/*
Copyright © 2026 Thomas von Dein

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package printer

import (
	"encoding/json"
	"fmt"
	"regexp"
	"sort"
	"strconv"
	"strings"

	"codeberg.org/scip/esctl/pkg/cfg"
	"gopkg.in/yaml.v3"
)

type Table struct {
	Mode       string // tsv, json, yaml
	Headers    []string
	RawHeaders []string
	Entries    [][]any

	rows            [][]string // representation used for printing
	processed       bool
	lenHeaders      []int
	alignInts       bool
	maxwidth        int
	debugGoRoutines bool
}

func NewTable(conf *cfg.Config, columns, rows int) *Table {
	table := new(Table{
		Mode:            conf.Output,
		maxwidth:        cfg.GetTermWidth(),
		debugGoRoutines: conf.DebugGoRoutines,
	})

	table.Headers = make([]string, columns)
	table.RawHeaders = make([]string, columns)
	table.Entries = make([][]any, rows)
	table.lenHeaders = make([]int, columns)
	table.alignInts = conf.AlignInts

	return table
}

func NewTableEmpty(conf *cfg.Config) *Table {
	table := new(Table{
		Mode:            conf.Output,
		maxwidth:        cfg.GetTermWidth(),
		debugGoRoutines: conf.DebugGoRoutines,
	})
	table.alignInts = conf.AlignInts

	return table
}

func (table *Table) WithHeaders(headers ...string) *Table {
	count := len(headers)

	table.Entries = [][]any{}
	table.lenHeaders = make([]int, count)
	table.Headers = make([]string, count)
	table.RawHeaders = make([]string, count)

	table.Addheaders(headers...)

	return table
}

func (table *Table) Print() error {
	var err error

	switch table.Mode {
	case "json":
		err = table.PrintJSON()
	case "yaml":
		err = table.PrintYAML()
	case "csv":
		err = table.PrintCSV()
	default:
		err = table.PrintTSV()
	}

	if table.debugGoRoutines {
		printGoRoutineMetrics()
	}

	return err
}

var (
	ansiCtrlSeq = regexp.MustCompile(`\033.[0-9;]+m`)
)

func (table *Table) PrintYAML() error {
	raw := table.toMap()

	body, err := yaml.Marshal(raw)
	if err != nil {
		return fmt.Errorf("failed to produce YAML output: %w", err)
	}

	fmt.Println(string(body))

	return nil
}

func (table *Table) PrintJSON() error {
	raw := table.toMap()

	body, err := json.MarshalIndent(raw, "", "  ")
	if err != nil {
		return fmt.Errorf("failed to produce JSON output: %w", err)
	}

	fmt.Println(string(body))

	return nil
}

func (table *Table) PrintTSV() error {
	// length's, convert cell types
	table.preprocessRows()

	// output headers
	for idx, header := range table.Headers {
		if idx+1 != len(table.Headers) {
			fmt.Print(header, strings.Repeat(" ", table.lenHeaders[idx]-visibleLen(header)))
		} else {
			// no padding for last header
			fmt.Print(header)
		}

		if idx < len(table.Headers)-1 {
			fmt.Print("  ")
		}
	}

	fmt.Println()

	for _, entries := range table.rows {
		currentWidth := 0
		columns := len(entries)

		for idx, entry := range entries {
			length := visibleLen(entry)

			if length+currentWidth > table.maxwidth &&
				table.maxwidth-currentWidth > 1 &&
				idx == columns-1 {
				//   text is too wide to be put into one line, and
				// it's the last cell, so wrap it
				entry = wrap(table.maxwidth-currentWidth, currentWidth+2, entry)
			}

			currentWidth += table.lenHeaders[idx]

			switch {
			case isInt(entry) && table.alignInts:
				// align right
				fmt.Print(strings.Repeat(" ", table.lenHeaders[idx]-length), entry)
			case length < table.lenHeaders[idx] && idx+1 != len(entries):
				// pad right, if required
				fmt.Print(entry, strings.Repeat(" ", table.lenHeaders[idx]-length))
			default:
				// no padding for last entry
				fmt.Print(entry)
			}

			if idx < len(table.Headers)-1 {
				fmt.Print("  ")
			}
		}

		fmt.Println()
	}

	return nil
}

// Wrap a  text into multiple lines,  first line is not  indented, all
// further lines will be indented.  Used within Print() to print large
// cell text.
func wrap(width, indent int, text string) string {
	if len(text) <= width {
		return text
	}

	wrapped := ""
	line := ""

	for word := range strings.FieldsSeq(text) {
		if len(line)+len(word)+1 <= width {
			// appending word to current line doesn't exceed width
			if line != "" {
				line += " "
			}

			line += word
		} else {
			// it exceeds it, so we need to wrap
			if wrapped == "" {
				// beginning of output, no indenting here
				wrapped = line + "\n"
			} else {
				// we're in the middle of the text, so add the indent
				wrapped += strings.Repeat(" ", indent) + line + "\n"
			}

			// remember the current word for the next round
			line = word
		}
	}

	if line != "" {
		// last line, no newline needed here
		wrapped += strings.Repeat(" ", indent) + line
	}

	return wrapped
}

func (table *Table) PrintCSV() error {
	table.preprocessRows()

	fmt.Println(strings.Join(table.RawHeaders, ","))

	for _, entries := range table.rows {
		row := make([]string, len(entries))

		for idx, entry := range entries {
			if strings.Contains(entry, " ") || strings.Contains(entry, ",") {
				row[idx] = `"` + entry + `"`
			} else {
				row[idx] = entry
			}
		}

		fmt.Println(strings.Join(row, ","))
	}

	return nil
}

func (table *Table) Sort() {
	// sanity checks
	if len(table.Entries) == 0 {
		return
	}

	table.preprocessRows()

	sort.Slice(table.rows, func(i, j int) bool {
		return table.rows[i][0] < table.rows[j][0]
	})
}

func (table *Table) Addheaders(headers ...string) {
	for idx, header := range headers {
		switch table.Mode {
		case "json", "yaml":
			table.Headers[idx] = strings.ReplaceAll(strings.ToLower(header), " ", "_")
		default:
			table.Headers[idx] = Bold(strings.ReplaceAll(strings.ToUpper(header), " ", "-"))
		}

		table.RawHeaders[idx] = header
	}
}

func (table *Table) AddRow(fields ...any) {
	table.Entries = append(table.Entries, fields)
}

func (table *Table) AddRowLate(fields ...any) {
	table.AddRow(fields)

	if !table.processed {
		return
	}

	row := make([]string, len(fields))

	for idx, field := range fields {
		row[idx] = any2string(field)
	}

	table.rows = append(table.rows, row)
}

// needed for json and yaml output
func (table *Table) toMap() []map[string]any {
	raw := make([]map[string]any, len(table.Entries))

	for idx, entries := range table.Entries {
		raw[idx] = make(map[string]any, len(table.Headers))
		for eidx, entry := range entries {
			raw[idx][table.Headers[eidx]] = entry
		}
	}

	return raw
}

// return the length of a string but only visible chars, w/o ansi color escapes
func visibleLen(word string) int {
	return len(ansiCtrlSeq.ReplaceAllLiteralString(word, ""))
}

func isInt(num string) bool {
	if _, err := strconv.Atoi(num); err == nil {
		return true
	}

	return false
}