package main

import (
	"fmt"
	"strings"
)

const (
	scaleX = 8
	scaleY = 3
)

// https://github.com/qmk/qmk_firmware/blob/master/docs/keycodes.md
var mapSpecialKey = map[string]string{
	"KC_TRNS": "",
	"KC_NO":   "",
	"KC_ENT":  "ENTER",
	"KC_BSPC": "BACKSPACE",
	"KC_SPC":  "SPACE",
	"KC_MINS": "-",
	"KC_EQL":  "=",
	"KC_LBRC": "[",
	"KC_RBRC": "]",
	"KC_BSLS": "\\",
	"KC_SCLN": ";",
	"KC_QUOT": "'",
	"KC_GRV":  "`",
	"KC_COMM": ",",
	"KC_DOT":  ".",
	"KC_SLSH": "/",
	"KC_CAPS": "CAPSLOCK",
	"KC_LALT": "ALT",
	"KC_RALT": "ALT",
	"KC_LGUI": "CMD",
	"KC_RGUI": "CMD",
	"KC_LSFT": "SHIFT",
	"KC_RSFT": "SHIFT",
	"RGB_TOG": "RGBTO",
	"RGB_MOD": "RGBMO",
	"RGB_HUI": "RGBH",
	"RGB_SAI": "RGBS",
	"RGB_VAI": "RGBV",
	// Custom
	"CTL_T(KC_ESC)":  "CTRL ESC",
	"RSFT_T(KC_ENT)": "SHIFT ENTER",
}

func Draw(
	layouts map[string]map[string][]QMKKeyDictionary,
	keymap QMKKeymap,
) string {
	layoutsStr := make([]string, 0, len(layouts))

	// Each keyboard has many layouts
	for layout := range layouts {
		if keymap.Layout != layout {
			continue
		}

		keys, ok := layouts[layout]["layout"]
		if !ok {
			continue
		}

		layoutStr := fmt.Sprintf("Layout %s\n", layout)

		// Preprocess keys
		// Y aka row -> X aka col
		var newMaxX, newMaxY int
		for i := range keys {
			if int(keys[i].W) == 0 {
				keys[i].W = 1
			}

			if int(keys[i].H) == 0 {
				keys[i].H = 1
			}

			// Because 0.25
			keys[i].NewX = int(keys[i].X * scaleX)
			keys[i].NewY = int(keys[i].Y * scaleY)
			keys[i].NewW = int(keys[i].W * scaleX)
			keys[i].NewH = int(keys[i].H * scaleY)

			if keys[i].NewX+keys[i].NewW > newMaxX {
				newMaxX = keys[i].NewX + keys[i].NewW
			}

			if keys[i].NewY+keys[i].NewH > newMaxY {
				newMaxY = keys[i].NewY + keys[i].NewH
			}
		}

		if newMaxX == 0 || newMaxY == 0 {
			continue
		}

		// Each keymap has many layers
		layersStr := make([]string, 0, len(keymap.Layers))
		for iLayer, layer := range keymap.Layers {
			// Preprocess table with space
			table := make([][]string, newMaxY)
			for i := 0; i < newMaxY; i++ {
				// Padding 1 in the right
				table[i] = make([]string, newMaxX+1)
				for j := 0; j <= newMaxX; j++ {
					table[i][j] = " "
				}
			}

			// Fill layout
			count := 0
			for _, key := range keys {
				keyStr := layer[count]

				// Process keyStr
				if newKeyStr, ok := mapSpecialKey[keyStr]; ok {
					keyStr = newKeyStr
				} else if strings.HasPrefix(keyStr, "KC_") {
					keyStr = strings.TrimPrefix(keyStr, "KC_")
				} else if strings.HasPrefix(keyStr, "QK_") {
					keyStr = strings.TrimPrefix(keyStr, "QK_")
				}

				// Padding to center key
				// Why / 2, why - 1 ?
				// Base on my feeling of course
				padding := (key.NewW-len(keyStr))/2 - 1
				if padding <= 0 {
					padding = 1
				}

				// Draw strategy
				// Draw 4 + in corner
				// Draw - on top and bottom
				// Draw | on left and right
				for i := key.NewY; i < key.NewY+key.NewH; i++ {
					for j := key.NewX; j <= key.NewX+key.NewW; j++ {
						if i == key.NewY || i == key.NewY+key.NewH-1 {
							if j == key.NewX || j == key.NewX+key.NewW {
								table[i][j] = "+"
							} else if table[i][j] != "+" {
								table[i][j] = "-"
							}
						} else if i == key.NewY+key.NewH/2 {
							// Write key in the middle
							if j == key.NewX || j == key.NewX+key.NewW {
								table[i][j] = "|"
							} else if len(keyStr) > 0 && j > key.NewX+padding && j < key.NewX+len(keyStr)+padding+1 && j <= key.NewX+key.NewW-padding {
								// Only handle ASCII keyStr
								table[i][j] = string(keyStr[j-key.NewX-padding-1])
							}
						} else {
							if j == key.NewX || j == key.NewX+key.NewW {
								table[i][j] = "|"
							}
						}
					}
				}

				count++
			}

			// Debug table
			// for i := range table {
			// 	s := ""
			// 	for j := range table[i] {
			// 		s += table[i][j]
			// 	}
			// 	fmt.Println(s)
			// }

			// Process new table
			newTable := make([][]string, 0, newMaxY)

			for i := 0; i < newMaxY; i++ {
				// Merge 2 row lines into 1
				// + + ? = +
				// Merge
				// +--+---+
				// +----+--
				// Into
				// +--+-+-+
				if i+1 < newMaxY && table[i][0] == "+" && table[i+1][0] == "+" {
					// fmt.Println("From")
					// fmt.Println(strings.Join(table[i], ""))
					// fmt.Println(strings.Join(table[i+1], ""))

					newTableI := make([]string, newMaxX+1)
					for j := 0; j <= newMaxX; j++ {
						if table[i][j] == "+" || table[i+1][j] == "+" {
							// fmt.Printf("+ [%s] [%s] %d %d\n", table[i][j], table[i+1][j], i, j)
							newTableI[j] = "+"
							continue
						}

						if table[i][j] == "-" || table[i+1][j] == "-" {
							// fmt.Printf("- [%s] [%s] %d %d\n", table[i][j], table[i+1][j], i, j)
							newTableI[j] = "-"
							continue
						}

						// fmt.Printf("S [%s] [%s] %d %d\n", table[i][j], table[i+1][j], i, j)
						newTableI[j] = " "
					}
					// fmt.Println(strings.Join(newTableI, ""))

					newTable = append(newTable, newTableI)
					i++
					continue
				}

				newTable = append(newTable, table[i])
			}

			layerStr := fmt.Sprintf("Layer %d\n", iLayer)
			for i := range newTable {
				for j := range newTable[i] {
					layerStr += newTable[i][j]
				}
				layerStr += "\n"
			}
			layersStr = append(layersStr, layerStr)
		}

		layoutStr += strings.Join(layersStr, "\n")
		layoutsStr = append(layoutsStr, layoutStr)
	}

	return strings.Join(layoutsStr, "\n")
}