package textobject

import (
	"fmt"
	"slices"

	"git.gophernest.net/azpect/TextEditor/internal/action"
	"git.gophernest.net/azpect/TextEditor/internal/core"
)

// Map opposite char
var DirectionalDelimiterMap map[rune]rune = map[rune]rune{
	'(': ')',
	'[': ']',
	'{': '}',
	'<': '>',
}

var singleDelimiterList []rune = []rune{'"', '\'', '`'}

func getStartDelimiterFromEnd(d rune) (rune, bool) {
	if slices.Contains(singleDelimiterList, d) {
		return d, true
	}

	for start, end := range DirectionalDelimiterMap {
		if end == d {
			return start, true
		}
	}

	return ' ', false
}

func getEndDelimiterFromStart(d rune) (rune, bool) {
	if slices.Contains(singleDelimiterList, d) {
		return d, true
	}

	end, found := DirectionalDelimiterMap[d]
	return end, found
}

// Delimiter implements text object for words (iw/aw)
type Delimiter struct {
	Char rune
}

// TODO: This should allow for many lines, not just a single line
//
// BUG: This does not work properly when the cursor is not inside a delimiter. If the cursor
// does not fall inside a delimiter range, it should search forward and find the delimiter.
func (to Delimiter) GetRange(m action.Model, cursor core.Position, modifier string) (core.Position, core.Position, core.MotionType) {
	buf := m.ActiveBuffer()
	line := buf.Lines[cursor.Line]

	// Determine which is a starting delimiter and which ends
	_, isStartingDelimiter := DirectionalDelimiterMap[to.Char]
	var (
		startDelim rune
		endDelim   rune
		startFound bool = true
		endFound   bool = true
	)

	if isStartingDelimiter {
		startDelim = to.Char
		endDelim, endFound = getEndDelimiterFromStart(to.Char)
	} else {
		endDelim = to.Char
		startDelim, startFound = getStartDelimiterFromEnd(to.Char)
	}

	if !endFound || !startFound {
		m.SetCommandOutput(&core.CommandOutput{
			Lines:   []string{fmt.Sprintf("Could not find delimiters from '%c'", to.Char)},
			Inline:  true,
			IsError: false,
		})
		return cursor, cursor, core.CharwiseExclusive
	}

	// Find object boundaries
	start, sOk := findDelimiterStart(line, startDelim, cursor.Col, modifier == "a")
	end, eOk := findDelimiterEnd(line, endDelim, cursor.Col, modifier == "a")

	// Handle the case where they are not found
	if !sOk || !eOk {
		return cursor, cursor, core.CharwiseExclusive
	}

	// This happens when nothing is between the delimiter, fixes the bugs we found
	if start.Col > end.Col {
		return cursor, cursor, core.CharwiseExclusive
	}

	// Word object's don't span lines
	start.Line = cursor.Line
	end.Line = cursor.Line

	return start, end, core.CharwiseInclusive
}

func findDelimiterStart(line string, delimiter rune, col int, includeDelimiter bool) (core.Position, bool) {
	for i := col; i >= 0; i-- {
		if rune(line[i]) == delimiter {
			if includeDelimiter {
				return core.Position{Line: 0, Col: i}, true
			}
			return core.Position{Line: 0, Col: i + 1}, true
		}
	}
	return core.Position{Line: 0, Col: 0}, false
}

func findDelimiterEnd(line string, delimiter rune, col int, includeDelimiter bool) (core.Position, bool) {
	for i := col; i < len(line); i++ {
		if rune(line[i]) == delimiter {
			if includeDelimiter {
				return core.Position{Line: 0, Col: i}, true
			}
			return core.Position{Line: 0, Col: i - 1}, true
		}
	}
	return core.Position{Line: 0, Col: 0}, false
}