package tui

import (
	"github.com/charmbracelet/lipgloss"
	"github.com/charmbracelet/lipgloss/table"
)

var (
	tableHeaderStyle   lipgloss.Style
	tableCellStyle     lipgloss.Style
	tableSelectedStyle lipgloss.Style
	tableBorderStyle   lipgloss.Style
	tableZebraStyle    lipgloss.Style
)

type StyleOverride func(row, col int) *lipgloss.Style

type colDef struct {
	short    string
	full     string
	minWidth int
	maxWidth int
	flex     bool
}

func (m Model) computeTableLayout(cols []colDef, maxContentWidth int) ([]string, []int) {
	numCols := len(cols)
	borderOverhead := 2 + (numCols - 1)
	usable := m.termWidth - chromePadH - 2 - borderOverhead
	if usable < 40 {
		usable = 40
	}

	fixedMin := 0
	flexIdx := -1
	for i, c := range cols {
		if c.flex {
			flexIdx = i
			continue
		}
		fixedMin += c.minWidth
	}

	flexW := usable - fixedMin
	if maxContentWidth > 0 && flexW > maxContentWidth {
		flexW = maxContentWidth
	}
	if flexW < 8 {
		flexW = 8
	}

	surplus := usable - fixedMin - flexW
	if surplus < 0 {
		surplus = 0
	}

	headers := make([]string, numCols)
	widths := make([]int, numCols)
	for i, c := range cols {
		if c.flex {
			headers[i] = c.full
			widths[i] = flexW
			continue
		}

		w := c.minWidth
		expand := c.maxWidth - c.minWidth
		if surplus >= expand {
			w = c.maxWidth
			surplus -= expand
		} else if surplus > 0 {
			w += surplus
			surplus = 0
		}

		if w >= len(c.full)+2 {
			headers[i] = c.full
		} else {
			headers[i] = c.short
		}
		widths[i] = w
	}

	if surplus > 0 && flexIdx >= 0 {
		widths[flexIdx] += surplus
	}

	return headers, widths
}

func (m Model) renderTable(headers []string, items int, buildRows func(start, end int) [][]string, colWidths []int, styleOverride StyleOverride) string {
	if items == 0 {
		return ""
	}

	end := m.tableOffset + m.maxTableRows
	if end > items {
		end = items
	}

	selectedVisual := m.cursor - m.tableOffset
	rows := buildRows(m.tableOffset, end)

	tableWidth := m.termWidth - chromePadH - 2
	if tableWidth < 40 {
		tableWidth = 40
	}

	t := table.New().
		Border(lipgloss.RoundedBorder()).
		BorderStyle(tableBorderStyle).
		Width(tableWidth).
		Headers(headers...).
		Rows(rows...).
		StyleFunc(func(row, col int) lipgloss.Style {
			if row == table.HeaderRow {
				h := tableHeaderStyle
				if col < len(colWidths) && colWidths[col] > 0 {
					h = h.Width(colWidths[col]).MaxWidth(colWidths[col])
				}
				return h
			}
			isSelected := row == selectedVisual
			if styleOverride != nil {
				if s := styleOverride(row, col); s != nil {
					style := *s
					if isSelected {
						style = tableSelectedStyle.Foreground(s.GetForeground())
					}
					if col < len(colWidths) && colWidths[col] > 0 {
						style = style.Width(colWidths[col]).MaxWidth(colWidths[col])
					}
					return style
				}
			}
			base := tableCellStyle
			if row%2 == 1 {
				base = tableZebraStyle
			}
			if isSelected {
				base = tableSelectedStyle
			}
			if col < len(colWidths) && colWidths[col] > 0 {
				base = base.Width(colWidths[col]).MaxWidth(colWidths[col])
			}
			return base
		})

	return "\n" + t.Render()
}