ type: 'number', value: 600 })
})

test("SUB - subtract two numbers", async () => {
  const str = `
  PUSH 5
  PUSH 2
  SUB
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 3 })
})

test("MUL - multiply two numbers", async () => {
  const str = `
  PUSH 5
  PUSH 2
  MUL
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 10 })
})

test("DIV - divide two numbers", async () => {
  const str = `
  PUSH 10
  PUSH 2
  DIV
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 5 })

  const str2 = `
  PUSH 10
  PUSH 0
  DIV
`
  expect(await run(toBytecode(str2))).toEqual({ type: 'number', value: Infinity })
})

test("MOD - modulo two numbers", async () => {
  const str = `
  PUSH 17
  PUSH 5
  MOD
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 2 })
})

test("PUSH - pushes value onto stack", async () => {
  const str = `
  PUSH 42
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 42 })
})

test("POP - removes top value", async () => {
  const str = `
  PUSH 10
  PUSH 20
  POP
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 10 })
})

test("DUP - duplicates top value", async () => {
  const str = `
  PUSH 5
  DUP
  ADD
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 10 })
})

test("EQ - equality comparison", async () => {
  const str = `
  PUSH 5
  PUSH 5
  EQ
`
  expect(await run(toBytecode(str))).toEqual({ type: 'boolean', value: true })

  const str2 = `
  PUSH 5
  PUSH 10
  EQ
`
  expect(await run(toBytecode(str2))).toEqual({ type: 'boolean', value: false })
})

test("NEQ - not equal comparison", async () => {
  const str = `
  PUSH 5
  PUSH 10
  NEQ
`
  expect(await run(toBytecode(str))).toEqual({ type: 'boolean', value: true })
})

test("LT - less than", async () => {
  const str = `
  PUSH 5
  PUSH 10
  LT
`
  expect(await run(toBytecode(str))).toEqual({ type: 'boolean', value: true })
})

test("GT - greater than", async () => {
  const str = `
  PUSH 10
  PUSH 5
  GT
`
  expect(await run(toBytecode(str))).toEqual({ type: 'boolean', value: true })
})

test("LTE - less than or equal", async () => {
  // equal case
  const str = `
  PUSH 5
  PUSH 5
  LTE
`
  expect(await run(toBytecode(str))).toEqual({ type: 'boolean', value: true })

  // less than case
  const str2 = `
  PUSH 3
  PUSH 5
  LTE
`
  expect(await run(toBytecode(str2))).toEqual({ type: 'boolean', value: true })

  // greater than case (false)
  const str3 = `
  PUSH 10
  PUSH 5
  LTE
`
  expect(await run(toBytecode(str3))).toEqual({ type: 'boolean', value: false })
})

test("GTE - greater than or equal", async () => {
  // equal case
  const str = `
  PUSH 5
  PUSH 5
  GTE
`
  expect(await run(toBytecode(str))).toEqual({ type: 'boolean', value: true })

  // greater than case
  const str2 = `
  PUSH 10
  PUSH 5
  GTE
`
  expect(await run(toBytecode(str2))).toEqual({ type: 'boolean', value: true })

  // less than case (false)
  const str3 = `
  PUSH 3
  PUSH 5
  GTE
`
  expect(await run(toBytecode(str3))).toEqual({ type: 'boolean', value: false })
})

test("AND pattern - short circuits when false", async () => {
  // false && <anything> should short-circuit and return false
  const str = `
  PUSH 1
  PUSH 0
  EQ
  DUP
  JUMP_IF_FALSE .end
  POP
  PUSH 999
  .end:
`
  const result = await run(toBytecode(str))
  expect(result.type).toBe('boolean')
  if (result.type === 'boolean') {
    expect(result.value).toBe(false)
  }
})

test("AND pattern - evaluates both when true", async () => {
  const str = `
  PUSH 1
  DUP
  JUMP_IF_FALSE .end
  POP
  PUSH 2
  .end:
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 2 })
})

test("OR pattern - short circuits when true", async () => {
  const str = `
  PUSH 1
  DUP
  JUMP_IF_TRUE .end
  POP
  PUSH 2
  .end:
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 1 })
})

test("OR pattern - evaluates second when false", async () => {
  const str = `
  PUSH 1
  PUSH 0
  EQ
  DUP
  JUMP_IF_TRUE .end
  POP
  PUSH 2
  .end:
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 2 })
})

test("NOT - logical not", async () => {
  // number is truthy, so NOT returns false
  const str = `
  PUSH 1
  NOT
`
  expect(await run(toBytecode(str))).toEqual({ type: 'boolean', value: false })

  // 0 is truthy in this language, so NOT returns false
  const str2 = `
  PUSH 0
  NOT
`
  expect(await run(toBytecode(str2))).toEqual({ type: 'boolean', value: false })

  // boolean false is falsy, so NOT returns true
  const str3 = `
  PUSH 1
  PUSH 0
  EQ
  NOT
`
  expect(await run(toBytecode(str3))).toEqual({ type: 'boolean', value: true })
})

test("isTruthy - only null and false are falsy", async () => {
  // 0 is truthy (unlike JS)
  const str1 = `
  PUSH 0
  JUMP_IF_FALSE .end
  PUSH 1
  .end:
`
  expect(await run(toBytecode(str1))).toEqual({ type: 'number', value: 1 })

  // empty string is truthy (unlike JS)
  const str2 = `
  PUSH ''
  JUMP_IF_FALSE .end
  PUSH 1
  .end:
`
  expect(await run(toBytecode(str2))).toEqual({ type: 'number', value: 1 })

  // false is falsy
  const str3 = `
  PUSH 0
  PUSH 0
  EQ
  JUMP_IF_FALSE .end
  PUSH 999
  .end:
`
  expect(await run(toBytecode(str3))).toEqual({ type: 'number', value: 999 })
})

test("HALT - stops execution", async () => {
  const str = `
  PUSH 42
  HALT
  PUSH 100
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 42 })
})

test("STORE and LOAD - variables", async () => {
  const str = `
  PUSH 42
  STORE x
  PUSH 21
  LOAD x
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 42 })
})

test("STORE and LOAD - multiple variables", async () => {
  const str = `
  PUSH 10
  STORE a
  PUSH 20
  STORE b
  PUSH 44
  LOAD a
  LOAD b
  ADD
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 30 })
})

test("TRY_LOAD - variable found", async () => {
  const str = `
  PUSH 100
  STORE count
  TRY_LOAD count
  `
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 100 })

  const str2 = `
  PUSH 'Bobby'
  STORE name
  TRY_LOAD name
  `
  expect(await run(toBytecode(str2))).toEqual({ type: 'string', value: 'Bobby' })
})

test("TRY_LOAD - variable missing", async () => {
  const str = `
  PUSH 100
  STORE count
  TRY_LOAD count1
  `
  expect(await run(toBytecode(str))).toEqual({ type: 'string', value: 'count1' })

  const str2 = `
  PUSH 'Bobby'
  STORE name
  TRY_LOAD full-name
  `
  expect(await run(toBytecode(str2))).toEqual({ type: 'string', value: 'full-name' })
})

test("TRY_LOAD - with different value types", async () => {
  // Array
  const str1 = `
  PUSH 1
  PUSH 2
  PUSH 3
  MAKE_ARRAY #3
  STORE arr
  TRY_LOAD arr
  `
  const result1 = await run(toBytecode(str1))
  expect(result1.type).toBe('array')

  // Dict
  const str2 = `
  PUSH 'key'
  PUSH 'value'
  MAKE_DICT #1
  STORE dict
  TRY_LOAD dict
  `
  const result2 = await run(toBytecode(str2))
  expect(result2.type).toBe('dict')

  // Boolean
  const str3 = `
  PUSH true
  STORE flag
  TRY_LOAD flag
  `
  expect(await run(toBytecode(str3))).toEqual({ type: 'boolean', value: true })

  // Null
  const str4 = `
  PUSH null
  STORE empty
  TRY_LOAD empty
  `
  expect(await run(toBytecode(str4))).toEqual({ type: 'null', value: null })
})

test("TRY_LOAD - in nested scope", async () => {
  // Function should be able to TRY_LOAD variable from parent scope
  const str = `
  PUSH 42
  STORE outer
  MAKE_FUNCTION () .fn
  PUSH 0
  PUSH 0
  CALL
  HALT
  .fn:
  TRY_LOAD outer
  RETURN
  `
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 42 })
})

test("TRY_LOAD - missing variable in nested scope returns name", async () => {
  // If variable doesn't exist in any scope, should return name as string
  const str = `
  PUSH 42
  STORE outer
  MAKE_FUNCTION () .fn
  PUSH 0
  PUSH 0
  CALL
  HALT
  .fn:
  TRY_LOAD inner
  RETURN
  `
  expect(await run(toBytecode(str))).toEqual({ type: 'string', value: 'inner' })
})

test("TRY_LOAD - used for conditional variable existence check", async () => {
  // Pattern: use TRY_LOAD to check if variable exists and get its value or name
  const str = `
  PUSH 100
  STORE count
  TRY_LOAD count
  PUSH 'count'
  EQ
  `
  // Variable exists, so TRY_LOAD returns 100, which != 'count'
  expect(await run(toBytecode(str))).toEqual({ type: 'boolean', value: false })

  const str2 = `
  PUSH 100
  STORE count
  TRY_LOAD missing
  PUSH 'missing'
  EQ
  `
  // Variable missing, so TRY_LOAD returns 'missing', which == 'missing'
  expect(await run(toBytecode(str2))).toEqual({ type: 'boolean', value: true })
})

test("TRY_LOAD - with function value", async () => {
  const str = `
  MAKE_FUNCTION () .fn
  STORE myFunc
  JUMP .skip
  .fn:
  PUSH 99
  RETURN
  .skip:
  TRY_LOAD myFunc
  `
  const result = await run(toBytecode(str))
  expect(result.type).toBe('function')
})

test("JUMP - relative jump forward", async () => {
  const str = `
  PUSH 1
  JUMP .skip
  PUSH 100
  .skip:
  PUSH 2
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 2 })
})

test("JUMP - forward jump skips instructions", async () => {
  // Use forward jump to skip, demonstrating relative addressing
  const str = `
  PUSH 100
  JUMP .end
  PUSH 200
  PUSH 300
  .end:
  PUSH 400
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 400 })
})

test("JUMP_IF_FALSE - conditional jump when false", async () => {
  const str = `
  PUSH 1
  PUSH 0
  EQ
  JUMP_IF_FALSE .skip
  PUSH 100
  .skip:
  PUSH 42
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 42 })
})

test("JUMP_IF_FALSE - no jump when true", async () => {
  const str = `
  PUSH 1
  JUMP_IF_FALSE .skip
  PUSH 100
  .skip:
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 100 })
})

test("JUMP_IF_TRUE - conditional jump when true", async () => {
  const str = `
  PUSH 1
  JUMP_IF_TRUE .skip
  PUSH 100
  .skip:
  PUSH 42
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 42 })
})

test("MAKE_ARRAY - creates array", async () => {
  const str = `
  PUSH 10
  PUSH 20
  PUSH 30
  MAKE_ARRAY #3
`
  const result = await run(toBytecode(str))
  expect(result.type).toBe('array')
  if (result.type === 'array') {
    expect(result.value).toHaveLength(3)
    expect(result.value[0]).toEqual({ type: 'number', value: 10 })
    expect(result.value[1]).toEqual({ type: 'number', value: 20 })
    expect(result.value[2]).toEqual({ type: 'number', value: 30 })
  }
})

test("ARRAY_GET - gets element", async () => {
  const str = `
  PUSH 10
  PUSH 20
  PUSH 30
  MAKE_ARRAY #3
  PUSH 1
  ARRAY_GET
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 20 })
})

test("ARRAY_SET - sets element", async () => {
  const str = `
  PUSH 10
  PUSH 20
  PUSH 30
  MAKE_ARRAY #3
  DUP
  PUSH 1
  PUSH 99
  ARRAY_SET
  PUSH 1
  ARRAY_GET
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 99 })
})

test("ARRAY_PUSH - appends to array", async () => {
  const str = `
  PUSH 10
  PUSH 20
  MAKE_ARRAY #2
  DUP
  PUSH 30
  ARRAY_PUSH
  ARRAY_LEN
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 3 })
})

test("ARRAY_PUSH - mutates original array", async () => {
  const str = `
  PUSH 10
  PUSH 20
  MAKE_ARRAY #2
  DUP
  PUSH 30
  ARRAY_PUSH
  PUSH 2
  ARRAY_GET
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 30 })
})

test("ARRAY_LEN - gets length", async () => {
  const str = `
  PUSH 10
  PUSH 20
  PUSH 30
  MAKE_ARRAY #3
  ARRAY_LEN
`
  expect(await run(toBytecode(str))).toEqual({ type: 'number', value: 3 })
})

test("MAKE_DICT - creates dict", async () => {
  const str = `
  PUSH 'name'
  PUSH 'Alice'
  PUSH 'age'
  PUSH 30
  MAKE_DICT #2
`
  const result = await run(toBytecode(str))
  expect(result.type).toBe('dict')
  if (result.type === 'dict') {
    expect(result.value.size).toBe(2)
    expect(result.value.get('name')).toEqual({ type: 'string', value: 'Alice' })
    expect(result.value.get('age')).toEqual({ type: 'number', value: 30 })
  }
})

test("DICT_GET - gets value", async () => {
  const str = `
  PUSH 'name'
  PUSH 'Bob'
  MAKE_DICT #1
  PUSH 'name'
  DICT_GET
`
  expect(await run(toBytecode(str))).toEqual({ type: 'string', value: 'Bob' })
})

test("DICT_SET - sets value", async () => {
  const str = `
  MAKE_DICT #0
  DUP
  PUSH 'key'
  PUSH 'value'
  DICT_SET
  PUSH 'key'
  DICT_GET
`
  expect(await run(toBytecode(str))).toEqual({ type: 'string', value: 'value' })
})

test("DICT_HAS - checks key exists", async () => {
  const str = `
  PUSH 'key'
  PUSH 'value'
  MAKE_DICT #1
  PUSH 'key'
  DICT_HAS
`
  expect(await run(toBytecode(str))).toEqual({ type: 'boolean', value: true })
})

test("DICT_HAS - checks key missing", async () => {
  const str = `
  MAKE_DICT #0
  PUSH 'missing'
  DICT_HAS
`
  expect(await run(toBytecode(str))).toEqual({ type: 'boolean', value: false })
})

test("BREAK - throws error when no break target", async () => {
  // BREAK requires a break target frame on the call stack
  // A single function call has no previous frame to mark as break target
  const bytecode = toBytecode(`
    MAKE_FUNCTION () .fn
    PUSH 0
    PUSH 0
    CALL
    HALT
    .fn:
    BREAK
  `)

  try {
    await run(bytecode)
    expect(true).toBe(false)  // Should not reach here
  } catch (e: any) {
    expect(e.message).toContain('no break target found')
  }
})

test("BREAK - exits from nested function call", async () => {
  // BREAK unwinds to the break target (the outer function's frame)
  // Main calls outer, outer calls inner, inner BREAKs back to outer's caller (main)
  const bytecode = toBytecode(`
    MAKE_FUNCTION () .outer
    PUSH 0
    PUSH 0
    CALL
    PUSH 42
    HALT
    .outer:
    MAKE_FUNCTION () .inner
    PUSH 0
    PUSH 0
    CALL
    PUSH 99
    RETURN
    .inner:
    BREAK
  `)

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

test("JUMP backward - simple loop", async () => {
  // Very simple: counter starts at 0, loops 3 times incrementing
  // On 3rd iteration (counter==3), exits and returns counter
  const bytecode = toBytecode(`
    PUSH 0
    STORE counter
    .loop:
    LOAD counter
    PUSH 3
    EQ
    JUMP_IF_FALSE .body
    LOAD counter
    HALT
    .body:
    LOAD counter
    PUSH 1
    ADD
    STORE counter
    JUMP .loop
  `)

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

test("emoji variable names - string format", async () => {
  const bytecode = toBytecode(`
    PUSH 5
    STORE 💎
    LOAD 💎
    HALT
  `)

  const result = await run(bytecode)
  expect(result).toEqual({ type: 'number', value: 5 })
})

test("emoji variable names - array format", async () => {
  const bytecode = toBytecode([
    ["PUSH", 100],
    ["STORE", "💰"],
    ["LOAD", "💰"],
    ["PUSH", 50],
    ["ADD"],
    ["HALT"]
  ])

  const result = await run(bytecode)
  expect(result).toEqual({ type: 'number', value: 150 })
})

test("unicode variable names - Japanese", async () => {
  const bytecode = toBytecode(`
    PUSH 42
    STORE 変数
    LOAD 変数
    HALT
  `)

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

test("unicode variable names - Chinese", async () => {
  const bytecode = toBytecode([
    ["PUSH", 888],
    ["STORE", "数字"],
    ["LOAD", "数字"],
    ["HALT"]
  ])

  const result = await run(bytecode)
  expect(result).toEqual({ type: 'number', value: 888 })
})

test("emoji in function parameters", async () => {
  const bytecode = toBytecode(`
    MAKE_FUNCTION (💎 🌟) .add
    STORE add
    JUMP .after
    .add:
    LOAD 💎
    LOAD 🌟
    ADD
    RETURN
    .after:
    LOAD add
    PUSH 10
    PUSH 20
    PUSH 2
    PUSH 0
    CALL
    HALT
  `)

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

test("emoji with defaults and variadic", async () => {
  const bytecode = toBytecode([
    ["MAKE_FUNCTION", ["🎯=100", "...🎨"], ".fn"],
    ["STORE", "fn"],
    ["JUMP", ".after"],
    [".fn:"],
    ["LOAD", "🎯"],
    ["RETURN"],
    [".after:"],
    ["LOAD", "fn"],
    ["PUSH", 0],
    ["PUSH", 0],
    ["CALL"],
    ["HALT"]
  ])

  const result = await run(bytecode)
  expect(result).toEqual({ type: 'number', value: 100 })
})

test("mixed emoji and regular names", async () => {
  const bytecode = toBytecode([
    ["PUSH", 10],
    ["STORE", "💎"],
    ["PUSH", 20],
    ["STORE", "value"],
    ["PUSH", 30],
    ["STORE", "🌟"],
    ["LOAD", "💎"],
    ["LOAD", "value"],
    ["ADD"],
    ["LOAD", "🌟"],
    ["ADD"],
    ["HALT"]
  ])

  const result = await run(bytecode)
  expect(result).toEqual({ type: 'number', value: 60 })
})