// assemblyPerSourceLine disassembles the binary containing a symbol
// and classifies the assembly instructions according to its
// corresponding source line, annotating them with a set of samples.
func assemblyPerSourceLine(objSyms []*objSymbol, rs graph.Nodes, src string, obj plugin.ObjTool) map[int]graph.Nodes {
	assembly := make(map[int]graph.Nodes)
	// Identify symbol to use for this collection of samples.
	o := findMatchingSymbol(objSyms, rs)
	if o == nil {
		return assembly
	}

	// Extract assembly for matched symbol
	insns, err := obj.Disasm(o.sym.File, o.sym.Start, o.sym.End)
	if err != nil {
		return assembly
	}

	srcBase := filepath.Base(src)
	anodes := annotateAssembly(insns, rs, o.base)
	var lineno = 0
	for _, an := range anodes {
		if filepath.Base(an.Info.File) == srcBase {
			lineno = an.Info.Lineno
		}
		if lineno != 0 {
			assembly[lineno] = append(assembly[lineno], an)
		}
	}

	return assembly
}

// printAssembly prints an annotated assembly listing.
func printAssembly(w io.Writer, rpt *Report, obj plugin.ObjTool) error {
	o := rpt.options
	prof := rpt.prof

	g := rpt.newGraph(nil)

	// If the regexp source can be parsed as an address, also match
	// functions that land on that address.
	var address *uint64
	if hex, err := strconv.ParseUint(o.Symbol.String(), 0, 64); err == nil {
		address = &hex
	}

	fmt.Fprintln(w, "Total:", rpt.formatValue(rpt.total))
	symbols := symbolsFromBinaries(prof, g, o.Symbol, address, obj)
	symNodes := nodesPerSymbol(g.Nodes, symbols)
	// Sort function names for printing.
	var syms objSymbols
	for s := range symNodes {
		syms = append(syms, s)
	}
	sort.Sort(syms)

	// Correlate the symbols from the binary with the profile samples.
	for _, s := range syms {
		sns := symNodes[s]

		// Gather samples for this symbol.
		flatSum, cumSum := sns.Sum()

		// Get the function assembly.
		insns, err := obj.Disasm(s.sym.File, s.sym.Start, s.sym.End)
		if err != nil {
			return err
		}

		ns := annotateAssembly(insns, sns, s.base)

		fmt.Fprintf(w, "ROUTINE ======================== %s\n", s.sym.Name[0])
		for _, name := range s.sym.Name[1:] {
			fmt.Fprintf(w, "    AKA ======================== %s\n", name)
		}
		fmt.Fprintf(w, "%10s %10s (flat, cum) %s of Total\n",
			rpt.formatValue(flatSum), rpt.formatValue(cumSum),
			percentage(cumSum, rpt.total))

		for _, n := range ns {
			fmt.Fprintf(w, "%10s %10s %10x: %s\n", valueOrDot(n.Flat, rpt), valueOrDot(n.Cum, rpt), n.Info.Address, n.Info.Name)
		}
	}
	return nil
}

// locateBinaries searches for binary files listed in the profile and, if found,
// updates the profile accordingly.
func locateBinaries(p *profile.Profile, s *source, obj plugin.ObjTool, ui plugin.UI) {
	// Construct search path to examine
	searchPath := os.Getenv("PPROF_BINARY_PATH")
	if searchPath == "" {
		// Use $HOME/pprof/binaries as default directory for local symbolization binaries
		searchPath = filepath.Join(os.Getenv("HOME"), "pprof", "binaries")
	}

mapping:
	for i, m := range p.Mapping {
		var baseName string
		// Replace executable filename/buildID with the overrides from source.
		// Assumes the executable is the first Mapping entry.
		if i == 0 {
			if s.ExecName != "" {
				m.File = s.ExecName
			}
			if s.BuildID != "" {
				m.BuildID = s.BuildID
			}
		}
		if m.File != "" {
			baseName = filepath.Base(m.File)
		}

		for _, path := range filepath.SplitList(searchPath) {
			var fileNames []string
			if m.BuildID != "" {
				fileNames = []string{filepath.Join(path, m.BuildID, baseName)}
				if matches, err := filepath.Glob(filepath.Join(path, m.BuildID, "*")); err == nil {
					fileNames = append(fileNames, matches...)
				}
			}
			if baseName != "" {
				fileNames = append(fileNames, filepath.Join(path, baseName))
			}
			for _, name := range fileNames {
				if f, err := obj.Open(name, m.Start, m.Limit, m.Offset); err == nil {
					defer f.Close()
					fileBuildID := f.BuildID()
					if m.BuildID != "" && m.BuildID != fileBuildID {
						ui.PrintErr("Ignoring local file " + name + ": build-id mismatch (" + m.BuildID + " != " + fileBuildID + ")")
					} else {
						m.File = name
						continue mapping
					}
				}
			}
		}
	}
}

// symbolsFromBinaries examines the binaries listed on the profile
// that have associated samples, and identifies symbols matching rx.
func symbolsFromBinaries(prof *profile.Profile, g *graph.Graph, rx *regexp.Regexp, address *uint64, obj plugin.ObjTool) []*objSymbol {
	hasSamples := make(map[string]bool)
	// Only examine mappings that have samples that match the
	// regexp. This is an optimization to speed up pprof.
	for _, n := range g.Nodes {
		if name := n.Info.PrintableName(); rx.MatchString(name) && n.Info.Objfile != "" {
			hasSamples[n.Info.Objfile] = true
		}
	}

	// Walk all mappings looking for matching functions with samples.
	var objSyms []*objSymbol
	for _, m := range prof.Mapping {
		if !hasSamples[filepath.Base(m.File)] {
			if address == nil || !(m.Start <= *address && *address <= m.Limit) {
				continue
			}
		}

		f, err := obj.Open(m.File, m.Start, m.Limit, m.Offset)
		if err != nil {
			fmt.Printf("%v\n", err)
			continue
		}

		// Find symbols in this binary matching the user regexp.
		var addr uint64
		if address != nil {
			addr = *address
		}
		msyms, err := f.Symbols(rx, addr)
		base := f.Base()
		f.Close()
		if err != nil {
			continue
		}
		for _, ms := range msyms {
			objSyms = append(objSyms,
				&objSymbol{
					sym:  ms,
					base: base,
				},
			)
		}
	}

	return objSyms
}

// newMapping creates a mappingTable for a profile.
func newMapping(prof *profile.Profile, obj plugin.ObjTool, ui plugin.UI, force bool) (*mappingTable, error) {
	mt := &mappingTable{
		prof:     prof,
		segments: make(map[*profile.Mapping]plugin.ObjFile),
	}

	// Identify used mappings
	mappings := make(map[*profile.Mapping]bool)
	for _, l := range prof.Location {
		mappings[l.Mapping] = true
	}

	for _, m := range prof.Mapping {
		if !mappings[m] {
			continue
		}

		// Do not attempt to re-symbolize a mapping that has already been symbolized.
		if !force && (m.HasFunctions || m.HasFilenames || m.HasLineNumbers) {
			continue
		}

		// Skip well-known system mappings
		name := filepath.Base(m.File)
		if name == "" || name == "[vdso]" || strings.HasPrefix(name, "linux-vdso") {
			continue
		}

		f, err := obj.Open(m.File, m.Start, m.Limit, m.Offset)
		if err != nil {
			ui.PrintErr("Local symbolization failed for ", name, ": ", err)
			continue
		}
		if fid := f.BuildID(); m.BuildID != "" && fid != "" && fid != m.BuildID {
			ui.PrintErr("Local symbolization failed for ", name, ": build ID mismatch")
			f.Close()
			continue
		}

		mt.segments[m] = f
	}

	return mt, nil
}

// newMapping creates a mappingTable for a profile.
func newMapping(prof *profile.Profile, obj plugin.ObjTool, ui plugin.UI, force bool) (*mappingTable, error) {
	mt := &mappingTable{
		prof:     prof,
		segments: make(map[*profile.Mapping]plugin.ObjFile),
	}

	// Identify used mappings
	mappings := make(map[*profile.Mapping]bool)
	for _, l := range prof.Location {
		mappings[l.Mapping] = true
	}

	missingBinaries := false
	for midx, m := range prof.Mapping {
		if !mappings[m] {
			continue
		}

		// Do not attempt to re-symbolize a mapping that has already been symbolized.
		if !force && (m.HasFunctions || m.HasFilenames || m.HasLineNumbers) {
			continue
		}

		if m.File == "" {
			if midx == 0 {
				ui.PrintErr("Main binary filename not available.\n" +
					"Try passing the path to the main binary before the profile.")
				continue
			}
			missingBinaries = true
			continue
		}

		// Skip well-known system mappings
		name := filepath.Base(m.File)
		if name == "[vdso]" || strings.HasPrefix(name, "linux-vdso") {
			continue
		}

		// Skip mappings pointing to a source URL
		if m.BuildID == "" {
			if u, err := url.Parse(m.File); err == nil && u.IsAbs() {
				continue
			}
		}

		f, err := obj.Open(m.File, m.Start, m.Limit, m.Offset)
		if err != nil {
			ui.PrintErr("Local symbolization failed for ", name, ": ", err)
			continue
		}
		if fid := f.BuildID(); m.BuildID != "" && fid != "" && fid != m.BuildID {
			ui.PrintErr("Local symbolization failed for ", name, ": build ID mismatch")
			f.Close()
			continue
		}

		mt.segments[m] = f
	}
	if missingBinaries {
		ui.PrintErr("Some binary filenames not available. Symbolization may be incomplete.")
	}
	return mt, nil
}