package printer

import (
	"regexp"
	"strconv"
	"strings"
)

var (
	tempRe       = regexp.MustCompile(`(T\d*|B|C):\s*(-?\d+(?:\.\d+)?)\s*/\s*(-?\d+(?:\.\d+)?)`)
	sdRe         = regexp.MustCompile(`(?i)SD printing byte\s+(\d+)\s*/\s*(\d+)`)
	notSDRe      = regexp.MustCompile(`(?i)Not SD printing`)
	sdDoneRe     = regexp.MustCompile(`(?i)Done printing file`)
	fileOpen     = regexp.MustCompile(`(?i)File opened:\s*(\S+)`)
	sdListStart  = regexp.MustCompile(`(?i)^Begin file list`)
	sdListEnd    = regexp.MustCompile(`(?i)^End file list`)
	sdListLongRe = regexp.MustCompile(`"([^"]+)"`)
)

// Parse one line of printer output and mutate s. Returns true if anything changed.
func (s *State) Parse(line string) bool {
	line = strings.TrimSpace(line)
	if line == "" {
		return false
	}
	changed := false

	for _, m := range tempRe.FindAllStringSubmatch(line, -1) {
		tool := m[1]
		cur, _ := strconv.ParseFloat(m[2], 64)
		tgt, _ := strconv.ParseFloat(m[3], 64)
		if s.Temps == nil {
			s.Temps = map[string]TempPair{}
		}
		s.Temps[tool] = TempPair{Current: cur, Target: tgt}
		changed = true
	}

	if s.Firmware == "" {
		if idx := strings.Index(line, "FIRMWARE_NAME:"); idx >= 0 {
			rest := line[idx+len("FIRMWARE_NAME:"):]
			// Cut at the next CAPS_TOKEN: marker that Marlin emits after FIRMWARE_NAME
			for _, sep := range []string{" SOURCE_CODE_URL:", " PROTOCOL_VERSION:", " MACHINE_TYPE:", " EXTRUDER_COUNT:"} {
				if i := strings.Index(rest, sep); i >= 0 {
					rest = rest[:i]
				}
			}
			s.Firmware = strings.TrimSpace(rest)
			if len(s.Firmware) > 48 {
				s.Firmware = s.Firmware[:48]
			}
			if s.Firmware != "" {
				changed = true
			}
		}
	}

	if m := fileOpen.FindStringSubmatch(line); m != nil {
		s.SDFilename = m[1]
		changed = true
	}

	// SD card directory listing (M20). The firmware emits "Begin file list",
	// one entry per line, then "End file list". While we're inside that
	// block, every non-marker line is a file entry; we accumulate into
	// SDFiles. When the block ends we flip SDListing off and leave the
	// completed slice in place for the UI to consume.
	if sdListStart.MatchString(line) {
		s.SDListing = true
		s.SDFiles = s.SDFiles[:0]
		changed = true
	} else if sdListEnd.MatchString(line) {
		if s.SDListing {
			s.SDListing = false
			changed = true
		}
	} else if s.SDListing {
		if f, ok := parseSDFileEntry(line); ok {
			s.SDFiles = append(s.SDFiles, f)
			changed = true
		}
	}

	if m := sdRe.FindStringSubmatch(line); m != nil {
		byteN, _ := strconv.ParseInt(m[1], 10, 64)
		total, _ := strconv.ParseInt(m[2], 10, 64)
		s.SDByte = byteN
		s.SDTotal = total
		if byteN > 0 && total > 0 {
			if s.PrintState != StateSDPrinting && s.PrintState != StatePaused {
				s.PrintState = StateSDPrinting
				if s.SDStart.IsZero() {
					s.SDStart = nowFn()
				}
			} else if s.SDStart.IsZero() {
				s.SDStart = nowFn()
			}
		}
		changed = true
	} else if notSDRe.MatchString(line) {
		if s.PrintState == StateSDPrinting {
			s.PrintState = StateIdle
			s.SDByte, s.SDTotal = 0, 0
			s.SDStart = zeroTime
			changed = true
		}
	} else if sdDoneRe.MatchString(line) {
		s.PrintState = StateIdle
		s.SDByte = s.SDTotal
		changed = true
	}

	return changed
}

// parseSDFileEntry tries to read a single line from inside the
// "Begin file list" / "End file list" block. Marlin emits
// "FILENAME.GCO 123456" or "FILENAME.GCO 123456 \"Long Name.gcode\"".
// Directories are reported with a trailing "/" — we surface them as
// entries too so the user can spot them, even though M23 won't enter them.
func parseSDFileEntry(line string) (SDFile, bool) {
	line = strings.TrimSpace(line)
	if line == "" {
		return SDFile{}, false
	}
	// Strip a trailing long-filename if present, capture it.
	long := ""
	if m := sdListLongRe.FindStringSubmatch(line); m != nil {
		long = m[1]
		line = strings.TrimSpace(line[:strings.Index(line, "\"")])
	}
	fields := strings.Fields(line)
	if len(fields) == 0 {
		return SDFile{}, false
	}
	name := fields[0]
	var size int64
	if len(fields) >= 2 {
		size, _ = strconv.ParseInt(fields[len(fields)-1], 10, 64)
	}
	return SDFile{Name: name, LongName: long, Size: size}, true
}