package main

import (
  "fmt"

  "github.com/jesseduffield/gocui"
)

func handleBranchPress(g *gocui.Gui, v *gocui.View) error {
  branch := getSelectedBranch(v)
  if output, err := gitCheckout(branch.Name, false); err != nil {
    createErrorPanel(g, output)
  }
  return refreshSidePanels(g)
}

func handleForceCheckout(g *gocui.Gui, v *gocui.View) error {
  branch := getSelectedBranch(v)
  return createConfirmationPanel(g, v, "Force Checkout Branch", "Are you sure you want force checkout? You will lose all local changes", func(g *gocui.Gui, v *gocui.View) error {
    if output, err := gitCheckout(branch.Name, true); err != nil {
      createErrorPanel(g, output)
    }
    return refreshSidePanels(g)
  }, nil)
}

func handleCheckoutByName(g *gocui.Gui, v *gocui.View) error {
  createPromptPanel(g, v, "Branch Name:", func(g *gocui.Gui, v *gocui.View) error {
    if output, err := gitCheckout(trimmedContent(v), false); err != nil {
      return createErrorPanel(g, output)
    }
    return refreshSidePanels(g)
  })
  return nil
}

func handleNewBranch(g *gocui.Gui, v *gocui.View) error {
  branch := state.Branches[0]
  createPromptPanel(g, v, "New Branch Name (Branch is off of "+branch.Name+")", func(g *gocui.Gui, v *gocui.View) error {
    if output, err := gitNewBranch(trimmedContent(v)); err != nil {
      return createErrorPanel(g, output)
    }
    refreshSidePanels(g)
    return handleBranchSelect(g, v)
  })
  return nil
}

func handleMerge(g *gocui.Gui, v *gocui.View) error {
  checkedOutBranch := state.Branches[0]
  selectedBranch := getSelectedBranch(v)
  defer refreshSidePanels(g)
  if checkedOutBranch.Name == selectedBranch.Name {
    return createErrorPanel(g, "You cannot merge a branch into itself")
  }
  if output, err := gitMerge(selectedBranch.Name); err != nil {
    return createErrorPanel(g, output)
  }
  return nil
}

func getSelectedBranch(v *gocui.View) Branch {
  lineNumber := getItemPosition(v)
  return state.Branches[lineNumber]
}

func renderBranchesOptions(g *gocui.Gui) error {
  return renderOptionsMap(g, map[string]string{
    "space": "checkout",
    "f":     "force checkout",
    "m":     "merge",
    "c":     "checkout by name",
    "n":     "checkout new branch",
  })
}

// may want to standardise how these select methods work
func handleBranchSelect(g *gocui.Gui, v *gocui.View) error {
  if err := renderBranchesOptions(g); err != nil {
    return err
  }
  // This really shouldn't happen: there should always be a master branch
  if len(state.Branches) == 0 {
    return renderString(g, "main", "No branches for this repo")
  }
  go func() {
    branch := getSelectedBranch(v)
    diff, _ := getBranchDiff(branch.Name, branch.BaseBranch)
    renderString(g, "main", diff)
  }()
  return nil
}

// refreshStatus is called at the end of this because that's when we can
// be sure there is a state.Branches array to pick the current branch from
func refreshBranches(g *gocui.Gui) error {
  g.Update(func(g *gocui.Gui) error {
    v, err := g.View("branches")
    if err != nil {
      panic(err)
    }
    state.Branches = getGitBranches()
    v.Clear()
    for _, branch := range state.Branches {
      fmt.Fprintln(v, branch.DisplayString)
    }
    resetOrigin(v)
    return refreshStatus(g)
  })
  return nil
}