package table

import (
	"fmt"
	"strings"
	"unicode/utf8"

	"github.com/jedib0t/go-pretty/v6/text"
)

// Render renders the Table in a human-readable "pretty" format. Example:
//  ┌─────┬────────────┬───────────┬────────┬─────────────────────────────┐
//  │   # │ FIRST NAME │ LAST NAME │ SALARY │                             │
//  ├─────┼────────────┼───────────┼────────┼─────────────────────────────┤
//  │   1 │ Arya       │ Stark     │   3000 │                             │
//  │  20 │ Jon        │ Snow      │   2000 │ You know nothing, Jon Snow! │
//  │ 300 │ Tyrion     │ Lannister │   5000 │                             │
//  ├─────┼────────────┼───────────┼────────┼─────────────────────────────┤
//  │     │            │ TOTAL     │  10000 │                             │
//  └─────┴────────────┴───────────┴────────┴─────────────────────────────┘
func (t *Table) Render() string {
	t.initForRender()

	var out strings.Builder
	if t.numColumns > 0 {
		t.renderTitle(&out)

		// top-most border
		t.renderRowsBorderTop(&out)

		// header rows
		t.renderRowsHeader(&out)

		// (data) rows
		t.renderRows(&out, t.rows, renderHint{})

		// footer rows
		t.renderRowsFooter(&out)

		// bottom-most border
		t.renderRowsBorderBottom(&out)

		// caption
		if t.caption != "" {
			out.WriteRune('\n')
			out.WriteString(t.caption)
		}
	}
	return t.render(&out)
}

func (t *Table) renderColumn(out *strings.Builder, row rowStr, colIdx int, maxColumnLength int, hint renderHint) int {
	numColumnsRendered := 1

	// when working on the first column, and autoIndex is true, insert a new
	// column with the row number on it.
	if colIdx == 0 && t.autoIndex {
		hintAutoIndex := hint
		hintAutoIndex.isAutoIndexColumn = true
		t.renderColumnAutoIndex(out, hintAutoIndex)
	}

	// when working on column number 2 or more, render the column separator
	if colIdx > 0 {
		t.renderColumnSeparator(out, row, colIdx, hint)
	}

	// extract the text, convert-case if not-empty and align horizontally
	mergeVertically := t.shouldMergeCellsVertically(colIdx, hint)
	var colStr string
	if mergeVertically {
		// leave colStr empty; align will expand the column as necessary
	} else if colIdx < len(row) {
		colStr = t.getFormat(hint).Apply(row[colIdx])
	}
	align := t.getAlign(colIdx, hint)

	// if horizontal cell merges are enabled, look ahead and see how many cells
	// have the same content and merge them all until a cell with a different
	// content is found; override alignment to Center in this case
	rowConfig := t.getRowConfig(hint)
	if rowConfig.AutoMerge && !hint.isSeparatorRow {
		// get the real row to consider all lines in each column instead of just
		// looking at the current "line"
		rowUnwrapped := t.getRow(hint.rowNumber-1, hint)
		for idx := colIdx + 1; idx < len(rowUnwrapped); idx++ {
			if rowUnwrapped[colIdx] != rowUnwrapped[idx] {
				break
			}
			align = rowConfig.getAutoMergeAlign()
			maxColumnLength += t.getMaxColumnLengthForMerging(idx)
			numColumnsRendered++
		}
	}
	colStr = align.Apply(colStr, maxColumnLength)

	// pad both sides of the column
	if !hint.isSeparatorRow || (hint.isSeparatorRow && mergeVertically) {
		colStr = t.style.Box.PaddingLeft + colStr + t.style.Box.PaddingRight
	}

	t.renderColumnColorized(out, colIdx, colStr, hint)

	return colIdx + numColumnsRendered
}

func (t *Table) renderColumnAutoIndex(out *strings.Builder, hint renderHint) {
	var outAutoIndex strings.Builder
	outAutoIndex.Grow(t.maxColumnLengths[0])

	if hint.isSeparatorRow {
		numChars := t.autoIndexVIndexMaxLength + utf8.RuneCountInString(t.style.Box.PaddingLeft) +
			utf8.RuneCountInString(t.style.Box.PaddingRight)
		chars := t.style.Box.MiddleHorizontal
		if hint.isAutoIndexColumn && hint.isHeaderOrFooterSeparator() {
			chars = text.RepeatAndTrim(" ", len(t.style.Box.MiddleHorizontal))
		}
		outAutoIndex.WriteString(text.RepeatAndTrim(chars, numChars))
	} else {
		outAutoIndex.WriteString(t.style.Box.PaddingLeft)
		rowNumStr := fmt.Sprint(hint.rowNumber)
		if hint.isHeaderRow || hint.isFooterRow || hint.rowLineNumber > 1 {
			rowNumStr = strings.Repeat(" ", t.autoIndexVIndexMaxLength)
		}
		outAutoIndex.WriteString(text.AlignRight.Apply(rowNumStr, t.autoIndexVIndexMaxLength))
		outAutoIndex.WriteString(t.style.Box.PaddingRight)
	}

	if t.style.Color.IndexColumn != nil {
		colors := t.style.Color.IndexColumn
		if hint.isFooterRow {
			colors = t.style.Color.Footer
		}
		out.WriteString(colors.Sprint(outAutoIndex.String()))
	} else {
		out.WriteString(outAutoIndex.String())
	}
	hint.isAutoIndexColumn = true
	t.renderColumnSeparator(out, rowStr{}, 0, hint)
}

func (t *Table) renderColumnColorized(out *strings.Builder, colIdx int, colStr string, hint renderHint) {
	colors := t.getColumnColors(colIdx, hint)
	if colors != nil {
		out.WriteString(colors.Sprint(colStr))
	} else if hint.isHeaderRow && t.style.Color.Header != nil {
		out.WriteString(t.style.Color.Header.Sprint(colStr))
	} else if hint.isFooterRow && t.style.Color.Footer != nil {
		out.WriteString(t.style.Color.Footer.Sprint(colStr))
	} else if hint.isRegularRow() {
		if colIdx == t.indexColumn-1 && t.style.Color.IndexColumn != nil {
			out.WriteString(t.style.Color.IndexColumn.Sprint(colStr))
		} else if hint.rowNumber%2 == 0 && t.style.Color.RowAlternate != nil {
			out.WriteString(t.style.Color.RowAlternate.Sprint(colStr))
		} else if t.style.Color.Row != nil {
			out.WriteString(t.style.Color.Row.Sprint(colStr))
		} else {
			out.WriteString(colStr)
		}
	} else {
		out.WriteString(colStr)
	}
}

func (t *Table) renderColumnSeparator(out *strings.Builder, row rowStr, colIdx int, hint renderHint) {
	if t.style.Options.SeparateColumns {
		separator := t.getColumnSeparator(row, colIdx, hint)

		colors := t.getSeparatorColors(hint)
		if colors.EscapeSeq() != "" {
			out.WriteString(colors.Sprint(separator))
		} else {
			out.WriteString(separator)
		}
	}
}

func (t *Table) renderLine(out *strings.Builder, row rowStr, hint renderHint) {
	// if the output has content, it means that this call is working on line
	// number 2 or more; separate them with a newline
	if out.Len() > 0 {
		out.WriteRune('\n')
	}

	// use a brand-new strings.Builder if a row length limit has been set
	var outLine *strings.Builder
	if t.allowedRowLength > 0 {
		outLine = &strings.Builder{}
	} else {
		outLine = out
	}
	// grow the strings.Builder to the maximum possible row length
	outLine.Grow(t.maxRowLength)

	nextColIdx := 0
	t.renderMarginLeft(outLine, hint)
	for colIdx, maxColumnLength := range t.maxColumnLengths {
		if colIdx != nextColIdx {
			continue
		}
		nextColIdx = t.renderColumn(outLine, row, colIdx, maxColumnLength, hint)
	}
	t.renderMarginRight(outLine, hint)

	// merge the strings.Builder objects if a new one was created earlier
	if outLine != out {
		t.renderLineMergeOutputs(out, outLine)
	}

	// if a page size has been set, and said number of lines has already
	// been rendered, and the header is not being rendered right now, render
	// the header all over again with a spacing line
	if hint.isRegularRow() {
		t.numLinesRendered++
		if t.pageSize > 0 && t.numLinesRendered%t.pageSize == 0 && !hint.isLastLineOfLastRow() {
			t.renderRowsFooter(out)
			t.renderRowsBorderBottom(out)
			out.WriteString(t.style.Box.PageSeparator)
			t.renderRowsBorderTop(out)
			t.renderRowsHeader(out)
		}
	}
}

func (t *Table) renderLineMergeOutputs(out *strings.Builder, outLine *strings.Builder) {
	outLineStr := outLine.String()
	if text.RuneWidthWithoutEscSequences(outLineStr) > t.allowedRowLength {
		trimLength := t.allowedRowLength - utf8.RuneCountInString(t.style.Box.UnfinishedRow)
		if trimLength > 0 {
			out.WriteString(text.Trim(outLineStr, trimLength))
			out.WriteString(t.style.Box.UnfinishedRow)
		}
	} else {
		out.WriteString(outLineStr)
	}
}

func (t *Table) renderMarginLeft(out *strings.Builder, hint renderHint) {
	out.WriteString(t.style.Format.Direction.Modifier())
	if t.style.Options.DrawBorder {
		border := t.getBorderLeft(hint)
		colors := t.getBorderColors(hint)
		if colors.EscapeSeq() != "" {
			out.WriteString(colors.Sprint(border))
		} else {
			out.WriteString(border)
		}
	}
}

func (t *Table) renderMarginRight(out *strings.Builder, hint renderHint) {
	if t.style.Options.DrawBorder {
		border := t.getBorderRight(hint)
		colors := t.getBorderColors(hint)
		if colors.EscapeSeq() != "" {
			out.WriteString(colors.Sprint(border))
		} else {
			out.WriteString(border)
		}
	}
}

func (t *Table) renderRow(out *strings.Builder, row rowStr, hint renderHint) {
	if len(row) > 0 {
		// fit every column into the allowedColumnLength/maxColumnLength limit
		// and in the process find the max. number of lines in any column in
		// this row
		colMaxLines, rowWrapped := t.wrapRow(row)

		// if there is just 1 line in all columns, add the row as such; else
		// split each column into individual lines and render them one-by-one
		if colMaxLines == 1 {
			hint.isLastLineOfRow = true
			t.renderLine(out, rowWrapped, hint)
		} else {
			// convert one row into N # of rows based on colMaxLines
			rowLines := make([]rowStr, len(row))
			for colIdx, colStr := range rowWrapped {
				rowLines[colIdx] = t.getVAlign(colIdx, hint).ApplyStr(colStr, colMaxLines)
			}
			for colLineIdx := 0; colLineIdx < colMaxLines; colLineIdx++ {
				rowLine := make(rowStr, len(rowLines))
				for colIdx, colLines := range rowLines {
					rowLine[colIdx] = colLines[colLineIdx]
				}
				hint.isLastLineOfRow = colLineIdx == colMaxLines-1
				hint.rowLineNumber = colLineIdx + 1
				t.renderLine(out, rowLine, hint)
			}
		}
	}
}

func (t *Table) renderRowSeparator(out *strings.Builder, hint renderHint) {
	if hint.isBorderTop || hint.isBorderBottom {
		if !t.style.Options.DrawBorder {
			return
		}
	} else if hint.isHeaderRow && !t.style.Options.SeparateHeader {
		return
	} else if hint.isFooterRow && !t.style.Options.SeparateFooter {
		return
	}
	hint.isSeparatorRow = true
	t.renderLine(out, t.rowSeparator, hint)
}

func (t *Table) renderRows(out *strings.Builder, rows []rowStr, hint renderHint) {
	for rowIdx, row := range rows {
		hint.isFirstRow = rowIdx == 0
		hint.isLastRow = rowIdx == len(rows)-1
		hint.rowNumber = rowIdx + 1
		t.renderRow(out, row, hint)

		if (t.style.Options.SeparateRows && rowIdx < len(rows)-1) || // last row before footer
			(t.separators[rowIdx] && rowIdx != len(rows)-1) { // manually added separator not after last row
			hint.isFirstRow = false
			t.renderRowSeparator(out, hint)
		}
	}
}

func (t *Table) renderRowsBorderBottom(out *strings.Builder) {
	if len(t.rowsFooter) > 0 {
		t.renderRowSeparator(out, renderHint{isBorderBottom: true, isFooterRow: true, rowNumber: len(t.rowsFooter)})
	} else {
		t.renderRowSeparator(out, renderHint{isBorderBottom: true, isFooterRow: false, rowNumber: len(t.rows)})
	}
}

func (t *Table) renderRowsBorderTop(out *strings.Builder) {
	if len(t.rowsHeader) > 0 || t.autoIndex {
		t.renderRowSeparator(out, renderHint{isBorderTop: true, isHeaderRow: true, rowNumber: 0})
	} else {
		t.renderRowSeparator(out, renderHint{isBorderTop: true, isHeaderRow: false, rowNumber: 0})
	}
}

func (t *Table) renderRowsFooter(out *strings.Builder) {
	if len(t.rowsFooter) > 0 {
		t.renderRowSeparator(out, renderHint{
			isFooterRow:    true,
			isFirstRow:     true,
			isSeparatorRow: true,
		})
		t.renderRows(out, t.rowsFooter, renderHint{isFooterRow: true})
	}
}

func (t *Table) renderRowsHeader(out *strings.Builder) {
	if len(t.rowsHeader) > 0 || t.autoIndex {
		hintSeparator := renderHint{isHeaderRow: true, isLastRow: true, isSeparatorRow: true}

		if len(t.rowsHeader) > 0 {
			t.renderRows(out, t.rowsHeader, renderHint{isHeaderRow: true})
			hintSeparator.rowNumber = len(t.rowsHeader)
		} else if t.autoIndex {
			t.renderRow(out, t.getAutoIndexColumnIDs(), renderHint{isAutoIndexRow: true, isHeaderRow: true})
			hintSeparator.rowNumber = 1
		}
		t.renderRowSeparator(out, hintSeparator)
	}
}

func (t *Table) renderTitle(out *strings.Builder) {
	if t.title != "" {
		colors := t.style.Title.Colors
		colorsBorder := t.getBorderColors(renderHint{isTitleRow: true})
		rowLength := t.maxRowLength
		if t.allowedRowLength != 0 && t.allowedRowLength < rowLength {
			rowLength = t.allowedRowLength
		}
		if t.style.Options.DrawBorder {
			lenBorder := rowLength - text.RuneWidthWithoutEscSequences(t.style.Box.TopLeft+t.style.Box.TopRight)
			out.WriteString(colorsBorder.Sprint(t.style.Box.TopLeft))
			out.WriteString(colorsBorder.Sprint(text.RepeatAndTrim(t.style.Box.MiddleHorizontal, lenBorder)))
			out.WriteString(colorsBorder.Sprint(t.style.Box.TopRight))
		}

		lenText := rowLength - text.RuneWidthWithoutEscSequences(t.style.Box.PaddingLeft+t.style.Box.PaddingRight)
		if t.style.Options.DrawBorder {
			lenText -= text.RuneWidthWithoutEscSequences(t.style.Box.Left + t.style.Box.Right)
		}
		titleText := text.WrapText(t.title, lenText)
		for _, titleLine := range strings.Split(titleText, "\n") {
			t.renderTitleLine(out, lenText, titleLine, colors, colorsBorder)
		}
	}
}

func (t *Table) renderTitleLine(out *strings.Builder, lenText int, titleLine string, colors text.Colors, colorsBorder text.Colors) {
	titleLine = strings.TrimSpace(titleLine)
	titleLine = t.style.Title.Format.Apply(titleLine)
	titleLine = t.style.Title.Align.Apply(titleLine, lenText)
	titleLine = t.style.Box.PaddingLeft + titleLine + t.style.Box.PaddingRight

	if out.Len() > 0 {
		out.WriteRune('\n')
	}
	if t.style.Options.DrawBorder {
		out.WriteString(colorsBorder.Sprint(t.style.Box.Left))
	}
	out.WriteString(colors.Sprint(titleLine))
	if t.style.Options.DrawBorder {
		out.WriteString(colorsBorder.Sprint(t.style.Box.Right))
	}
}