package parser

import (
	"bufio"
	"fmt"
	"os"
	"strings"

	"github.com/rwejlgaard/org/internal/model"
)

// Save writes the org file back to disk
func Save(orgFile *model.OrgFile) error {
	file, err := os.Create(orgFile.Path)
	if err != nil {
		return err
	}
	defer file.Close()

	writer := bufio.NewWriter(file)
	defer writer.Flush()

	for _, item := range orgFile.Items {
		if err := writeItem(writer, item); err != nil {
			return err
		}
	}

	return nil
}

// writeItem recursively writes an item and its children
func writeItem(writer *bufio.Writer, item *model.Item) error {
	// Write heading
	stars := strings.Repeat("*", item.Level)
	line := stars
	if item.State != model.StateNone {
		line += " " + string(item.State)
	}
	line += " " + item.Title + "\n"

	if _, err := writer.WriteString(line); err != nil {
		return err
	}

	// Write scheduling info if not already in notes
	hasScheduled := false
	hasDeadline := false
	hasLogbook := false
	for _, note := range item.Notes {
		if strings.Contains(note, "SCHEDULED:") {
			hasScheduled = true
		}
		if strings.Contains(note, "DEADLINE:") {
			hasDeadline = true
		}
		if strings.Contains(note, ":LOGBOOK:") {
			hasLogbook = true
		}
	}

	if item.Scheduled != nil && !hasScheduled {
		scheduledLine := fmt.Sprintf("SCHEDULED: <%s>\n", FormatOrgDate(*item.Scheduled))
		if _, err := writer.WriteString(scheduledLine); err != nil {
			return err
		}
	}

	if item.Deadline != nil && !hasDeadline {
		deadlineLine := fmt.Sprintf("DEADLINE: <%s>\n", FormatOrgDate(*item.Deadline))
		if _, err := writer.WriteString(deadlineLine); err != nil {
			return err
		}
	}

	// Write clock entries in :LOGBOOK: drawer if not already in notes
	if len(item.ClockEntries) > 0 && !hasLogbook {
		if _, err := writer.WriteString(":LOGBOOK:\n"); err != nil {
			return err
		}
		for _, entry := range item.ClockEntries {
			clockLine := fmt.Sprintf("CLOCK: [%s]", formatClockTimestamp(entry.Start))
			if entry.End != nil {
				clockLine += fmt.Sprintf("--[%s]", formatClockTimestamp(*entry.End))
			}
			clockLine += "\n"
			if _, err := writer.WriteString(clockLine); err != nil {
				return err
			}
		}
		if _, err := writer.WriteString(":END:\n"); err != nil {
			return err
		}
	}

	// Write notes
	for _, note := range item.Notes {
		if _, err := writer.WriteString(note + "\n"); err != nil {
			return err
		}
	}

	// Write children
	for _, child := range item.Children {
		if err := writeItem(writer, child); err != nil {
			return err
		}
	}

	return nil
}