package wikitext_parser

import (
	"fmt"
	"strings"
)

type Template struct {
	Name         string
	IsLink       bool
	Parameters   map[string][]interface{}
	UnkeyedIndex int
}

func NewTemplate(name string, isLink bool) *Template {
	return &Template{
		Name:       name,
		IsLink:     isLink,
		Parameters: make(map[string][]interface{}),
	}
}

func (t *Template) AddParameterUnkeyed(value interface{}) {
	t.AddParameter(fmt.Sprintf("%d", t.UnkeyedIndex), value)
}

func (t *Template) AddParameter(key string, value interface{}) {
	if _, ok := t.Parameters[key]; !ok {
		t.Parameters[key] = make([]interface{}, 0, 1)
	}
	t.Parameters[key] = append(t.Parameters[key], value)
}

func ParseTemplate(text string, index int, depth int, startCharacter byte) (i int, template *Template) {

	var c byte
	lastToken := index

	var key string

	addValue := func() int {
		if lastToken < len(text) && i-lastToken > 0 {
			t := strings.TrimSpace(text[lastToken:i])
			if len(t) > 0 {
				if template == nil {
					template = NewTemplate(t, startCharacter == '[')
				} else {
					if key == "" {
						template.AddParameterUnkeyed(text[lastToken:i])
					} else {
						template.AddParameter(key, text[lastToken:i])
					}
				}
			}

			return len(t)
		}

		return 0
	}
	addKey := func() {
		if lastToken < len(text) && i-lastToken > 0 {
			t := strings.TrimSpace(text[lastToken:i])
			if len(t) > 0 {
				key = t
			}
		}
	}

	afterNewLine := false

	for i = index; i < len(text); i++ {
		c = text[i]

		if startCharacter == '{' && c == '}' && i < len(text)-1 && text[i+1] == '}' { //end of template
			addValue()
			i += 2
			break
		} else if startCharacter == '[' && c == ']' && i < len(text)-1 && text[i+1] == ']' { //end of link
			addValue()
			i += 2
			break
			//template or light might have parameters
		} else if (c == '{' && i < len(text)-1 && text[i+1] == '{') || (c == '[' && i < len(text)-1 && text[i+1] == '[') {
			addValue()
			var tpl *Template
			var scanIndex int
			scanIndex, tpl = ParseTemplate(text, i+2, depth+1, c)
			if tpl != nil {
				if key == "" {
					template.AddParameterUnkeyed(tpl)
				} else {
					template.AddParameter(key, tpl)
				}
			}
			lastToken = scanIndex
			i = scanIndex - 1
		} else if (c == '{' && i < len(text)-1 && text[i+1] != '{' && text[i+1] != '[') || (c == '[' && i < len(text)-1 && text[i+1] != '[' && text[i+1] != '{') {
			addValue()
			var link *Link
			var scanIndex int
			scanIndex, link = ParseLink(text, i+1, depth+1, c)
			if link != nil && template != nil {
				if key == "" {
					template.AddParameterUnkeyed(link)
				} else {
					template.AddParameter(key, link)
				}
			}
			lastToken = scanIndex
			i = scanIndex - 1
		} else if c == '<' { //html trigger
			addValue()
			var html *HTML
			var scanIndex int
			scanIndex, html = ParseHTML(text, i, depth+1)
			if html != nil && template != nil {
				if key == "" {
					template.AddParameterUnkeyed(html)
				} else {
					template.AddParameter(key, html)
				}
			}
			lastToken = scanIndex
			i = scanIndex - 1
		} else if c == '|' {
			hasTemplate := template != nil
			addValue()
			lastToken = i + 1
			if hasTemplate {
				template.UnkeyedIndex++
			}
			key = ""
		} else if c == '\n' {
			addValue()
			lastToken = i + 1
			afterNewLine = true

			if template != nil {
				if key == "" {
					template.AddParameterUnkeyed(NewLineToken{})
				} else {
					template.AddParameter(key, NewLineToken{})
				}
			}
		} else if afterNewLine && (c == '*' || c == '#') {
			addValue()
			var list *UnorderedList
			var scanIndex int
			scanIndex, list = ParseUnorderedList(text, i, depth+1, 1, c)
			if list != nil {
				if key == "" {
					template.AddParameterUnkeyed(list)
				} else {
					template.AddParameter(key, list)
				}
			}
			lastToken = scanIndex
			i = scanIndex - 1
		} else if afterNewLine && c == ';' {
			addValue()
			var list *DescriptionList
			var scanIndex int
			scanIndex, list = ParseDescriptionList(text, i+1, depth+1)
			if list != nil {
				if key == "" {
					template.AddParameterUnkeyed(list)
				} else {
					template.AddParameter(key, list)
				}
			}
			lastToken = scanIndex
			i = scanIndex - 1
		} else if afterNewLine && c == ':' {
			addValue()
			lastToken = i + 1
		} else if c == '=' {
			if key == "" {
				addKey()
				lastToken = i + 1
			}
		}

		if afterNewLine && c != '\n' && c != ' ' && c != '\t' {
			afterNewLine = false
		}
	}

	return
}