/*!
 * Copyright (c) Squirrel Chat et al., All rights reserved.
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holder nor the names of its contributors
 *    may be used to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import { type IntegersAsBigInt, parseString } from './primitive.js'
import { extractValue } from './extract.js'
import { indexOfNewline, skipComment, skipVoid, type TomlTable, type TomlValue } from './util.js'
import { TomlError } from './error.js'

let KEY_PART_RE = /^[a-zA-Z0-9-_]+[ \t]*$/

/** @internal */
export function parseKey(str: string, ptr: number, end = '='): [string[], number] {
	let dot = ptr - 1
	let parsed = []

	let endPtr = str.indexOf(end, ptr)
	if (endPtr < 0) {
		throw new TomlError('incomplete key-value: cannot find end of key', {
			toml: str,
			ptr: ptr,
		})
	}

	do {
		let c = str[(ptr = ++dot)]

		// If it's whitespace, ignore
		if (c !== ' ' && c !== '\t') {
			// If it's a string
			if (c === '"' || c === "'") {
				if (c === str[ptr + 1] && c === str[ptr + 2]) {
					throw new TomlError('multiline strings are not allowed in keys', {
						toml: str,
						ptr: ptr,
					})
				}

				let [part, eos] = parseString(str, ptr)
				dot = str.indexOf('.', eos)

				let strEnd = str.slice(eos, dot < 0 || dot > endPtr ? endPtr : dot)
				let newLine = indexOfNewline(strEnd)
				if (newLine > -1) {
					throw new TomlError('newlines are not allowed in keys', {
						toml: str,
						ptr: ptr + dot + newLine,
					})
				}

				if (strEnd.trimStart()) {
					throw new TomlError('found extra tokens after the string part', {
						toml: str,
						ptr: eos,
					})
				}

				if (endPtr < eos) {
					endPtr = str.indexOf(end, eos)
					if (endPtr < 0) {
						throw new TomlError('incomplete key-value: cannot find end of key', {
							toml: str,
							ptr: ptr,
						})
					}
				}

				parsed.push(part)
			} else {
				// Normal raw key part consumption and validation
				dot = str.indexOf('.', ptr)
				let part = str.slice(ptr, dot < 0 || dot > endPtr ? endPtr : dot)
				if (!KEY_PART_RE.test(part)) {
					throw new TomlError('only letter, numbers, dashes and underscores are allowed in keys', {
						toml: str,
						ptr: ptr,
					})
				}

				parsed.push(part.trimEnd())
			}
		}
		// Until there's no more dot
	} while (dot + 1 && dot < endPtr)

	return [parsed, skipVoid(str, endPtr + 1, true, true)]
}

/** @internal */
export function parseInlineTable(str: string, ptr: number, depth: number, integersAsBigInt: IntegersAsBigInt): [TomlTable, number] {
	let res: TomlTable = {}
	let seen = new Set()
	let c: string

	ptr++
	while ((c = str[ptr++]!) !== '}' && c) {
		if (c === ',') {
			throw new TomlError('expected value, found comma', {
				toml: str,
				ptr: ptr - 1,
			})
		} else if (c === '#') ptr = skipComment(str, ptr)
		else if (c !== ' ' && c !== '\t' && c !== '\n' && c !== '\r') {
			let k: string
			let t: any = res
			let hasOwn = false

			let [key, keyEndPtr] = parseKey(str, ptr - 1)
			for (let i = 0; i < key.length; i++) {
				if (i) t = hasOwn! ? t[k!] : (t[k!] = {})

				k = key[i]!
				if ((hasOwn = Object.hasOwn(t, k)) && (typeof t[k] !== 'object' || seen.has(t[k]))) {
					throw new TomlError('trying to redefine an already defined value', {
						toml: str,
						ptr: ptr,
					})
				}

				if (!hasOwn && k === '__proto__') {
					Object.defineProperty(t, k, { enumerable: true, configurable: true, writable: true })
				}
			}

			if (hasOwn) {
				throw new TomlError('trying to redefine an already defined value', {
					toml: str,
					ptr: ptr,
				})
			}

			let [value, valueEndPtr] = extractValue(str, keyEndPtr, '}', depth - 1, integersAsBigInt)
			seen.add(value)

			t[k!] = value
			ptr = valueEndPtr
		}
	}

	if (!c) {
		throw new TomlError('unfinished table encountered', {
			toml: str,
			ptr: ptr,
		})
	}

	return [res, ptr]
}

/** @internal */
export function parseArray(str: string, ptr: number, depth: number, integersAsBigInt: IntegersAsBigInt): [TomlValue[], number] {
	let res: TomlValue[] = []
	let c

	ptr++
	while ((c = str[ptr++]) !== ']' && c) {
		if (c === ',') {
			throw new TomlError('expected value, found comma', {
				toml: str,
				ptr: ptr - 1,
			})
		} else if (c === '#') ptr = skipComment(str, ptr)
		else if (c !== ' ' && c !== '\t' && c !== '\n' && c !== '\r') {
			let e = extractValue(str, ptr - 1, ']', depth - 1, integersAsBigInt)
			res.push(e[0])
			ptr = e[1]
		}
	}

	if (!c) {
		throw new TomlError('unfinished array encountered', {
			toml: str,
			ptr: ptr,
		})
	}

	return [res, ptr]
}